* [Qemu-devel] [PATCH V3 1/2] [SLIRP] Simple ARP table
@ 2011-08-01 16:18 Fabien Chouteau
2011-08-01 16:18 ` [Qemu-devel] [PATCH V3 2/2] [SLIRP] Delayed IP packets Fabien Chouteau
2011-08-01 20:16 ` [Qemu-devel] [PATCH V3 1/2] [SLIRP] Simple ARP table Jan Kiszka
0 siblings, 2 replies; 8+ messages in thread
From: Fabien Chouteau @ 2011-08-01 16:18 UTC (permalink / raw)
To: qemu-devel; +Cc: jan.kiszka
This patch adds a simple ARP table in Slirp and also adds handling of
gratuitous ARP requests.
Signed-off-by: Fabien Chouteau <chouteau@adacore.com>
---
Makefile.objs | 2 +-
slirp/arp_table.c | 72 +++++++++++++++++++++++++++++++++++++++++++++++++++++
slirp/bootp.c | 21 +++++++++------
slirp/slirp.c | 63 +++++++++++----------------------------------
slirp/slirp.h | 47 ++++++++++++++++++++++++++++++++--
5 files changed, 146 insertions(+), 59 deletions(-)
create mode 100644 slirp/arp_table.c
diff --git a/Makefile.objs b/Makefile.objs
index 6991a9f..0c10557 100644
--- a/Makefile.objs
+++ b/Makefile.objs
@@ -151,7 +151,7 @@ common-obj-y += qemu-timer.o qemu-timer-common.o
slirp-obj-y = cksum.o if.o ip_icmp.o ip_input.o ip_output.o
slirp-obj-y += slirp.o mbuf.o misc.o sbuf.o socket.o tcp_input.o tcp_output.o
-slirp-obj-y += tcp_subr.o tcp_timer.o udp.o bootp.o tftp.o
+slirp-obj-y += tcp_subr.o tcp_timer.o udp.o bootp.o tftp.o arp_table.o
common-obj-$(CONFIG_SLIRP) += $(addprefix slirp/, $(slirp-obj-y))
# xen backend driver support
diff --git a/slirp/arp_table.c b/slirp/arp_table.c
new file mode 100644
index 0000000..c7034ee
--- /dev/null
+++ b/slirp/arp_table.c
@@ -0,0 +1,72 @@
+#include "slirp.h"
+
+void arp_table_add(Slirp *slirp, int ip_addr, uint8_t ethaddr[ETH_ALEN])
+{
+ const in_addr_t broadcast_addr =
+ ~slirp->vnetwork_mask.s_addr | slirp->vnetwork_addr.s_addr;
+ ArpTable *arptbl = &slirp->arp_table;
+ int i;
+
+ DEBUG_CALL("arp_table_add");
+ DEBUG_ARG("ip = 0x%x", ip_addr);
+ DEBUG_ARGS((dfd, " hw addr = %02x:%02x:%02x:%02x:%02x:%02x\n",
+ ethaddr[0], ethaddr[1], ethaddr[2],
+ ethaddr[3], ethaddr[4], ethaddr[5]));
+
+ if ((ip_addr & ~(0xf << 28)) == 0 ||
+ ip_addr == broadcast_addr) {
+ /* Do not register 0.0.0.0/8 or broadcast addresses */
+ return;
+ }
+
+ /* Search for an entry */
+ for (i = 0; i < ARP_TABLE_SIZE && arptbl->table[i].ar_sip != 0; i++) {
+ if (arptbl->table[i].ar_sip == ip_addr) {
+ /* Update the entry */
+ memcpy(arptbl->table[i].ar_sha, ethaddr, ETH_ALEN);
+ return;
+ }
+ }
+
+ /* No entry found, create a new one */
+ arptbl->table[arptbl->next_victim].ar_sip = ip_addr;
+ memcpy(arptbl->table[arptbl->next_victim].ar_sha, ethaddr, ETH_ALEN);
+ arptbl->next_victim = (arptbl->next_victim + 1) % ARP_TABLE_SIZE;
+}
+
+bool arp_table_search(Slirp *slirp, int in_ip_addr,
+ uint8_t out_ethaddr[ETH_ALEN])
+{
+ const in_addr_t broadcast_addr =
+ ~slirp->vnetwork_mask.s_addr | slirp->vnetwork_addr.s_addr;
+ ArpTable *arptbl = &slirp->arp_table;
+ int i;
+
+ DEBUG_CALL("arp_table_search");
+ DEBUG_ARG("ip = 0x%x", in_ip_addr);
+
+ /* If address in 0.0.0.0/8 */
+ if ((in_ip_addr & ~(0xf << 28)) == 0) {
+ /* Invalid address */
+ return 0;
+ }
+
+ /* If broadcast address */
+ if (in_ip_addr == broadcast_addr) {
+ /* return Ethernet broadcast address */
+ memset(out_ethaddr, 0xff, ETH_ALEN);
+ return 1;
+ }
+
+ for (i = 0; i < ARP_TABLE_SIZE; i++) {
+ if (arptbl->table[i].ar_sip == in_ip_addr) {
+ memcpy(out_ethaddr, arptbl->table[i].ar_sha, ETH_ALEN);
+ DEBUG_ARGS((dfd, " found hw addr = %02x:%02x:%02x:%02x:%02x:%02x\n",
+ out_ethaddr[0], out_ethaddr[1], out_ethaddr[2],
+ out_ethaddr[3], out_ethaddr[4], out_ethaddr[5]));
+ return 1;
+ }
+ }
+
+ return 0;
+}
diff --git a/slirp/bootp.c b/slirp/bootp.c
index 1eb2ed1..efd1fe7 100644
--- a/slirp/bootp.c
+++ b/slirp/bootp.c
@@ -149,6 +149,7 @@ static void bootp_reply(Slirp *slirp, const struct bootp_t *bp)
struct in_addr preq_addr;
int dhcp_msg_type, val;
uint8_t *q;
+ uint8_t client_ethaddr[ETH_ALEN];
/* extract exact DHCP msg type */
dhcp_decode(bp, &dhcp_msg_type, &preq_addr);
@@ -164,8 +165,9 @@ static void bootp_reply(Slirp *slirp, const struct bootp_t *bp)
if (dhcp_msg_type != DHCPDISCOVER &&
dhcp_msg_type != DHCPREQUEST)
return;
- /* XXX: this is a hack to get the client mac address */
- memcpy(slirp->client_ethaddr, bp->bp_hwaddr, 6);
+
+ /* Get client's hardware address from bootp request */
+ memcpy(client_ethaddr, bp->bp_hwaddr, ETH_ALEN);
m = m_get(slirp);
if (!m) {
@@ -178,25 +180,25 @@ static void bootp_reply(Slirp *slirp, const struct bootp_t *bp)
if (dhcp_msg_type == DHCPDISCOVER) {
if (preq_addr.s_addr != htonl(0L)) {
- bc = request_addr(slirp, &preq_addr, slirp->client_ethaddr);
+ bc = request_addr(slirp, &preq_addr, client_ethaddr);
if (bc) {
daddr.sin_addr = preq_addr;
}
}
if (!bc) {
new_addr:
- bc = get_new_addr(slirp, &daddr.sin_addr, slirp->client_ethaddr);
+ bc = get_new_addr(slirp, &daddr.sin_addr, client_ethaddr);
if (!bc) {
DPRINTF("no address left\n");
return;
}
}
- memcpy(bc->macaddr, slirp->client_ethaddr, 6);
+ memcpy(bc->macaddr, client_ethaddr, ETH_ALEN);
} else if (preq_addr.s_addr != htonl(0L)) {
- bc = request_addr(slirp, &preq_addr, slirp->client_ethaddr);
+ bc = request_addr(slirp, &preq_addr, client_ethaddr);
if (bc) {
daddr.sin_addr = preq_addr;
- memcpy(bc->macaddr, slirp->client_ethaddr, 6);
+ memcpy(bc->macaddr, client_ethaddr, ETH_ALEN);
} else {
daddr.sin_addr.s_addr = 0;
}
@@ -209,6 +211,9 @@ static void bootp_reply(Slirp *slirp, const struct bootp_t *bp)
}
}
+ /* Update ARP table for this IP address */
+ arp_table_add(slirp, daddr.sin_addr.s_addr, client_ethaddr);
+
saddr.sin_addr = slirp->vhost_addr;
saddr.sin_port = htons(BOOTP_SERVER);
@@ -218,7 +223,7 @@ static void bootp_reply(Slirp *slirp, const struct bootp_t *bp)
rbp->bp_xid = bp->bp_xid;
rbp->bp_htype = 1;
rbp->bp_hlen = 6;
- memcpy(rbp->bp_hwaddr, bp->bp_hwaddr, 6);
+ memcpy(rbp->bp_hwaddr, bp->bp_hwaddr, ETH_ALEN);
rbp->bp_yiaddr = daddr.sin_addr; /* Client IP address */
rbp->bp_siaddr = saddr.sin_addr; /* Server IP address */
diff --git a/slirp/slirp.c b/slirp/slirp.c
index df787ea..4a9a4d5 100644
--- a/slirp/slirp.c
+++ b/slirp/slirp.c
@@ -31,11 +31,11 @@
struct in_addr loopback_addr;
/* emulated hosts use the MAC addr 52:55:IP:IP:IP:IP */
-static const uint8_t special_ethaddr[6] = {
+static const uint8_t special_ethaddr[ETH_ALEN] = {
0x52, 0x55, 0x00, 0x00, 0x00, 0x00
};
-static const uint8_t zero_ethaddr[6] = { 0, 0, 0, 0, 0, 0 };
+static const uint8_t zero_ethaddr[ETH_ALEN] = { 0, 0, 0, 0, 0, 0 };
/* XXX: suppress those select globals */
fd_set *global_readfds, *global_writefds, *global_xfds;
@@ -599,42 +599,8 @@ void slirp_select_poll(fd_set *readfds, fd_set *writefds, fd_set *xfds,
global_xfds = NULL;
}
-#define ETH_ALEN 6
-#define ETH_HLEN 14
-
-#define ETH_P_IP 0x0800 /* Internet Protocol packet */
-#define ETH_P_ARP 0x0806 /* Address Resolution packet */
-
-#define ARPOP_REQUEST 1 /* ARP request */
-#define ARPOP_REPLY 2 /* ARP reply */
-
-struct ethhdr
-{
- unsigned char h_dest[ETH_ALEN]; /* destination eth addr */
- unsigned char h_source[ETH_ALEN]; /* source ether addr */
- unsigned short h_proto; /* packet type ID field */
-};
-
-struct arphdr
-{
- unsigned short ar_hrd; /* format of hardware address */
- unsigned short ar_pro; /* format of protocol address */
- unsigned char ar_hln; /* length of hardware address */
- unsigned char ar_pln; /* length of protocol address */
- unsigned short ar_op; /* ARP opcode (command) */
-
- /*
- * Ethernet looks like this : This bit is variable sized however...
