[iproute2] tipc: call a sub-routine in separate socket

[iproute2] tipc: call a sub-routine in separate socket

[Hoang Le]

When receiving a result from first query to netlink, we may exec
a another query inside the callback. If calling this sub-routine
in the same socket, it will be discarded the result from previous
exection.
To avoid this we perform a nested query in separate socket.

Fixes: 202102830663 ("tipc: use the libmnl functions in lib/mnl_utils.c")
Signed-off-by: Hoang Le <hoang.h.le@dektech.com.au>
Acked-by: Jon Maloy <jmaloy@redhat.com>
---
 tipc/bearer.c | 50 +++++++++++++++++++++++++++++++++++++++++++++-----
 tipc/link.c   | 15 +++++++++++++--
 tipc/socket.c | 17 +++++++++++++++--
 3 files changed, 73 insertions(+), 9 deletions(-)

diff --git a/tipc/bearer.c b/tipc/bearer.c
index 2afc48b9b108..968293bc9160 100644
--- a/tipc/bearer.c
+++ b/tipc/bearer.c
@@ -20,7 +20,9 @@
 #include <linux/tipc.h>
 #include <linux/genetlink.h>
 #include <linux/if.h>
+#include <libmnl/libmnl.h>
 
+#include "mnl_utils.h"
 #include "utils.h"
 #include "cmdl.h"
 #include "msg.h"
@@ -98,16 +100,28 @@ static int get_netid_cb(const struct nlmsghdr *nlh, void *data)
 
 static int generate_multicast(short af, char *buf, int bufsize)
 {
+	struct mnlu_gen_socket bearer_nlg;
 	struct nlmsghdr *nlh;
 	int netid;
+	int err = 0;
 
-	nlh = msg_init(TIPC_NL_NET_GET);
+	err = mnlu_gen_socket_open(&bearer_nlg, TIPC_GENL_V2_NAME,
+				   TIPC_GENL_V2_VERSION);
+	if (err)
+		return -1;
+
+	nlh = mnlu_gen_socket_cmd_prepare(&bearer_nlg, TIPC_NL_NET_GET,
+					  NLM_F_REQUEST | NLM_F_DUMP);
 	if (!nlh) {
 		fprintf(stderr, "error, message initialization failed\n");
+		mnlu_gen_socket_close(&bearer_nlg);
 		return -1;
 	}
-	if (msg_dumpit(nlh, get_netid_cb, &netid)) {
+
+	err = mnlu_gen_socket_sndrcv(&bearer_nlg, nlh, get_netid_cb, &netid);
+	if (err) {
 		fprintf(stderr, "error, failed to fetch TIPC network id from kernel\n");
+		mnlu_gen_socket_close(&bearer_nlg);
 		return -EINVAL;
 	}
 	if (af == AF_INET)
@@ -115,6 +129,7 @@ static int generate_multicast(short af, char *buf, int bufsize)
 	else
 		snprintf(buf, bufsize, "ff02::%u", netid);
 
+	mnlu_gen_socket_close(&bearer_nlg);
 	return 0;
 }
 
@@ -794,10 +809,35 @@ static int bearer_get_udp_cb(const struct nlmsghdr *nlh, void *data)
 	if ((cb_data->attr == TIPC_NLA_UDP_REMOTE) &&
 	    (cb_data->prop == UDP_PROP_IP) &&
 	    opts[TIPC_NLA_UDP_MULTI_REMOTEIP]) {
-		struct genlmsghdr *genl = mnl_nlmsg_get_payload(cb_data->nlh);
+		struct mnlu_gen_socket bearer_nlg;
+		struct nlattr *attr;
+		struct nlmsghdr *h;
+		const char *bname;
+		int err = 0;
+
+		err = mnlu_gen_socket_open(&bearer_nlg, TIPC_GENL_V2_NAME,
+					   TIPC_GENL_V2_VERSION);
+		if (err)
+			return -1;
+
+		h = mnlu_gen_socket_cmd_prepare(&bearer_nlg,
+						TIPC_NL_UDP_GET_REMOTEIP,
+						NLM_F_REQUEST | NLM_F_DUMP);
+		if (!h) {
+			fprintf(stderr, "error, message initialization failed\n");
+			mnlu_gen_socket_close(&bearer_nlg);
+			return -1;
+		}
 
-		genl->cmd = TIPC_NL_UDP_GET_REMOTEIP;
-		return msg_dumpit(cb_data->nlh, bearer_dump_udp_cb, NULL);
+		attr = mnl_attr_nest_start(h, TIPC_NLA_BEARER);
+		bname = mnl_attr_get_str(attrs[TIPC_NLA_BEARER_NAME]);
+		mnl_attr_put_strz(h, TIPC_NLA_BEARER_NAME, bname);
+		mnl_attr_nest_end(h, attr);
+
+		err = mnlu_gen_socket_sndrcv(&bearer_nlg, h,
+					     bearer_dump_udp_cb, NULL);
+		mnlu_gen_socket_close(&bearer_nlg);
+		return err;
 	}
 
 	addr = mnl_attr_get_payload(opts[cb_data->attr]);
diff --git a/tipc/link.c b/tipc/link.c
index 2123f109c694..9994ada2a367 100644
--- a/tipc/link.c
+++ b/tipc/link.c
@@ -17,7 +17,9 @@
 #include <linux/tipc_netlink.h>
 #include <linux/tipc.h>
 #include <linux/genetlink.h>
+#include <libmnl/libmnl.h>
 
+#include "mnl_utils.h"
 #include "cmdl.h"
 #include "msg.h"
 #include "link.h"
@@ -993,13 +995,20 @@ exit:
 
 static int link_mon_peer_list(uint32_t mon_ref)
 {
+	struct mnlu_gen_socket link_nlg;
 	struct nlmsghdr *nlh;
 	struct nlattr *nest;
 	int err = 0;
 
-	nlh = msg_init(TIPC_NL_MON_PEER_GET);
+	err = mnlu_gen_socket_open(&link_nlg, TIPC_GENL_V2_NAME,
+				   TIPC_GENL_V2_VERSION);
+	if (err)
+		return -1;
+	nlh = mnlu_gen_socket_cmd_prepare(&link_nlg, TIPC_NL_MON_PEER_GET,
+					  NLM_F_REQUEST | NLM_F_DUMP);
 	if (!nlh) {
 		fprintf(stderr, "error, message initialisation failed\n");
+		mnlu_gen_socket_close(&link_nlg);
 		return -1;
 	}
 
@@ -1007,7 +1016,9 @@ static int link_mon_peer_list(uint32_t mon_ref)
 	mnl_attr_put_u32(nlh, TIPC_NLA_MON_REF, mon_ref);
 	mnl_attr_nest_end(nlh, nest);
 
-	err = msg_dumpit(nlh, link_mon_peer_list_cb, NULL);
+	err = mnlu_gen_socket_sndrcv(&link_nlg, nlh, link_mon_peer_list_cb,
+				     NULL);
+	mnlu_gen_socket_close(&link_nlg);
 	return err;
 }
 
diff --git a/tipc/socket.c b/tipc/socket.c
index deae12af4409..597ffd91af52 100644
--- a/tipc/socket.c
+++ b/tipc/socket.c
@@ -15,7 +15,9 @@
 #include <linux/tipc.h>
 #include <linux/tipc_netlink.h>
 #include <linux/genetlink.h>
+#include <libmnl/libmnl.h>
 
+#include "mnl_utils.h"
 #include "cmdl.h"
 #include "msg.h"
 #include "socket.h"
@@ -44,12 +46,21 @@ static int publ_list_cb(const struct nlmsghdr *nlh, void *data)
 
 static int publ_list(uint32_t sock)
 {
+	struct mnlu_gen_socket sock_nlg;
 	struct nlmsghdr *nlh;
 	struct nlattr *nest;
+	int err;
 
-	nlh = msg_init(TIPC_NL_PUBL_GET);
+	err = mnlu_gen_socket_open(&sock_nlg, TIPC_GENL_V2_NAME,
+				   TIPC_GENL_V2_VERSION);
+	if (err)
+		return -1;
+
+	nlh = mnlu_gen_socket_cmd_prepare(&sock_nlg, TIPC_NL_PUBL_GET,
+					  NLM_F_REQUEST | NLM_F_DUMP);
 	if (!nlh) {
 		fprintf(stderr, "error, message initialisation failed\n");
+		mnlu_gen_socket_close(&sock_nlg);
 		return -1;
 	}
 
@@ -57,7 +68,9 @@ static int publ_list(uint32_t sock)
 	mnl_attr_put_u32(nlh, TIPC_NLA_SOCK_REF, sock);
 	mnl_attr_nest_end(nlh, nest);
 
-	return msg_dumpit(nlh, publ_list_cb, NULL);
+	err = mnlu_gen_socket_sndrcv(&sock_nlg, nlh, publ_list_cb, NULL);
+	mnlu_gen_socket_close(&sock_nlg);
+	return err;
 }
 
 static int sock_list_cb(const struct nlmsghdr *nlh, void *data)
-- 
2.25.1

Re: [iproute2] tipc: call a sub-routine in separate socket

[David Ahern]

On 5/5/21 9:27 PM, Hoang Le wrote:
> When receiving a result from first query to netlink, we may exec
> a another query inside the callback. If calling this sub-routine
> in the same socket, it will be discarded the result from previous
> exection.
> To avoid this we perform a nested query in separate socket.
> 
> Fixes: 202102830663 ("tipc: use the libmnl functions in lib/mnl_utils.c")
> Signed-off-by: Hoang Le <hoang.h.le@dektech.com.au>
> Acked-by: Jon Maloy <jmaloy@redhat.com>
> ---
>  tipc/bearer.c | 50 +++++++++++++++++++++++++++++++++++++++++++++-----
>  tipc/link.c   | 15 +++++++++++++--
>  tipc/socket.c | 17 +++++++++++++++--
>  3 files changed, 73 insertions(+), 9 deletions(-)
> 

applied, thanks