- */
- unsigned char ar_sha[ETH_ALEN]; /* sender hardware address */
- uint32_t ar_sip; /* sender IP address */
- unsigned char ar_tha[ETH_ALEN]; /* target hardware address */
- uint32_t ar_tip ; /* target IP address */
-} __attribute__((packed));
-
static void arp_input(Slirp *slirp, const uint8_t *pkt, int pkt_len)
{
- struct ethhdr *eh = (struct ethhdr *)pkt;
struct arphdr *ah = (struct arphdr *)(pkt + ETH_HLEN);
uint8_t arp_reply[max(ETH_HLEN + sizeof(struct arphdr), 64)];
struct ethhdr *reh = (struct ethhdr *)arp_reply;
@@ -645,6 +611,12 @@ static void arp_input(Slirp *slirp, const uint8_t *pkt, int pkt_len)
ar_op = ntohs(ah->ar_op);
switch(ar_op) {
case ARPOP_REQUEST:
+ if (ah->ar_tip == ah->ar_sip) {
+ /* Gratuitous ARP */
+ arp_table_add(slirp, ah->ar_sip, ah->ar_sha);
+ return;
+ }
+
if ((ah->ar_tip & slirp->vnetwork_mask.s_addr) ==
slirp->vnetwork_addr.s_addr) {
if (ah->ar_tip == slirp->vnameserver_addr.s_addr ||
@@ -657,8 +629,8 @@ static void arp_input(Slirp *slirp, const uint8_t *pkt, int pkt_len)
return;
arp_ok:
memset(arp_reply, 0, sizeof(arp_reply));
- /* XXX: make an ARP request to have the client address */
- memcpy(slirp->client_ethaddr, eh->h_source, ETH_ALEN);
+
+ arp_table_add(slirp, ah->ar_sip, ah->ar_sha);
/* ARP request for alias/dns mac address */
memcpy(reh->h_dest, pkt + ETH_ALEN, ETH_ALEN);
@@ -679,11 +651,7 @@ static void arp_input(Slirp *slirp, const uint8_t *pkt, int pkt_len)
}
break;
case ARPOP_REPLY:
- /* reply to request of client mac address ? */
- if (!memcmp(slirp->client_ethaddr, zero_ethaddr, ETH_ALEN) &&
- ah->ar_sip == slirp->client_ipaddr.s_addr) {
- memcpy(slirp->client_ethaddr, ah->ar_sha, ETH_ALEN);
- }
+ arp_table_add(slirp, ah->ar_sip, ah->ar_sha);
break;
default:
break;
@@ -729,15 +697,16 @@ void if_encap(Slirp *slirp, const uint8_t *ip_data, int ip_data_len)
{
uint8_t buf[1600];
struct ethhdr *eh = (struct ethhdr *)buf;
+ uint8_t ethaddr[ETH_ALEN];
+ const struct ip *iph = (const struct ip *)ip_data;
if (ip_data_len + ETH_HLEN > sizeof(buf))
return;
-
- if (!memcmp(slirp->client_ethaddr, zero_ethaddr, ETH_ALEN)) {
+
+ if (!arp_table_search(slirp, iph->ip_dst.s_addr, ethaddr)) {
uint8_t arp_req[ETH_HLEN + sizeof(struct arphdr)];
struct ethhdr *reh = (struct ethhdr *)arp_req;
struct arphdr *rah = (struct arphdr *)(arp_req + ETH_HLEN);
- const struct ip *iph = (const struct ip *)ip_data;
/* If the client addr is not known, there is no point in
sending the packet to it. Normally the sender should have
@@ -765,7 +734,7 @@ void if_encap(Slirp *slirp, const uint8_t *ip_data, int ip_data_len)
slirp->client_ipaddr = iph->ip_dst;
slirp_output(slirp->opaque, arp_req, sizeof(arp_req));
} else {
- memcpy(eh->h_dest, slirp->client_ethaddr, ETH_ALEN);
+ memcpy(eh->h_dest, ethaddr, ETH_ALEN);
memcpy(eh->h_source, special_ethaddr, ETH_ALEN - 4);
/* XXX: not correct */
memcpy(&eh->h_source[2], &slirp->vhost_addr, 4);
diff --git a/slirp/slirp.h b/slirp/slirp.h
index 16bb6ba..2a070e6 100644
--- a/slirp/slirp.h
+++ b/slirp/slirp.h
@@ -170,6 +170,48 @@ int inet_aton(const char *cp, struct in_addr *ia);
/* osdep.c */
int qemu_socket(int domain, int type, int protocol);
+#define ETH_ALEN 6
+#define ETH_HLEN 14
+
+#define ETH_P_IP 0x0800 /* Internet Protocol packet */
+#define ETH_P_ARP 0x0806 /* Address Resolution packet */
+
+#define ARPOP_REQUEST 1 /* ARP request */
+#define ARPOP_REPLY 2 /* ARP reply */
+
+struct ethhdr {
+ unsigned char h_dest[ETH_ALEN]; /* destination eth addr */
+ unsigned char h_source[ETH_ALEN]; /* source ether addr */
+ unsigned short h_proto; /* packet type ID field */
+};
+
+struct arphdr {
+ unsigned short ar_hrd; /* format of hardware address */
+ unsigned short ar_pro; /* format of protocol address */
+ unsigned char ar_hln; /* length of hardware address */
+ unsigned char ar_pln; /* length of protocol address */
+ unsigned short ar_op; /* ARP opcode (command) */
+
+ /*
+ * Ethernet looks like this : This bit is variable sized however...
+ */
+ unsigned char ar_sha[ETH_ALEN]; /* sender hardware address */
+ uint32_t ar_sip; /* sender IP address */
+ unsigned char ar_tha[ETH_ALEN]; /* target hardware address */
+ uint32_t ar_tip; /* target IP address */
+} __attribute__((packed));
+
+#define ARP_TABLE_SIZE 16
+
+typedef struct ArpTable {
+ struct arphdr table[ARP_TABLE_SIZE];
+ int next_victim;
+} ArpTable;
+
+void arp_table_add(Slirp *slirp, int ip_addr, uint8_t ethaddr[ETH_ALEN]);
+
+bool arp_table_search(Slirp *slirp, int in_ip_addr,
+ uint8_t out_ethaddr[ETH_ALEN]);
struct Slirp {
QTAILQ_ENTRY(Slirp) entry;
@@ -181,9 +223,6 @@ struct Slirp {
struct in_addr vdhcp_startaddr;
struct in_addr vnameserver_addr;
- /* ARP cache for the guest IP addresses (XXX: allow many entries) */
- uint8_t client_ethaddr[6];
-
struct in_addr client_ipaddr;
char client_hostname[33];
@@ -227,6 +266,8 @@ struct Slirp {
char *tftp_prefix;
struct tftp_session tftp_sessions[TFTP_SESSIONS_MAX];
+ ArpTable arp_table;
+
void *opaque;
};
--
1.7.4.1
^ permalink raw reply related [flat|nested] 8+ messages in thread
* [Qemu-devel] [PATCH V3 2/2] [SLIRP] Delayed IP packets
2011-08-01 16:18 [Qemu-devel] [PATCH V3 1/2] [SLIRP] Simple ARP table Fabien Chouteau
@ 2011-08-01 16:18 ` Fabien Chouteau
2011-08-01 20:16 ` [Qemu-devel] [PATCH V3 1/2] [SLIRP] Simple ARP table Jan Kiszka
1 sibling, 0 replies; 8+ messages in thread
From: Fabien Chouteau @ 2011-08-01 16:18 UTC (permalink / raw)
To: qemu-devel; +Cc: jan.kiszka
In the current implementation, if Slirp tries to send an IP packet to a client
with an unknown hardware address, the packet is simply dropped and an ARP
request is sent (if_encap in slirp/slirp.c).
With this patch, Slirp will send the ARP request, re-queue the packet and try
to send it later. The packet is dropped after one second if the ARP reply is
not received.
Signed-off-by: Fabien Chouteau <chouteau@adacore.com>
---
slirp/if.c | 28 +++++++++++++++++++---
slirp/main.h | 2 +-
slirp/mbuf.c | 2 +
slirp/mbuf.h | 2 +
slirp/slirp.c | 72 +++++++++++++++++++++++++++++++-------------------------
5 files changed, 69 insertions(+), 37 deletions(-)
diff --git a/slirp/if.c b/slirp/if.c
index 0f04e13..2d79e45 100644
--- a/slirp/if.c
+++ b/slirp/if.c
@@ -6,6 +6,7 @@
*/
#include <slirp.h>
+#include "qemu-timer.h"
#define ifs_init(ifm) ((ifm)->ifs_next = (ifm)->ifs_prev = (ifm))
@@ -105,6 +106,9 @@ if_output(struct socket *so, struct mbuf *ifm)
ifs_init(ifm);
insque(ifm, ifq);
+ /* Expiration date = Now + 1 second */
+ ifm->expiration_date = qemu_get_clock_ns(rt_clock) + 1000000000ULL;
+
diddit:
slirp->if_queued++;
@@ -153,6 +157,9 @@ diddit:
void
if_start(Slirp *slirp)
{
+ int requeued = 0;
+ uint64_t now;
+
struct mbuf *ifm, *ifqt;
DEBUG_CALL("if_start");
@@ -165,6 +172,8 @@ if_start(Slirp *slirp)
if (!slirp_can_output(slirp->opaque))
return;
+ now = qemu_get_clock_ns(rt_clock);
+
/*
* See which queue to get next packet from
* If there's something in the fastq, select it immediately
@@ -199,11 +208,22 @@ if_start(Slirp *slirp)
ifm->ifq_so->so_nqueued = 0;
}
- /* Encapsulate the packet for sending */
- if_encap(slirp, (uint8_t *)ifm->m_data, ifm->m_len);
-
- m_free(ifm);
+ if (ifm->expiration_date < now) {
+ /* Expired */
+ m_free(ifm);
+ } else {
+ /* Encapsulate the packet for sending */
+ if (if_encap(slirp, ifm)) {
+ m_free(ifm);
+ } else {
+ /* re-queue */
+ insque(ifm, ifqt);
+ requeued++;
+ }
+ }
if (slirp->if_queued)
goto again;
+
+ slirp->if_queued = requeued;
}
diff --git a/slirp/main.h b/slirp/main.h
index 0dd8d81..028df4b 100644
--- a/slirp/main.h
+++ b/slirp/main.h
@@ -42,5 +42,5 @@ extern int tcp_keepintvl;
#define PROTO_PPP 0x2
#endif
-void if_encap(Slirp *slirp, const uint8_t *ip_data, int ip_data_len);
+int if_encap(Slirp *slirp, struct mbuf *ifm);
ssize_t slirp_send(struct socket *so, const void *buf, size_t len, int flags);
diff --git a/slirp/mbuf.c b/slirp/mbuf.c
index ce2eb84..c699c75 100644
--- a/slirp/mbuf.c
+++ b/slirp/mbuf.c
@@ -70,6 +70,8 @@ m_get(Slirp *slirp)
m->m_len = 0;
m->m_nextpkt = NULL;
m->m_prevpkt = NULL;
+ m->arp_requested = false;
+ m->expiration_date = (uint64_t)-1;
end_error:
DEBUG_ARG("m = %lx", (long )m);
return m;
diff --git a/slirp/mbuf.h b/slirp/mbuf.h
index b74544b..55170e5 100644
--- a/slirp/mbuf.h
+++ b/slirp/mbuf.h
@@ -86,6 +86,8 @@ struct mbuf {
char m_dat_[1]; /* ANSI don't like 0 sized arrays */
char *m_ext_;
} M_dat;
+ bool arp_requested;
+ uint64_t expiration_date;
};
#define m_next m_hdr.mh_next
diff --git a/slirp/slirp.c b/slirp/slirp.c
index 4a9a4d5..a86cc6e 100644
--- a/slirp/slirp.c
+++ b/slirp/slirp.c
@@ -692,55 +692,63 @@ void slirp_input(Slirp *slirp, const uint8_t *pkt, int pkt_len)
}
}
-/* output the IP packet to the ethernet device */
-void if_encap(Slirp *slirp, const uint8_t *ip_data, int ip_data_len)
+/* Output the IP packet to the ethernet device. Returns 0 if the packet must be
+ * re-queued.
+ */
+int if_encap(Slirp *slirp, struct mbuf *ifm)
{
uint8_t buf[1600];
struct ethhdr *eh = (struct ethhdr *)buf;
uint8_t ethaddr[ETH_ALEN];
- const struct ip *iph = (const struct ip *)ip_data;
+ const struct ip *iph = (const struct ip *)ifm->m_data;
- if (ip_data_len + ETH_HLEN > sizeof(buf))
- return;
+ if (ifm->m_len + ETH_HLEN > sizeof(buf)) {
+ return 1;
+ }
if (!arp_table_search(slirp, iph->ip_dst.s_addr, ethaddr)) {
uint8_t arp_req[ETH_HLEN + sizeof(struct arphdr)];
struct ethhdr *reh = (struct ethhdr *)arp_req;
struct arphdr *rah = (struct arphdr *)(arp_req + ETH_HLEN);
- /* If the client addr is not known, there is no point in
- sending the packet to it. Normally the sender should have
- done an ARP request to get its MAC address. Here we do it
- in place of sending the packet and we hope that the sender
- will retry sending its packet. */
- memset(reh->h_dest, 0xff, ETH_ALEN);
- memcpy(reh->h_source, special_ethaddr, ETH_ALEN - 4);
- memcpy(&reh->h_source[2], &slirp->vhost_addr, 4);
- reh->h_proto = htons(ETH_P_ARP);
- rah->ar_hrd = htons(1);
- rah->ar_pro = htons(ETH_P_IP);
- rah->ar_hln = ETH_ALEN;
- rah->ar_pln = 4;
- rah->ar_op = htons(ARPOP_REQUEST);
- /* source hw addr */
- memcpy(rah->ar_sha, special_ethaddr, ETH_ALEN - 4);
- memcpy(&rah->ar_sha[2], &slirp->vhost_addr, 4);
- /* source IP */
- rah->ar_sip = slirp->vhost_addr.s_addr;
- /* target hw addr (none) */
- memset(rah->ar_tha, 0, ETH_ALEN);
- /* target IP */
- rah->ar_tip = iph->ip_dst.s_addr;
- slirp->client_ipaddr = iph->ip_dst;
- slirp_output(slirp->opaque, arp_req, sizeof(arp_req));
+ if (!ifm->arp_requested) {
+ /* If the client addr is not known, send an ARP request */
+ memset(reh->h_dest, 0xff, ETH_ALEN);
+ memcpy(reh->h_source, special_ethaddr, ETH_ALEN - 4);
+ memcpy(&reh->h_source[2], &slirp->vhost_addr, 4);
+ reh->h_proto = htons(ETH_P_ARP);
+ rah->ar_hrd = htons(1);
+ rah->ar_pro = htons(ETH_P_IP);
+ rah->ar_hln = ETH_ALEN;
+ rah->ar_pln = 4;
+ rah->ar_op = htons(ARPOP_REQUEST);
+
+ /* source hw addr */
+ memcpy(rah->ar_sha, special_ethaddr, ETH_ALEN - 4);
+ memcpy(&rah->ar_sha[2], &slirp->vhost_addr, 4);
+
+ /* source IP */
+ rah->ar_sip = slirp->vhost_addr.s_addr;
+
+ /* target hw addr (none) */
+ memset(rah->ar_tha, 0, ETH_ALEN);
+
+ /* target IP */
+ rah->ar_tip = iph->ip_dst.s_addr;
+ slirp->client_ipaddr = iph->ip_dst;
+ slirp_output(slirp->opaque, arp_req, sizeof(arp_req));
+ ifm->arp_requested = true;
+ }
+ return 0;
} else {
memcpy(eh->h_dest, ethaddr, ETH_ALEN);
memcpy(eh->h_source, special_ethaddr, ETH_ALEN - 4);
/* XXX: not correct */
memcpy(&eh->h_source[2], &slirp->vhost_addr, 4);
eh->h_proto = htons(ETH_P_IP);
- memcpy(buf + sizeof(struct ethhdr), ip_data, ip_data_len);
- slirp_output(slirp->opaque, buf, ip_data_len + ETH_HLEN);
+ memcpy(buf + sizeof(struct ethhdr), ifm->m_data, ifm->m_len);
+ slirp_output(slirp->opaque, buf, ifm->m_len + ETH_HLEN);
+ return 1;
}
}
--
1.7.4.1
^ permalink raw reply related [flat|nested] 8+ messages in thread
* Re: [Qemu-devel] [PATCH V3 1/2] [SLIRP] Simple ARP table
2011-08-01 16:18 [Qemu-devel] [PATCH V3 1/2] [SLIRP] Simple ARP table Fabien Chouteau
2011-08-01 16:18 ` [Qemu-devel] [PATCH V3 2/2] [SLIRP] Delayed IP packets Fabien Chouteau
@ 2011-08-01 20:16 ` Jan Kiszka
2011-08-02 9:58 ` Fabien Chouteau
2011-08-02 13:19 ` [Qemu-devel] [PATCH V4 " Fabien Chouteau
1 sibling, 2 replies; 8+ messages in thread
From: Jan Kiszka @ 2011-08-01 20:16 UTC (permalink / raw)
To: Fabien Chouteau; +Cc: qemu-devel
[-- Attachment #1: Type: text/plain, Size: 3582 bytes --]
On 2011-08-01 18:18, Fabien Chouteau wrote:
> This patch adds a simple ARP table in Slirp and also adds handling of
> gratuitous ARP requests.
>
> Signed-off-by: Fabien Chouteau <chouteau@adacore.com>
> ---
> Makefile.objs | 2 +-
> slirp/arp_table.c | 72 +++++++++++++++++++++++++++++++++++++++++++++++++++++
> slirp/bootp.c | 21 +++++++++------
> slirp/slirp.c | 63 +++++++++++----------------------------------
> slirp/slirp.h | 47 ++++++++++++++++++++++++++++++++--
> 5 files changed, 146 insertions(+), 59 deletions(-)
> create mode 100644 slirp/arp_table.c
>
> diff --git a/Makefile.objs b/Makefile.objs
> index 6991a9f..0c10557 100644
> --- a/Makefile.objs
> +++ b/Makefile.objs
> @@ -151,7 +151,7 @@ common-obj-y += qemu-timer.o qemu-timer-common.o
>
> slirp-obj-y = cksum.o if.o ip_icmp.o ip_input.o ip_output.o
> slirp-obj-y += slirp.o mbuf.o misc.o sbuf.o socket.o tcp_input.o tcp_output.o
> -slirp-obj-y += tcp_subr.o tcp_timer.o udp.o bootp.o tftp.o
> +slirp-obj-y += tcp_subr.o tcp_timer.o udp.o bootp.o tftp.o arp_table.o
> common-obj-$(CONFIG_SLIRP) += $(addprefix slirp/, $(slirp-obj-y))
>
> # xen backend driver support
> diff --git a/slirp/arp_table.c b/slirp/arp_table.c
> new file mode 100644
> index 0000000..c7034ee
> --- /dev/null
> +++ b/slirp/arp_table.c
> @@ -0,0 +1,72 @@
> +#include "slirp.h"
> +
> +void arp_table_add(Slirp *slirp, int ip_addr, uint8_t ethaddr[ETH_ALEN])
> +{
> + const in_addr_t broadcast_addr =
> + ~slirp->vnetwork_mask.s_addr | slirp->vnetwork_addr.s_addr;
That's only part of the picture. 255.255.255.255 is a valid broadcast
address as well.
> + ArpTable *arptbl = &slirp->arp_table;
> + int i;
> +
> + DEBUG_CALL("arp_table_add");
> + DEBUG_ARG("ip = 0x%x", ip_addr);
> + DEBUG_ARGS((dfd, " hw addr = %02x:%02x:%02x:%02x:%02x:%02x\n",
> + ethaddr[0], ethaddr[1], ethaddr[2],
> + ethaddr[3], ethaddr[4], ethaddr[5]));
> +
> + if ((ip_addr & ~(0xf << 28)) == 0 ||
> + ip_addr == broadcast_addr) {
> + /* Do not register 0.0.0.0/8 or broadcast addresses */
> + return;
> + }
> +
> + /* Search for an entry */
> + for (i = 0; i < ARP_TABLE_SIZE && arptbl->table[i].ar_sip != 0; i++) {
Forgot to remove the test for ar_sip != 0.
> + if (arptbl->table[i].ar_sip == ip_addr) {
> + /* Update the entry */
> + memcpy(arptbl->table[i].ar_sha, ethaddr, ETH_ALEN);
> + return;
> + }
> + }
> +
> + /* No entry found, create a new one */
> + arptbl->table[arptbl->next_victim].ar_sip = ip_addr;
> + memcpy(arptbl->table[arptbl->next_victim].ar_sha, ethaddr, ETH_ALEN);
> + arptbl->next_victim = (arptbl->next_victim + 1) % ARP_TABLE_SIZE;
> +}
> +
> +bool arp_table_search(Slirp *slirp, int in_ip_addr,
> + uint8_t out_ethaddr[ETH_ALEN])
> +{
> + const in_addr_t broadcast_addr =
> + ~slirp->vnetwork_mask.s_addr | slirp->vnetwork_addr.s_addr;
Same as above. That means DCHP is still broken. Please include that
scenario in your tests before sending the next round.
> + ArpTable *arptbl = &slirp->arp_table;
> + int i;
> +
> + DEBUG_CALL("arp_table_search");
> + DEBUG_ARG("ip = 0x%x", in_ip_addr);
> +
> + /* If address in 0.0.0.0/8 */
> + if ((in_ip_addr & ~(0xf << 28)) == 0) {
Should rather be an assert() as it means the caller is about to send a
frame to that source-only address.
Jan
[-- Attachment #2: OpenPGP digital signature --]
[-- Type: application/pgp-signature, Size: 262 bytes --]
^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: [Qemu-devel] [PATCH V3 1/2] [SLIRP] Simple ARP table
2011-08-01 20:16 ` [Qemu-devel] [PATCH V3 1/2] [SLIRP] Simple ARP table Jan Kiszka
@ 2011-08-02 9:58 ` Fabien Chouteau
2011-08-02 13:19 ` [Qemu-devel] [PATCH V4 " Fabien Chouteau
1 sibling, 0 replies; 8+ messages in thread
From: Fabien Chouteau @ 2011-08-02 9:58 UTC (permalink / raw)
To: Jan Kiszka; +Cc: qemu-devel
On 01/08/2011 22:16, Jan Kiszka wrote:
> On 2011-08-01 18:18, Fabien Chouteau wrote:
>> This patch adds a simple ARP table in Slirp and also adds handling of
>> gratuitous ARP requests.
>>
>> Signed-off-by: Fabien Chouteau <chouteau@adacore.com>
>> ---
>> Makefile.objs | 2 +-
>> slirp/arp_table.c | 72 +++++++++++++++++++++++++++++++++++++++++++++++++++++
>> slirp/bootp.c | 21 +++++++++------
>> slirp/slirp.c | 63 +++++++++++----------------------------------
>> slirp/slirp.h | 47 ++++++++++++++++++++++++++++++++--
>> 5 files changed, 146 insertions(+), 59 deletions(-)
>> create mode 100644 slirp/arp_table.c
>>
>> diff --git a/Makefile.objs b/Makefile.objs
>> index 6991a9f..0c10557 100644
>> --- a/Makefile.objs
>> +++ b/Makefile.objs
>> @@ -151,7 +151,7 @@ common-obj-y += qemu-timer.o qemu-timer-common.o
>>
>> slirp-obj-y = cksum.o if.o ip_icmp.o ip_input.o ip_output.o
>> slirp-obj-y += slirp.o mbuf.o misc.o sbuf.o socket.o tcp_input.o tcp_output.o
>> -slirp-obj-y += tcp_subr.o tcp_timer.o udp.o bootp.o tftp.o
>> +slirp-obj-y += tcp_subr.o tcp_timer.o udp.o bootp.o tftp.o arp_table.o
>> common-obj-$(CONFIG_SLIRP) += $(addprefix slirp/, $(slirp-obj-y))
>>
>> # xen backend driver support
>> diff --git a/slirp/arp_table.c b/slirp/arp_table.c
>> new file mode 100644
>> index 0000000..c7034ee
>> --- /dev/null
>> +++ b/slirp/arp_table.c
>> @@ -0,0 +1,72 @@
>> +#include "slirp.h"
>> +
>> +void arp_table_add(Slirp *slirp, int ip_addr, uint8_t ethaddr[ETH_ALEN])
>> +{
>> + const in_addr_t broadcast_addr =
>> + ~slirp->vnetwork_mask.s_addr | slirp->vnetwork_addr.s_addr;
>
> That's only part of the picture. 255.255.255.255 is a valid broadcast
> address as well.
Of course, how can I have missed this...
>> + ArpTable *arptbl = &slirp->arp_table;
>> + int i;
>> +
>> + DEBUG_CALL("arp_table_add");
>> + DEBUG_ARG("ip = 0x%x", ip_addr);
>> + DEBUG_ARGS((dfd, " hw addr = %02x:%02x:%02x:%02x:%02x:%02x\n",
>> + ethaddr[0], ethaddr[1], ethaddr[2],
>> + ethaddr[3], ethaddr[4], ethaddr[5]));
>> +
>> + if ((ip_addr & ~(0xf << 28)) == 0 ||
>> + ip_addr == broadcast_addr) {
>> + /* Do not register 0.0.0.0/8 or broadcast addresses */
>> + return;
>> + }
>> +
>> + /* Search for an entry */
>> + for (i = 0; i < ARP_TABLE_SIZE && arptbl->table[i].ar_sip != 0; i++) {
>
> Forgot to remove the test for ar_sip != 0.
>
>> + if (arptbl->table[i].ar_sip == ip_addr) {
>> + /* Update the entry */
>> + memcpy(arptbl->table[i].ar_sha, ethaddr, ETH_ALEN);
>> + return;
>> + }
>> + }
>> +
>> + /* No entry found, create a new one */
>> + arptbl->table[arptbl->next_victim].ar_sip = ip_addr;
>> + memcpy(arptbl->table[arptbl->next_victim].ar_sha, ethaddr, ETH_ALEN);
>> + arptbl->next_victim = (arptbl->next_victim + 1) % ARP_TABLE_SIZE;
>> +}
>> +
>> +bool arp_table_search(Slirp *slirp, int in_ip_addr,
>> + uint8_t out_ethaddr[ETH_ALEN])
>> +{
>> + const in_addr_t broadcast_addr =
>> + ~slirp->vnetwork_mask.s_addr | slirp->vnetwork_addr.s_addr;
>
> Same as above. That means DCHP is still broken. Please include that
> scenario in your tests before sending the next round.
OK I will test with DHCP.
Thanks again,
--
Fabien Chouteau
^ permalink raw reply [flat|nested] 8+ messages in thread
* [Qemu-devel] [PATCH V4 1/2] [SLIRP] Simple ARP table
2011-08-01 20:16 ` [Qemu-devel] [PATCH V3 1/2] [SLIRP] Simple ARP table Jan Kiszka
2011-08-02 9:58 ` Fabien Chouteau
@ 2011-08-02 13:19 ` Fabien Chouteau
2011-08-03 9:13 ` Jan Kiszka
1 sibling, 1 reply; 8+ messages in thread
From: Fabien Chouteau @ 2011-08-02 13:19 UTC (permalink / raw)
To: qemu-devel; +Cc: jan.kiszka
This patch adds a simple ARP table in Slirp and also adds handling of
gratuitous ARP requests.
Signed-off-by: Fabien Chouteau <chouteau@adacore.com>
---
Makefile.objs | 2 +-
slirp/arp_table.c | 71 +++++++++++++++++++++++++++++++++++++++++++++++++++++
slirp/bootp.c | 21 +++++++++------
slirp/slirp.c | 63 ++++++++++++-----------------------------------
slirp/slirp.h | 47 ++++++++++++++++++++++++++++++++--
5 files changed, 145 insertions(+), 59 deletions(-)
create mode 100644 slirp/arp_table.c
diff --git a/Makefile.objs b/Makefile.objs
index 6991a9f..0c10557 100644
--- a/Makefile.objs
+++ b/Makefile.objs
@@ -151,7 +151,7 @@ common-obj-y += qemu-timer.o qemu-timer-common.o
slirp-obj-y = cksum.o if.o ip_icmp.o ip_input.o ip_output.o
slirp-obj-y += slirp.o mbuf.o misc.o sbuf.o socket.o tcp_input.o tcp_output.o
-slirp-obj-y += tcp_subr.o tcp_timer.o udp.o bootp.o tftp.o
+slirp-obj-y += tcp_subr.o tcp_timer.o udp.o bootp.o tftp.o arp_table.o
common-obj-$(CONFIG_SLIRP) += $(addprefix slirp/, $(slirp-obj-y))
# xen backend driver support
diff --git a/slirp/arp_table.c b/slirp/arp_table.c
new file mode 100644
index 0000000..c259b42
--- /dev/null
+++ b/slirp/arp_table.c
@@ -0,0 +1,71 @@
+#include "slirp.h"
+
+void arp_table_add(Slirp *slirp, int ip_addr, uint8_t ethaddr[ETH_ALEN])
+{
+ const in_addr_t broadcast_addr =
+ ~slirp->vnetwork_mask.s_addr | slirp->vnetwork_addr.s_addr;
+ ArpTable *arptbl = &slirp->arp_table;
+ int i;
+
+ DEBUG_CALL("arp_table_add");
+ DEBUG_ARG("ip = 0x%x", ip_addr);
+ DEBUG_ARGS((dfd, " hw addr = %02x:%02x:%02x:%02x:%02x:%02x\n",
+ ethaddr[0], ethaddr[1], ethaddr[2],
+ ethaddr[3], ethaddr[4], ethaddr[5]));
+
+ /* Check 0.0.0.0/8 invalid source-only addresses */
+ assert((ip_addr & htonl(~(0xf << 28))) != 0);
+
+ if (ip_addr == 0xffffffff || ip_addr == broadcast_addr) {
+ /* Do not register broadcast addresses */
+ return;
+ }
+
+ /* Search for an entry */
+ for (i = 0; i < ARP_TABLE_SIZE; i++) {
+ if (arptbl->table[i].ar_sip == ip_addr) {
+ /* Update the entry */
+ memcpy(arptbl->table[i].ar_sha, ethaddr, ETH_ALEN);
+ return;
+ }
+ }
+
+ /* No entry found, create a new one */
+ arptbl->table[arptbl->next_victim].ar_sip = ip_addr;
+ memcpy(arptbl->table[arptbl->next_victim].ar_sha, ethaddr, ETH_ALEN);
+ arptbl->next_victim = (arptbl->next_victim + 1) % ARP_TABLE_SIZE;
+}
+
+bool arp_table_search(Slirp *slirp, int in_ip_addr,
+ uint8_t out_ethaddr[ETH_ALEN])
+{
+ const in_addr_t broadcast_addr =
+ ~slirp->vnetwork_mask.s_addr | slirp->vnetwork_addr.s_addr;
+ ArpTable *arptbl = &slirp->arp_table;
+ int i;
+
+ DEBUG_CALL("arp_table_search");
+ DEBUG_ARG("ip = 0x%x", in_ip_addr);
+
+ /* Check 0.0.0.0/8 invalid source-only addresses */
+ assert((in_ip_addr & htonl(~(0xf << 28))) != 0);
+
+ /* If broadcast address */
+ if (in_ip_addr == 0xffffffff || in_ip_addr == broadcast_addr) {
+ /* return Ethernet broadcast address */
+ memset(out_ethaddr, 0xff, ETH_ALEN);
+ return 1;
+ }
+
+ for (i = 0; i < ARP_TABLE_SIZE; i++) {
+ if (arptbl->table[i].ar_sip == in_ip_addr) {
+ memcpy(out_ethaddr, arptbl->table[i].ar_sha, ETH_ALEN);
+ DEBUG_ARGS((dfd, " found hw addr = %02x:%02x:%02x:%02x:%02x:%02x\n",
+ out_ethaddr[0], out_ethaddr[1], out_ethaddr[2],
+ out_ethaddr[3], out_ethaddr[4], out_ethaddr[5]));
+ return 1;
+ }
+ }
+
+ return 0;
+}
diff --git a/slirp/bootp.c b/slirp/bootp.c
index 1eb2ed1..efd1fe7 100644
--- a/slirp/bootp.c
+++ b/slirp/bootp.c
@@ -149,6 +149,7 @@ static void bootp_reply(Slirp *slirp, const struct bootp_t *bp)
struct in_addr preq_addr;
int dhcp_msg_type, val;
uint8_t *q;
+ uint8_t client_ethaddr[ETH_ALEN];
/* extract exact DHCP msg type */
dhcp_decode(bp, &dhcp_msg_type, &preq_addr);
@@ -164,8 +165,9 @@ static void bootp_reply(Slirp *slirp, const struct bootp_t *bp)
if (dhcp_msg_type != DHCPDISCOVER &&
dhcp_msg_type != DHCPREQUEST)
return;
- /* XXX: this is a hack to get the client mac address */
- memcpy(slirp->client_ethaddr, bp->bp_hwaddr, 6);
+
+ /* Get client's hardware address from bootp request */
+ memcpy(client_ethaddr, bp->bp_hwaddr, ETH_ALEN);
m = m_get(slirp);
if (!m) {
@@ -178,25 +180,25 @@ static void bootp_reply(Slirp *slirp, const struct bootp_t *bp)
if (dhcp_msg_type == DHCPDISCOVER) {
if (preq_addr.s_addr != htonl(0L)) {
- bc = request_addr(slirp, &preq_addr, slirp->client_ethaddr);
+ bc = request_addr(slirp, &preq_addr, client_ethaddr);
if (bc) {
daddr.sin_addr = preq_addr;
}
}
if (!bc) {
new_addr:
- bc = get_new_addr(slirp, &daddr.sin_addr, slirp->client_ethaddr);
+ bc = get_new_addr(slirp, &daddr.sin_addr, client_ethaddr);
if (!bc) {
DPRINTF("no address left\n");
return;
}
}
- memcpy(bc->macaddr, slirp->client_ethaddr, 6);
+ memcpy(bc->macaddr, client_ethaddr, ETH_ALEN);
} else if (preq_addr.s_addr != htonl(0L)) {
- bc = request_addr(slirp, &preq_addr, slirp->client_ethaddr);
+ bc = request_addr(slirp, &preq_addr, client_ethaddr);
if (bc) {
daddr.sin_addr = preq_addr;
- memcpy(bc->macaddr, slirp->client_ethaddr, 6);
+ memcpy(bc->macaddr, client_ethaddr, ETH_ALEN);
} else {
daddr.sin_addr.s_addr = 0;
}
@@ -209,6 +211,9 @@ static void bootp_reply(Slirp *slirp, const struct bootp_t *bp)
}
}
+ /* Update ARP table for this IP address */
+ arp_table_add(slirp, daddr.sin_addr.s_addr, client_ethaddr);
+
saddr.sin_addr = slirp->vhost_addr;
saddr.sin_port = htons(BOOTP_SERVER);
@@ -218,7 +223,7 @@ static void bootp_reply(Slirp *slirp, const struct bootp_t *bp)
rbp->bp_xid = bp->bp_xid;
rbp->bp_htype = 1;
rbp->bp_hlen = 6;
- memcpy(rbp->bp_hwaddr, bp->bp_hwaddr, 6);
+ memcpy(rbp->bp_hwaddr, bp->bp_hwaddr, ETH_ALEN);
rbp->bp_yiaddr = daddr.sin_addr; /* Client IP address */
rbp->bp_siaddr = saddr.sin_addr; /* Server IP address */
diff --git a/slirp/slirp.c b/slirp/slirp.c
index df787ea..4a9a4d5 100644
--- a/slirp/slirp.c
+++ b/slirp/slirp.c
@@ -31,11 +31,11 @@
struct in_addr loopback_addr;
/* emulated hosts use the MAC addr 52:55:IP:IP:IP:IP */
-static const uint8_t special_ethaddr[6] = {
+static const uint8_t special_ethaddr[ETH_ALEN] = {
0x52, 0x55, 0x00, 0x00, 0x00, 0x00
};
-static const uint8_t zero_ethaddr[6] = { 0, 0, 0, 0, 0, 0 };
+static const uint8_t zero_ethaddr[ETH_ALEN] = { 0, 0, 0, 0, 0, 0 };
/* XXX: suppress those select globals */
fd_set *global_readfds, *global_writefds, *global_xfds;
@@ -599,42 +599,8 @@ void slirp_select_poll(fd_set *readfds, fd_set *writefds, fd_set *xfds,
global_xfds = NULL;
}
-#define ETH_ALEN 6
-#define ETH_HLEN 14
-
-#define ETH_P_IP 0x0800 /* Internet Protocol packet */
-#define ETH_P_ARP 0x0806 /* Address Resolution packet */
-
-#define ARPOP_REQUEST 1 /* ARP request */
-#define ARPOP_REPLY 2 /* ARP reply */
-
-struct ethhdr
-{
- unsigned char h_dest[ETH_ALEN]; /* destination eth addr */
- unsigned char h_source[ETH_ALEN]; /* source ether addr */
- unsigned short h_proto; /* packet type ID field */
-};
-
-struct arphdr
-{
- unsigned short ar_hrd; /* format of hardware address */
- unsigned short ar_pro; /* format of protocol address */
- unsigned char ar_hln; /* length of hardware address */
- unsigned char ar_pln; /* length of protocol address */
- unsigned short ar_op; /* ARP opcode (command) */
-
- /*
- * Ethernet looks like this : This bit is variable sized however...
- */
- unsigned char ar_sha[ETH_ALEN]; /* sender hardware address */
- uint32_t ar_sip; /* sender IP address */
- unsigned char ar_tha[ETH_ALEN]; /* target hardware address */
- uint32_t ar_tip ; /* target IP address */
-} __attribute__((packed));
-
static void arp_input(Slirp *slirp, const uint8_t *pkt, int pkt_len)
{
- struct ethhdr *eh = (struct ethhdr *)pkt;
struct arphdr *ah = (struct arphdr *)(pkt + ETH_HLEN);
uint8_t arp_reply[max(ETH_HLEN + sizeof(struct arphdr), 64)];
struct ethhdr *reh = (struct ethhdr *)arp_reply;
@@ -645,6 +611,12 @@ static void arp_input(Slirp *slirp, const uint8_t *pkt, int pkt_len)
ar_op = ntohs(ah->ar_op);
switch(ar_op) {
case ARPOP_REQUEST:
+ if (ah->ar_tip == ah->ar_sip) {
+ /* Gratuitous ARP */
+ arp_table_add(slirp, ah->ar_sip, ah->ar_sha);
+ return;
+ }
+
if ((ah->ar_tip & slirp->vnetwork_mask.s_addr) ==
slirp->vnetwork_addr.s_addr) {
if (ah->ar_tip == slirp->vnameserver_addr.s_addr ||
@@ -657,8 +629,8 @@ static void arp_input(Slirp *slirp, const uint8_t *pkt, int pkt_len)
return;
arp_ok:
memset(arp_reply, 0, sizeof(arp_reply));
- /* XXX: make an ARP request to have the client address */
- memcpy(slirp->client_ethaddr, eh->h_source, ETH_ALEN);
+
+ arp_table_add(slirp, ah->ar_sip, ah->ar_sha);
/* ARP request for alias/dns mac address */
memcpy(reh->h_dest, pkt + ETH_ALEN, ETH_ALEN);
@@ -679,11 +651,7 @@ static void arp_input(Slirp *slirp, const uint8_t *pkt, int pkt_len)
}
break;
case ARPOP_REPLY:
- /* reply to request of client mac address ? */
- if (!memcmp(slirp->client_ethaddr, zero_ethaddr, ETH_ALEN) &&
- ah->ar_sip == slirp->client_ipaddr.s_addr) {
- memcpy(slirp->client_ethaddr, ah->ar_sha, ETH_ALEN);
- }
+ arp_table_add(slirp, ah->ar_sip, ah->ar_sha);
break;
default:
break;
@@ -729,15 +697,16 @@ void if_encap(Slirp *slirp, const uint8_t *ip_data, int ip_data_len)
{
uint8_t buf[1600];
struct ethhdr *eh = (struct ethhdr *)buf;
+ uint8_t ethaddr[ETH_ALEN];
+ const struct ip *iph = (const struct ip *)ip_data;
if (ip_data_len + ETH_HLEN > sizeof(buf))
return;
-
- if (!memcmp(slirp->client_ethaddr, zero_ethaddr, ETH_ALEN)) {
+
+ if (!arp_table_search(slirp, iph->ip_dst.s_addr, ethaddr)) {
uint8_t arp_req[ETH_HLEN + sizeof(struct arphdr)];
struct ethhdr *reh = (struct ethhdr *)arp_req;
struct arphdr *rah = (struct arphdr *)(arp_req + ETH_HLEN);
- const struct ip *iph = (const struct ip *)ip_data;
/* If the client addr is not known, there is no point in
sending the packet to it. Normally the sender should have
@@ -765,7 +734,7 @@ void if_encap(Slirp *slirp, const uint8_t *ip_data, int ip_data_len)
slirp->client_ipaddr = iph->ip_dst;
slirp_output(slirp->opaque, arp_req, sizeof(arp_req));
} else {
- memcpy(eh->h_dest, slirp->client_ethaddr, ETH_ALEN);
+ memcpy(eh->h_dest, ethaddr, ETH_ALEN);
memcpy(eh->h_source, special_ethaddr, ETH_ALEN - 4);
/* XXX: not correct */
memcpy(&eh->h_source[2], &slirp->vhost_addr, 4);
diff --git a/slirp/slirp.h b/slirp/slirp.h
index 16bb6ba..2a070e6 100644
--- a/slirp/slirp.h
+++ b/slirp/slirp.h
@@ -170,6 +170,48 @@ int inet_aton(const char *cp, struct in_addr *ia);
/* osdep.c */
int qemu_socket(int domain, int type, int protocol);
+#define ETH_ALEN 6
+#define ETH_HLEN 14
+
+#define ETH_P_IP 0x0800 /* Internet Protocol packet */
+#define ETH_P_ARP 0x0806 /* Address Resolution packet */
+
+#define ARPOP_REQUEST 1 /* ARP request */
+#define ARPOP_REPLY 2 /* ARP reply */
+
+struct ethhdr {
+ unsigned char h_dest[ETH_ALEN]; /* destination eth addr */
+ unsigned char h_source[ETH_ALEN]; /* source ether addr */
+ unsigned short h_proto; /* packet type ID field */
+};
+
+struct arphdr {
+ unsigned short ar_hrd; /* format of hardware address */
+ unsigned short ar_pro; /* format of protocol address */
+ unsigned char ar_hln; /* length of hardware address */
+ unsigned char ar_pln; /* length of protocol address */
+ unsigned short ar_op; /* ARP opcode (command) */
+
+ /*
+ * Ethernet looks like this : This bit is variable sized however...
+ */
+ unsigned char ar_sha[ETH_ALEN]; /* sender hardware address */
+ uint32_t ar_sip; /* sender IP address */
+ unsigned char ar_tha[ETH_ALEN]; /* target hardware address */
+ uint32_t ar_tip; /* target IP address */
+} __attribute__((packed));
+
+#define ARP_TABLE_SIZE 16
+
+typedef struct ArpTable {
+ struct arphdr table[ARP_TABLE_SIZE];
+ int next_victim;
+} ArpTable;
+
+void arp_table_add(Slirp *slirp, int ip_addr, uint8_t ethaddr[ETH_ALEN]);
+
+bool arp_table_search(Slirp *slirp, int in_ip_addr,
+ uint8_t out_ethaddr[ETH_ALEN]);
struct Slirp {
QTAILQ_ENTRY(Slirp) entry;
@@ -181,9 +223,6 @@ struct Slirp {
struct in_addr vdhcp_startaddr;
struct in_addr vnameserver_addr;
- /* ARP cache for the guest IP addresses (XXX: allow many entries) */
- uint8_t client_ethaddr[6];
-
struct in_addr client_ipaddr;
char client_hostname[33];
@@ -227,6 +266,8 @@ struct Slirp {
char *tftp_prefix;
struct tftp_session tftp_sessions[TFTP_SESSIONS_MAX];
+ ArpTable arp_table;
+
void *opaque;
};
--
1.7.4.1
^ permalink raw reply related [flat|nested] 8+ messages in thread
* Re: [Qemu-devel] [PATCH V4 1/2] [SLIRP] Simple ARP table
2011-08-02 13:19 ` [Qemu-devel] [PATCH V4 " Fabien Chouteau
@ 2011-08-03 9:13 ` Jan Kiszka
2011-08-03 10:44 ` Fabien Chouteau
2011-08-03 10:52 ` [Qemu-devel] [PATCH V5 " Fabien Chouteau
0 siblings, 2 replies; 8+ messages in thread
From: Jan Kiszka @ 2011-08-03 9:13 UTC (permalink / raw)
To: Fabien Chouteau; +Cc: qemu-devel
On 2011-08-02 15:19, Fabien Chouteau wrote:
> This patch adds a simple ARP table in Slirp and also adds handling of
> gratuitous ARP requests.
>
> Signed-off-by: Fabien Chouteau <chouteau@adacore.com>
> ---
> Makefile.objs | 2 +-
> slirp/arp_table.c | 71 +++++++++++++++++++++++++++++++++++++++++++++++++++++
> slirp/bootp.c | 21 +++++++++------
> slirp/slirp.c | 63 ++++++++++++-----------------------------------
> slirp/slirp.h | 47 ++++++++++++++++++++++++++++++++--
> 5 files changed, 145 insertions(+), 59 deletions(-)
> create mode 100644 slirp/arp_table.c
>
> diff --git a/Makefile.objs b/Makefile.objs
> index 6991a9f..0c10557 100644
> --- a/Makefile.objs
> +++ b/Makefile.objs
> @@ -151,7 +151,7 @@ common-obj-y += qemu-timer.o qemu-timer-common.o
>
> slirp-obj-y = cksum.o if.o ip_icmp.o ip_input.o ip_output.o
> slirp-obj-y += slirp.o mbuf.o misc.o sbuf.o socket.o tcp_input.o tcp_output.o
> -slirp-obj-y += tcp_subr.o tcp_timer.o udp.o bootp.o tftp.o
> +slirp-obj-y += tcp_subr.o tcp_timer.o udp.o bootp.o tftp.o arp_table.o
> common-obj-$(CONFIG_SLIRP) += $(addprefix slirp/, $(slirp-obj-y))
>
> # xen backend driver support
> diff --git a/slirp/arp_table.c b/slirp/arp_table.c
> new file mode 100644
> index 0000000..c259b42
> --- /dev/null
> +++ b/slirp/arp_table.c
> @@ -0,0 +1,71 @@
> +#include "slirp.h"
> +
> +void arp_table_add(Slirp *slirp, int ip_addr, uint8_t ethaddr[ETH_ALEN])
> +{
> + const in_addr_t broadcast_addr =
> + ~slirp->vnetwork_mask.s_addr | slirp->vnetwork_addr.s_addr;
> + ArpTable *arptbl = &slirp->arp_table;
> + int i;
> +
> + DEBUG_CALL("arp_table_add");
> + DEBUG_ARG("ip = 0x%x", ip_addr);
> + DEBUG_ARGS((dfd, " hw addr = %02x:%02x:%02x:%02x:%02x:%02x\n",
> + ethaddr[0], ethaddr[1], ethaddr[2],
> + ethaddr[3], ethaddr[4], ethaddr[5]));
> +
> + /* Check 0.0.0.0/8 invalid source-only addresses */
> + assert((ip_addr & htonl(~(0xf << 28))) != 0);
> +
> + if (ip_addr == 0xffffffff || ip_addr == broadcast_addr) {
> + /* Do not register broadcast addresses */
> + return;
> + }
> +
> + /* Search for an entry */
> + for (i = 0; i < ARP_TABLE_SIZE; i++) {
> + if (arptbl->table[i].ar_sip == ip_addr) {
> + /* Update the entry */
> + memcpy(arptbl->table[i].ar_sha, ethaddr, ETH_ALEN);
> + return;
> + }
> + }
> +
> + /* No entry found, create a new one */
> + arptbl->table[arptbl->next_victim].ar_sip = ip_addr;
> + memcpy(arptbl->table[arptbl->next_victim].ar_sha, ethaddr, ETH_ALEN);
> + arptbl->next_victim = (arptbl->next_victim + 1) % ARP_TABLE_SIZE;
> +}
> +
> +bool arp_table_search(Slirp *slirp, int in_ip_addr,
> + uint8_t out_ethaddr[ETH_ALEN])
> +{
> + const in_addr_t broadcast_addr =
> + ~slirp->vnetwork_mask.s_addr | slirp->vnetwork_addr.s_addr;
> + ArpTable *arptbl = &slirp->arp_table;
> + int i;
> +
> + DEBUG_CALL("arp_table_search");
> + DEBUG_ARG("ip = 0x%x", in_ip_addr);
> +
> + /* Check 0.0.0.0/8 invalid source-only addresses */
> + assert((in_ip_addr & htonl(~(0xf << 28))) != 0);
> +
> + /* If broadcast address */
> + if (in_ip_addr == 0xffffffff || in_ip_addr == broadcast_addr) {
> + /* return Ethernet broadcast address */
> + memset(out_ethaddr, 0xff, ETH_ALEN);
> + return 1;
> + }
> +
> + for (i = 0; i < ARP_TABLE_SIZE; i++) {
> + if (arptbl->table[i].ar_sip == in_ip_addr) {
> + memcpy(out_ethaddr, arptbl->table[i].ar_sha, ETH_ALEN);
> + DEBUG_ARGS((dfd, " found hw addr = %02x:%02x:%02x:%02x:%02x:%02x\n",
> + out_ethaddr[0], out_ethaddr[1], out_ethaddr[2],
> + out_ethaddr[3], out_ethaddr[4], out_ethaddr[5]));
> + return 1;
> + }
> + }
> +
> + return 0;
> +}
> diff --git a/slirp/bootp.c b/slirp/bootp.c
> index 1eb2ed1..efd1fe7 100644
> --- a/slirp/bootp.c
> +++ b/slirp/bootp.c
> @@ -149,6 +149,7 @@ static void bootp_reply(Slirp *slirp, const struct bootp_t *bp)
> struct in_addr preq_addr;
> int dhcp_msg_type, val;
> uint8_t *q;
> + uint8_t client_ethaddr[ETH_ALEN];
>
> /* extract exact DHCP msg type */
> dhcp_decode(bp, &dhcp_msg_type, &preq_addr);
> @@ -164,8 +165,9 @@ static void bootp_reply(Slirp *slirp, const struct bootp_t *bp)
> if (dhcp_msg_type != DHCPDISCOVER &&
> dhcp_msg_type != DHCPREQUEST)
> return;
> - /* XXX: this is a hack to get the client mac address */
> - memcpy(slirp->client_ethaddr, bp->bp_hwaddr, 6);
> +
> + /* Get client's hardware address from bootp request */
> + memcpy(client_ethaddr, bp->bp_hwaddr, ETH_ALEN);
>
> m = m_get(slirp);
> if (!m) {
> @@ -178,25 +180,25 @@ static void bootp_reply(Slirp *slirp, const struct bootp_t *bp)
>
> if (dhcp_msg_type == DHCPDISCOVER) {
> if (preq_addr.s_addr != htonl(0L)) {
> - bc = request_addr(slirp, &preq_addr, slirp->client_ethaddr);
> + bc = request_addr(slirp, &preq_addr, client_ethaddr);
> if (bc) {
> daddr.sin_addr = preq_addr;
> }
> }
> if (!bc) {
> new_addr:
> - bc = get_new_addr(slirp, &daddr.sin_addr, slirp->client_ethaddr);
> + bc = get_new_addr(slirp, &daddr.sin_addr, client_ethaddr);
> if (!bc) {
> DPRINTF("no address left\n");
> return;
> }
> }
> - memcpy(bc->macaddr, slirp->client_ethaddr, 6);
> + memcpy(bc->macaddr, client_ethaddr, ETH_ALEN);
> } else if (preq_addr.s_addr != htonl(0L)) {
> - bc = request_addr(slirp, &preq_addr, slirp->client_ethaddr);
> + bc = request_addr(slirp, &preq_addr, client_ethaddr);
> if (bc) {
> daddr.sin_addr = preq_addr;
> - memcpy(bc->macaddr, slirp->client_ethaddr, 6);
> + memcpy(bc->macaddr, client_ethaddr, ETH_ALEN);
> } else {
> daddr.sin_addr.s_addr = 0;
> }
> @@ -209,6 +211,9 @@ static void bootp_reply(Slirp *slirp, const struct bootp_t *bp)
> }
> }
>
> + /* Update ARP table for this IP address */
> + arp_table_add(slirp, daddr.sin_addr.s_addr, client_ethaddr);
> +
> saddr.sin_addr = slirp->vhost_addr;
> saddr.sin_port = htons(BOOTP_SERVER);
>
> @@ -218,7 +223,7 @@ static void bootp_reply(Slirp *slirp, const struct bootp_t *bp)
> rbp->bp_xid = bp->bp_xid;
> rbp->bp_htype = 1;
> rbp->bp_hlen = 6;
> - memcpy(rbp->bp_hwaddr, bp->bp_hwaddr, 6);
> + memcpy(rbp->bp_hwaddr, bp->bp_hwaddr, ETH_ALEN);
>
> rbp->bp_yiaddr = daddr.sin_addr; /* Client IP address */
> rbp->bp_siaddr = saddr.sin_addr; /* Server IP address */
> diff --git a/slirp/slirp.c b/slirp/slirp.c
> index df787ea..4a9a4d5 100644
> --- a/slirp/slirp.c
> +++ b/slirp/slirp.c
> @@ -31,11 +31,11 @@
> struct in_addr loopback_addr;
>
> /* emulated hosts use the MAC addr 52:55:IP:IP:IP:IP */
> -static const uint8_t special_ethaddr[6] = {
> +static const uint8_t special_ethaddr[ETH_ALEN] = {
> 0x52, 0x55, 0x00, 0x00, 0x00, 0x00
> };
>
> -static const uint8_t zero_ethaddr[6] = { 0, 0, 0, 0, 0, 0 };
> +static const uint8_t zero_ethaddr[ETH_ALEN] = { 0, 0, 0, 0, 0, 0 };
>
> /* XXX: suppress those select globals */
> fd_set *global_readfds, *global_writefds, *global_xfds;
> @@ -599,42 +599,8 @@ void slirp_select_poll(fd_set *readfds, fd_set *writefds, fd_set *xfds,
> global_xfds = NULL;
> }
>
> -#define ETH_ALEN 6
> -#define ETH_HLEN 14
> -
> -#define ETH_P_IP 0x0800 /* Internet Protocol packet */
> -#define ETH_P_ARP 0x0806 /* Address Resolution packet */
> -
> -#define ARPOP_REQUEST 1 /* ARP request */
> -#define ARPOP_REPLY 2 /* ARP reply */
> -
> -struct ethhdr
> -{
> - unsigned char h_dest[ETH_ALEN]; /* destination eth addr */
> - unsigned char h_source[ETH_ALEN]; /* source ether addr */
> - unsigned short h_proto; /* packet type ID field */
> -};
> -
> -struct arphdr
> -{
> - unsigned short ar_hrd; /* format of hardware address */
> - unsigned short ar_pro; /* format of protocol address */
> - unsigned char ar_hln; /* length of hardware address */
> - unsigned char ar_pln; /* length of protocol address */
> - unsigned short ar_op; /* ARP opcode (command) */
> -
> - /*
> - * Ethernet looks like this : This bit is variable sized however...
> - */
> - unsigned char ar_sha[ETH_ALEN]; /* sender hardware address */
> - uint32_t ar_sip; /* sender IP address */
> - unsigned char ar_tha[ETH_ALEN]; /* target hardware address */
> - uint32_t ar_tip ; /* target IP address */
> -} __attribute__((packed));
> -
> static void arp_input(Slirp *slirp, const uint8_t *pkt, int pkt_len)
> {
> - struct ethhdr *eh = (struct ethhdr *)pkt;
> struct arphdr *ah = (struct arphdr *)(pkt + ETH_HLEN);
> uint8_t arp_reply[max(ETH_HLEN + sizeof(struct arphdr), 64)];
> struct ethhdr *reh = (struct ethhdr *)arp_reply;
> @@ -645,6 +611,12 @@ static void arp_input(Slirp *slirp, const uint8_t *pkt, int pkt_len)
> ar_op = ntohs(ah->ar_op);
> switch(ar_op) {
> case ARPOP_REQUEST:
> + if (ah->ar_tip == ah->ar_sip) {
> + /* Gratuitous ARP */
> + arp_table_add(slirp, ah->ar_sip, ah->ar_sha);
> + return;
> + }
> +
> if ((ah->ar_tip & slirp->vnetwork_mask.s_addr) ==
> slirp->vnetwork_addr.s_addr) {
> if (ah->ar_tip == slirp->vnameserver_addr.s_addr ||
> @@ -657,8 +629,8 @@ static void arp_input(Slirp *slirp, const uint8_t *pkt, int pkt_len)
> return;
> arp_ok:
> memset(arp_reply, 0, sizeof(arp_reply));
> - /* XXX: make an ARP request to have the client address */
> - memcpy(slirp->client_ethaddr, eh->h_source, ETH_ALEN);
> +
> + arp_table_add(slirp, ah->ar_sip, ah->ar_sha);
>
> /* ARP request for alias/dns mac address */
> memcpy(reh->h_dest, pkt + ETH_ALEN, ETH_ALEN);
> @@ -679,11 +651,7 @@ static void arp_input(Slirp *slirp, const uint8_t *pkt, int pkt_len)
> }
> break;
> case ARPOP_REPLY:
> - /* reply to request of client mac address ? */
> - if (!memcmp(slirp->client_ethaddr, zero_ethaddr, ETH_ALEN) &&
> - ah->ar_sip == slirp->client_ipaddr.s_addr) {
> - memcpy(slirp->client_ethaddr, ah->ar_sha, ETH_ALEN);
> - }
> + arp_table_add(slirp, ah->ar_sip, ah->ar_sha);
> break;
> default:
> break;
> @@ -729,15 +697,16 @@ void if_encap(Slirp *slirp, const uint8_t *ip_data, int ip_data_len)
> {
> uint8_t buf[1600];
> struct ethhdr *eh = (struct ethhdr *)buf;
> + uint8_t ethaddr[ETH_ALEN];
> + const struct ip *iph = (const struct ip *)ip_data;
>
> if (ip_data_len + ETH_HLEN > sizeof(buf))
> return;
> -
> - if (!memcmp(slirp->client_ethaddr, zero_ethaddr, ETH_ALEN)) {
> +
> + if (!arp_table_search(slirp, iph->ip_dst.s_addr, ethaddr)) {
> uint8_t arp_req[ETH_HLEN + sizeof(struct arphdr)];
> struct ethhdr *reh = (struct ethhdr *)arp_req;
> struct arphdr *rah = (struct arphdr *)(arp_req + ETH_HLEN);
> - const struct ip *iph = (const struct ip *)ip_data;
>
> /* If the client addr is not known, there is no point in
> sending the packet to it. Normally the sender should have
> @@ -765,7 +734,7 @@ void if_encap(Slirp *slirp, const uint8_t *ip_data, int ip_data_len)
> slirp->client_ipaddr = iph->ip_dst;
> slirp_output(slirp->opaque, arp_req, sizeof(arp_req));
> } else {
> - memcpy(eh->h_dest, slirp->client_ethaddr, ETH_ALEN);
> + memcpy(eh->h_dest, ethaddr, ETH_ALEN);
> memcpy(eh->h_source, special_ethaddr, ETH_ALEN - 4);
> /* XXX: not correct */
> memcpy(&eh->h_source[2], &slirp->vhost_addr, 4);
> diff --git a/slirp/slirp.h b/slirp/slirp.h
> index 16bb6ba..2a070e6 100644
> --- a/slirp/slirp.h
> +++ b/slirp/slirp.h
> @@ -170,6 +170,48 @@ int inet_aton(const char *cp, struct in_addr *ia);
> /* osdep.c */
> int qemu_socket(int domain, int type, int protocol);
>
> +#define ETH_ALEN 6
> +#define ETH_HLEN 14
> +
> +#define ETH_P_IP 0x0800 /* Internet Protocol packet */
> +#define ETH_P_ARP 0x0806 /* Address Resolution packet */
> +
> +#define ARPOP_REQUEST 1 /* ARP request */
> +#define ARPOP_REPLY 2 /* ARP reply */
> +
> +struct ethhdr {
> + unsigned char h_dest[ETH_ALEN]; /* destination eth addr */
> + unsigned char h_source[ETH_ALEN]; /* source ether addr */
> + unsigned short h_proto; /* packet type ID field */
> +};
> +
> +struct arphdr {
> + unsigned short ar_hrd; /* format of hardware address */
> + unsigned short ar_pro; /* format of protocol address */
> + unsigned char ar_hln; /* length of hardware address */
> + unsigned char ar_pln; /* length of protocol address */
> + unsigned short ar_op; /* ARP opcode (command) */
> +
> + /*
> + * Ethernet looks like this : This bit is variable sized however...
> + */
> + unsigned char ar_sha[ETH_ALEN]; /* sender hardware address */
> + uint32_t ar_sip; /* sender IP address */
> + unsigned char ar_tha[ETH_ALEN]; /* target hardware address */
> + uint32_t ar_tip; /* target IP address */
> +} __attribute__((packed));
> +
> +#define ARP_TABLE_SIZE 16
> +
> +typedef struct ArpTable {
> + struct arphdr table[ARP_TABLE_SIZE];
> + int next_victim;
> +} ArpTable;
> +
> +void arp_table_add(Slirp *slirp, int ip_addr, uint8_t ethaddr[ETH_ALEN]);
> +
> +bool arp_table_search(Slirp *slirp, int in_ip_addr,
> + uint8_t out_ethaddr[ETH_ALEN]);
>
> struct Slirp {
> QTAILQ_ENTRY(Slirp) entry;
> @@ -181,9 +223,6 @@ struct Slirp {
> struct in_addr vdhcp_startaddr;
> struct in_addr vnameserver_addr;
>
> - /* ARP cache for the guest IP addresses (XXX: allow many entries) */
> - uint8_t client_ethaddr[6];
> -
> struct in_addr client_ipaddr;
> char client_hostname[33];
>
> @@ -227,6 +266,8 @@ struct Slirp {
> char *tftp_prefix;
> struct tftp_session tftp_sessions[TFTP_SESSIONS_MAX];
>
> + ArpTable arp_table;
> +
> void *opaque;
> };
>
> --
> 1.7.4.1
>
Looks good now and work here as well.
One last thing (I swear): We need a proper license header for
arp_table.c. Then I'll apply this and v3 of 2/2 and send out a pull
request (Anthony asked me to look after slirp).
Thanks,
Jan
--
Siemens AG, Corporate Technology, CT T DE IT 1
Corporate Competence Center Embedded Linux
^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: [Qemu-devel] [PATCH V4 1/2] [SLIRP] Simple ARP table
2011-08-03 9:13 ` Jan Kiszka
@ 2011-08-03 10:44 ` Fabien Chouteau
2011-08-03 10:52 ` [Qemu-devel] [PATCH V5 " Fabien Chouteau
1 sibling, 0 replies; 8+ messages in thread
From: Fabien Chouteau @ 2011-08-03 10:44 UTC (permalink / raw)
To: Jan Kiszka; +Cc: qemu-devel
On 03/08/2011 11:13, Jan Kiszka wrote:
> On 2011-08-02 15:19, Fabien Chouteau wrote:
>> This patch adds a simple ARP table in Slirp and also adds handling of
>> gratuitous ARP requests.
> ...
> Looks good now and work here as well.
Great!
> One last thing (I swear): We need a proper license header for
> arp_table.c.
Sure, I'll send V5 in a few minutes.
> Then I'll apply this and v3 of 2/2 and send out a pull
> request (Anthony asked me to look after slirp).
Thanks,
--
Fabien Chouteau
^ permalink raw reply [flat|nested] 8+ messages in thread
* [Qemu-devel] [PATCH V5 1/2] [SLIRP] Simple ARP table
2011-08-03 9:13 ` Jan Kiszka
2011-08-03 10:44 ` Fabien Chouteau
@ 2011-08-03 10:52 ` Fabien Chouteau
1 sibling, 0 replies; 8+ messages in thread
From: Fabien Chouteau @ 2011-08-03 10:52 UTC (permalink / raw)
To: qemu-devel; +Cc: jan.kiszka
This patch adds a simple ARP table in Slirp and also adds handling of
gratuitous ARP requests.
Signed-off-by: Fabien Chouteau <chouteau@adacore.com>
---
Makefile.objs | 2 +-
slirp/arp_table.c | 95 +++++++++++++++++++++++++++++++++++++++++++++++++++++
slirp/bootp.c | 21 +++++++----
slirp/slirp.c | 63 +++++++++--------------------------
slirp/slirp.h | 47 ++++++++++++++++++++++++--
5 files changed, 169 insertions(+), 59 deletions(-)
create mode 100644 slirp/arp_table.c
diff --git a/Makefile.objs b/Makefile.objs
index 6991a9f..0c10557 100644
--- a/Makefile.objs
+++ b/Makefile.objs
@@ -151,7 +151,7 @@ common-obj-y += qemu-timer.o qemu-timer-common.o
slirp-obj-y = cksum.o if.o ip_icmp.o ip_input.o ip_output.o
slirp-obj-y += slirp.o mbuf.o misc.o sbuf.o socket.o tcp_input.o tcp_output.o
-slirp-obj-y += tcp_subr.o tcp_timer.o udp.o bootp.o tftp.o
+slirp-obj-y += tcp_subr.o tcp_timer.o udp.o bootp.o tftp.o arp_table.o
common-obj-$(CONFIG_SLIRP) += $(addprefix slirp/, $(slirp-obj-y))
# xen backend driver support
diff --git a/slirp/arp_table.c b/slirp/arp_table.c
new file mode 100644
index 0000000..820dee2
--- /dev/null
+++ b/slirp/arp_table.c
@@ -0,0 +1,95 @@
+/*
+ * ARP table
+ *
+ * Copyright (c) 2011 AdaCore
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+#include "slirp.h"
+
+void arp_table_add(Slirp *slirp, int ip_addr, uint8_t ethaddr[ETH_ALEN])
+{
+ const in_addr_t broadcast_addr =
+ ~slirp->vnetwork_mask.s_addr | slirp->vnetwork_addr.s_addr;
+ ArpTable *arptbl = &slirp->arp_table;
+ int i;
+
+ DEBUG_CALL("arp_table_add");
+ DEBUG_ARG("ip = 0x%x", ip_addr);
+ DEBUG_ARGS((dfd, " hw addr = %02x:%02x:%02x:%02x:%02x:%02x\n",
+ ethaddr[0], ethaddr[1], ethaddr[2],
+ ethaddr[3], ethaddr[4], ethaddr[5]));
+
+ /* Check 0.0.0.0/8 invalid source-only addresses */
+ assert((ip_addr & htonl(~(0xf << 28))) != 0);
+
+ if (ip_addr == 0xffffffff || ip_addr == broadcast_addr) {
+ /* Do not register broadcast addresses */
+ return;
+ }
+
+ /* Search for an entry */
+ for (i = 0; i < ARP_TABLE_SIZE; i++) {
+ if (arptbl->table[i].ar_sip == ip_addr) {
+ /* Update the entry */
+ memcpy(arptbl->table[i].ar_sha, ethaddr, ETH_ALEN);
+ return;
+ }
+ }
+
+ /* No entry found, create a new one */
+ arptbl->table[arptbl->next_victim].ar_sip = ip_addr;
+ memcpy(arptbl->table[arptbl->next_victim].ar_sha, ethaddr, ETH_ALEN);
+ arptbl->next_victim = (arptbl->next_victim + 1) % ARP_TABLE_SIZE;
+}
+
+bool arp_table_search(Slirp *slirp, int in_ip_addr,
+ uint8_t out_ethaddr[ETH_ALEN])
+{
+ const in_addr_t broadcast_addr =
+ ~slirp->vnetwork_mask.s_addr | slirp->vnetwork_addr.s_addr;
+ ArpTable *arptbl = &slirp->arp_table;
+ int i;
+
+ DEBUG_CALL("arp_table_search");
+ DEBUG_ARG("ip = 0x%x", in_ip_addr);
+
+ /* Check 0.0.0.0/8 invalid source-only addresses */
+ assert((in_ip_addr & htonl(~(0xf << 28))) != 0);
+
+ /* If broadcast address */
+ if (in_ip_addr == 0xffffffff || in_ip_addr == broadcast_addr) {
+ /* return Ethernet broadcast address */
+ memset(out_ethaddr, 0xff, ETH_ALEN);
+ return 1;
+ }
+
+ for (i = 0; i < ARP_TABLE_SIZE; i++) {
+ if (arptbl->table[i].ar_sip == in_ip_addr) {
+ memcpy(out_ethaddr, arptbl->table[i].ar_sha, ETH_ALEN);
+ DEBUG_ARGS((dfd, " found hw addr = %02x:%02x:%02x:%02x:%02x:%02x\n",
+ out_ethaddr[0], out_ethaddr[1], out_ethaddr[2],
+ out_ethaddr[3], out_ethaddr[4], out_ethaddr[5]));
+ return 1;
+ }
+ }
+
+ return 0;
+}
diff --git a/slirp/bootp.c b/slirp/bootp.c
index 1eb2ed1..efd1fe7 100644
--- a/slirp/bootp.c
+++ b/slirp/bootp.c
@@ -149,6 +149,7 @@ static void bootp_reply(Slirp *slirp, const struct bootp_t *bp)
struct in_addr preq_addr;
int dhcp_msg_type, val;
uint8_t *q;
+ uint8_t client_ethaddr[ETH_ALEN];
/* extract exact DHCP msg type */
dhcp_decode(bp, &dhcp_msg_type, &preq_addr);
@@ -164,8 +165,9 @@ static void bootp_reply(Slirp *slirp, const struct bootp_t *bp)
if (dhcp_msg_type != DHCPDISCOVER &&
dhcp_msg_type != DHCPREQUEST)
return;
- /* XXX: this is a hack to get the client mac address */
- memcpy(slirp->client_ethaddr, bp->bp_hwaddr, 6);
+
+ /* Get client's hardware address from bootp request */
+ memcpy(client_ethaddr, bp->bp_hwaddr, ETH_ALEN);
m = m_get(slirp);
if (!m) {
@@ -178,25 +180,25 @@ static void bootp_reply(Slirp *slirp, const struct bootp_t *bp)
if (dhcp_msg_type == DHCPDISCOVER) {
if (preq_addr.s_addr != htonl(0L)) {
- bc = request_addr(slirp, &preq_addr, slirp->client_ethaddr);
+ bc = request_addr(slirp, &preq_addr, client_ethaddr);
if (bc) {
daddr.sin_addr = preq_addr;
}
}
if (!bc) {
new_addr:
- bc = get_new_addr(slirp, &daddr.sin_addr, slirp->client_ethaddr);
+ bc = get_new_addr(slirp, &daddr.sin_addr, client_ethaddr);
if (!bc) {
DPRINTF("no address left\n");
return;
}
}
- memcpy(bc->macaddr, slirp->client_ethaddr, 6);
+ memcpy(bc->macaddr, client_ethaddr, ETH_ALEN);
} else if (preq_addr.s_addr != htonl(0L)) {
- bc = request_addr(slirp, &preq_addr, slirp->client_ethaddr);
+ bc = request_addr(slirp, &preq_addr, client_ethaddr);
if (bc) {
daddr.sin_addr = preq_addr;
- memcpy(bc->macaddr, slirp->client_ethaddr, 6);
+ memcpy(bc->macaddr, client_ethaddr, ETH_ALEN);
} else {
daddr.sin_addr.s_addr = 0;
}
@@ -209,6 +211,9 @@ static void bootp_reply(Slirp *slirp, const struct bootp_t *bp)
}
}
+ /* Update ARP table for this IP address */
+ arp_table_add(slirp, daddr.sin_addr.s_addr, client_ethaddr);
+
saddr.sin_addr = slirp->vhost_addr;
saddr.sin_port = htons(BOOTP_SERVER);
@@ -218,7 +223,7 @@ static void bootp_reply(Slirp *slirp, const struct bootp_t *bp)
rbp->bp_xid = bp->bp_xid;
rbp->bp_htype = 1;
rbp->bp_hlen = 6;
- memcpy(rbp->bp_hwaddr, bp->bp_hwaddr, 6);
+ memcpy(rbp->bp_hwaddr, bp->bp_hwaddr, ETH_ALEN);
rbp->bp_yiaddr = daddr.sin_addr; /* Client IP address */
rbp->bp_siaddr = saddr.sin_addr; /* Server IP address */
diff --git a/slirp/slirp.c b/slirp/slirp.c
index df787ea..4a9a4d5 100644
--- a/slirp/slirp.c
+++ b/slirp/slirp.c
@@ -31,11 +31,11 @@
struct in_addr loopback_addr;
/* emulated hosts use the MAC addr 52:55:IP:IP:IP:IP */
-static const uint8_t special_ethaddr[6] = {
+static const uint8_t special_ethaddr[ETH_ALEN] = {
0x52, 0x55, 0x00, 0x00, 0x00, 0x00
};
-static const uint8_t zero_ethaddr[6] = { 0, 0, 0, 0, 0, 0 };
+static const uint8_t zero_ethaddr[ETH_ALEN] = { 0, 0, 0, 0, 0, 0 };
/* XXX: suppress those select globals */
fd_set *global_readfds, *global_writefds, *global_xfds;
@@ -599,42 +599,8 @@ void slirp_select_poll(fd_set *readfds, fd_set *writefds, fd_set *xfds,
global_xfds = NULL;
}
-#define ETH_ALEN 6
-#define ETH_HLEN 14
-
-#define ETH_P_IP 0x0800 /* Internet Protocol packet */
-#define ETH_P_ARP 0x0806 /* Address Resolution packet */
-
-#define ARPOP_REQUEST 1 /* ARP request */
-#define ARPOP_REPLY 2 /* ARP reply */
-
-struct ethhdr
-{
- unsigned char h_dest[ETH_ALEN]; /* destination eth addr */
- unsigned char h_source[ETH_ALEN]; /* source ether addr */
- unsigned short h_proto; /* packet type ID field */
-};
-
-struct arphdr
-{
- unsigned short ar_hrd; /* format of hardware address */
- unsigned short ar_pro; /* format of protocol address */
- unsigned char ar_hln; /* length of hardware address */
- unsigned char ar_pln; /* length of protocol address */
- unsigned short ar_op; /* ARP opcode (command) */
-
- /*
- * Ethernet looks like this : This bit is variable sized however...
- */
- unsigned char ar_sha[ETH_ALEN]; /* sender hardware address */
- uint32_t ar_sip; /* sender IP address */
- unsigned char ar_tha[ETH_ALEN]; /* target hardware address */
- uint32_t ar_tip ; /* target IP address */
-} __attribute__((packed));
-
static void arp_input(Slirp *slirp, const uint8_t *pkt, int pkt_len)
{
- struct ethhdr *eh = (struct ethhdr *)pkt;
struct arphdr *ah = (struct arphdr *)(pkt + ETH_HLEN);
uint8_t arp_reply[max(ETH_HLEN + sizeof(struct arphdr), 64)];
struct ethhdr *reh = (struct ethhdr *)arp_reply;
@@ -645,6 +611,12 @@ static void arp_input(Slirp *slirp, const uint8_t *pkt, int pkt_len)
ar_op = ntohs(ah->ar_op);
switch(ar_op) {
case ARPOP_REQUEST:
+ if (ah->ar_tip == ah->ar_sip) {
+ /* Gratuitous ARP */
+ arp_table_add(slirp, ah->ar_sip, ah->ar_sha);
+ return;
+ }
+
if ((ah->ar_tip & slirp->vnetwork_mask.s_addr) ==
slirp->vnetwork_addr.s_addr) {
if (ah->ar_tip == slirp->vnameserver_addr.s_addr ||
@@ -657,8 +629,8 @@ static void arp_input(Slirp *slirp, const uint8_t *pkt, int pkt_len)
return;
arp_ok:
memset(arp_reply, 0, sizeof(arp_reply));
- /* XXX: make an ARP request to have the client address */
- memcpy(slirp->client_ethaddr, eh->h_source, ETH_ALEN);
+
+ arp_table_add(slirp, ah->ar_sip, ah->ar_sha);
/* ARP request for alias/dns mac address */
memcpy(reh->h_dest, pkt + ETH_ALEN, ETH_ALEN);
@@ -679,11 +651,7 @@ static void arp_input(Slirp *slirp, const uint8_t *pkt, int pkt_len)
}
break;
case ARPOP_REPLY:
- /* reply to request of client mac address ? */
- if (!memcmp(slirp->client_ethaddr, zero_ethaddr, ETH_ALEN) &&
- ah->ar_sip == slirp->client_ipaddr.s_addr) {
- memcpy(slirp->client_ethaddr, ah->ar_sha, ETH_ALEN);
- }
+ arp_table_add(slirp, ah->ar_sip, ah->ar_sha);
break;
default:
break;
@@ -729,15 +697,16 @@ void if_encap(Slirp *slirp, const uint8_t *ip_data, int ip_data_len)
{
uint8_t buf[1600];
struct ethhdr *eh = (struct ethhdr *)buf;
+ uint8_t ethaddr[ETH_ALEN];
+ const struct ip *iph = (const struct ip *)ip_data;
if (ip_data_len + ETH_HLEN > sizeof(buf))
return;
-
- if (!memcmp(slirp->client_ethaddr, zero_ethaddr, ETH_ALEN)) {
+
+ if (!arp_table_search(slirp, iph->ip_dst.s_addr, ethaddr)) {
uint8_t arp_req[ETH_HLEN + sizeof(struct arphdr)];
struct ethhdr *reh = (struct ethhdr *)arp_req;
struct arphdr *rah = (struct arphdr *)(arp_req + ETH_HLEN);
- const struct ip *iph = (const struct ip *)ip_data;
/* If the client addr is not known, there is no point in
sending the packet to it. Normally the sender should have
@@ -765,7 +734,7 @@ void if_encap(Slirp *slirp, const uint8_t *ip_data, int ip_data_len)
slirp->client_ipaddr = iph->ip_dst;
slirp_output(slirp->opaque, arp_req, sizeof(arp_req));
} else {
- memcpy(eh->h_dest, slirp->client_ethaddr, ETH_ALEN);
+ memcpy(eh->h_dest, ethaddr, ETH_ALEN);
memcpy(eh->h_source, special_ethaddr, ETH_ALEN - 4);
/* XXX: not correct */
memcpy(&eh->h_source[2], &slirp->vhost_addr, 4);
diff --git a/slirp/slirp.h b/slirp/slirp.h
index 16bb6ba..2a070e6 100644
--- a/slirp/slirp.h
+++ b/slirp/slirp.h
@@ -170,6 +170,48 @@ int inet_aton(const char *cp, struct in_addr *ia);
/* osdep.c */
int qemu_socket(int domain, int type, int protocol);
+#define ETH_ALEN 6
+#define ETH_HLEN 14
+
+#define ETH_P_IP 0x0800 /* Internet Protocol packet */
+#define ETH_P_ARP 0x0806 /* Address Resolution packet */
+
+#define ARPOP_REQUEST 1 /* ARP request */
+#define ARPOP_REPLY 2 /* ARP reply */
+
+struct ethhdr {
+ unsigned char h_dest[ETH_ALEN]; /* destination eth addr */
+ unsigned char h_source[ETH_ALEN]; /* source ether addr */
+ unsigned short h_proto; /* packet type ID field */
+};
+
+struct arphdr {
+ unsigned short ar_hrd; /* format of hardware address */
+ unsigned short ar_pro; /* format of protocol address */
+ unsigned char ar_hln; /* length of hardware address */
+ unsigned char ar_pln; /* length of protocol address */
+ unsigned short ar_op; /* ARP opcode (command) */
+
+ /*
+ * Ethernet looks like this : This bit is variable sized however...
+ */
+ unsigned char ar_sha[ETH_ALEN]; /* sender hardware address */
+ uint32_t ar_sip; /* sender IP address */
+ unsigned char ar_tha[ETH_ALEN]; /* target hardware address */
+ uint32_t ar_tip; /* target IP address */
+} __attribute__((packed));
+
+#define ARP_TABLE_SIZE 16
+
+typedef struct ArpTable {
+ struct arphdr table[ARP_TABLE_SIZE];
+ int next_victim;
+} ArpTable;
+
+void arp_table_add(Slirp *slirp, int ip_addr, uint8_t ethaddr[ETH_ALEN]);
+
+bool arp_table_search(Slirp *slirp, int in_ip_addr,
+ uint8_t out_ethaddr[ETH_ALEN]);
struct Slirp {
QTAILQ_ENTRY(Slirp) entry;
@@ -181,9 +223,6 @@ struct Slirp {
struct in_addr vdhcp_startaddr;
struct in_addr vnameserver_addr;
- /* ARP cache for the guest IP addresses (XXX: allow many entries) */
- uint8_t client_ethaddr[6];
-
struct in_addr client_ipaddr;
char client_hostname[33];
@@ -227,6 +266,8 @@ struct Slirp {
char *tftp_prefix;
struct tftp_session tftp_sessions[TFTP_SESSIONS_MAX];
+ ArpTable arp_table;
+
void *opaque;
};
--
1.7.4.1
^ permalink raw reply related [flat|nested] 8+ messages in thread
end of thread, other threads:[~2011-08-03 10:53 UTC | newest]
Thread overview: 8+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2011-08-01 16:18 [Qemu-devel] [PATCH V3 1/2] [SLIRP] Simple ARP table Fabien Chouteau
2011-08-01 16:18 ` [Qemu-devel] [PATCH V3 2/2] [SLIRP] Delayed IP packets Fabien Chouteau
2011-08-01 20:16 ` [Qemu-devel] [PATCH V3 1/2] [SLIRP] Simple ARP table Jan Kiszka
2011-08-02 9:58 ` Fabien Chouteau
2011-08-02 13:19 ` [Qemu-devel] [PATCH V4 " Fabien Chouteau
2011-08-03 9:13 ` Jan Kiszka
2011-08-03 10:44 ` Fabien Chouteau
2011-08-03 10:52 ` [Qemu-devel] [PATCH V5 " Fabien Chouteau
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