* [PATCH iproute2-next v2 2/3] ss: add support for cgroup v2 information and filtering
2020-05-09 16:52 [PATCH iproute2-next v2 1/3] ss: introduce cgroup2 cache and helper functions Dmitry Yakunin
@ 2020-05-09 16:52 ` Dmitry Yakunin
2020-05-09 16:52 ` [PATCH iproute2-next v2 3/3] ss: add checks for bc filter support Dmitry Yakunin
2020-05-13 2:03 ` [PATCH iproute2-next v2 1/3] ss: introduce cgroup2 cache and helper functions David Ahern
2 siblings, 0 replies; 6+ messages in thread
From: Dmitry Yakunin @ 2020-05-09 16:52 UTC (permalink / raw)
To: netdev, dsahern; +Cc: cgroups
This patch introduces two new features: obtaining cgroup information and
filtering sockets by cgroups. These features work based on cgroup v2 ID
field in the socket (kernel should be compiled with CONFIG_SOCK_CGROUP_DATA).
Cgroup information can be obtained by specifying --cgroup flag and now contains
only pathname. For faster pathname lookups cgroup cache is implemented. This
cache is filled on ss startup and missed entries are resolved and saved
on the fly.
Cgroup filter extends EXPRESSION and allows to specify cgroup pathname
(relative or absolute) to obtain sockets attached only to this cgroup.
Filter syntax: ss [ cgroup PATHNAME ]
Examples:
ss -a cgroup /sys/fs/cgroup/unified (or ss -a cgroup .)
ss -a cgroup /sys/fs/cgroup/unified/cgroup1 (or ss -a cgroup cgroup1)
v2:
- style fixes (David Ahern)
Signed-off-by: Dmitry Yakunin <zeil@yandex-team.ru>
---
include/uapi/linux/inet_diag.h | 2 ++
man/man8/ss.8 | 9 +++++++
misc/ss.c | 61 ++++++++++++++++++++++++++++++++++++++++++
misc/ssfilter.h | 2 ++
misc/ssfilter.y | 22 ++++++++++++++-
5 files changed, 95 insertions(+), 1 deletion(-)
diff --git a/include/uapi/linux/inet_diag.h b/include/uapi/linux/inet_diag.h
index 0c1c781..f009abf 100644
--- a/include/uapi/linux/inet_diag.h
+++ b/include/uapi/linux/inet_diag.h
@@ -96,6 +96,7 @@ enum {
INET_DIAG_BC_MARK_COND,
INET_DIAG_BC_S_EQ,
INET_DIAG_BC_D_EQ,
+ INET_DIAG_BC_CGROUP_COND, /* u64 cgroup v2 ID */
};
struct inet_diag_hostcond {
@@ -157,6 +158,7 @@ enum {
INET_DIAG_MD5SIG,
INET_DIAG_ULP_INFO,
INET_DIAG_SK_BPF_STORAGES,
+ INET_DIAG_CGROUP_ID,
__INET_DIAG_MAX,
};
diff --git a/man/man8/ss.8 b/man/man8/ss.8
index 023d771..894cb20 100644
--- a/man/man8/ss.8
+++ b/man/man8/ss.8
@@ -281,6 +281,15 @@ Class id set by net_cls cgroup. If class is zero this shows priority
set by SO_PRIORITY.
.RE
.TP
+.B \-\-cgroup
+Show cgroup information. Below fields may appear:
+.RS
+.P
+.TP
+.B cgroup
+Cgroup v2 pathname. This pathname is relative to the mount point of the hierarchy.
+.RE
+.TP
.B \-K, \-\-kill
Attempts to forcibly close sockets. This option displays sockets that are
successfully closed and silently skips sockets that the kernel does not support
diff --git a/misc/ss.c b/misc/ss.c
index 75fde23..b9e6b15 100644
--- a/misc/ss.c
+++ b/misc/ss.c
@@ -36,6 +36,7 @@
#include "namespace.h"
#include "SNAPSHOT.h"
#include "rt_names.h"
+#include "cg_map.h"
#include <linux/tcp.h>
#include <linux/sock_diag.h>
@@ -122,6 +123,7 @@ static int follow_events;
static int sctp_ino;
static int show_tipcinfo;
static int show_tos;
+static int show_cgroup;
int oneline;
enum col_id {
@@ -797,6 +799,7 @@ struct sockstat {
char *name;
char *peer_name;
__u32 mark;
+ __u64 cgroup_id;
};
struct dctcpstat {
@@ -1417,6 +1420,9 @@ static void sock_details_print(struct sockstat *s)
if (s->mark)
out(" fwmark:0x%x", s->mark);
+
+ if (s->cgroup_id)
+ out(" cgroup:%s", cg_id_to_path(s->cgroup_id));
}
static void sock_addr_print(const char *addr, char *delim, const char *port,
@@ -1643,6 +1649,7 @@ struct aafilter {
unsigned int iface;
__u32 mark;
__u32 mask;
+ __u64 cgroup_id;
struct aafilter *next;
};
@@ -1771,6 +1778,12 @@ static int run_ssfilter(struct ssfilter *f, struct sockstat *s)
return (s->mark & a->mask) == a->mark;
}
+ case SSF_CGROUPCOND:
+ {
+ struct aafilter *a = (void *)f->pred;
+
+ return s->cgroup_id == a->cgroup_id;
+ }
/* Yup. It is recursion. Sorry. */
case SSF_AND:
return run_ssfilter(f->pred, s) && run_ssfilter(f->post, s);
@@ -1963,6 +1976,23 @@ static int ssfilter_bytecompile(struct ssfilter *f, char **bytecode)
return inslen;
}
+ case SSF_CGROUPCOND:
+ {
+ struct aafilter *a = (void *)f->pred;
+ struct instr {
+ struct inet_diag_bc_op op;
+ __u64 cgroup_id;
+ } __attribute__((packed));
+ int inslen = sizeof(struct instr);
+
+ if (!(*bytecode = malloc(inslen))) abort();
+ ((struct instr *)*bytecode)[0] = (struct instr) {
+ { INET_DIAG_BC_CGROUP_COND, inslen, inslen + 4 },
+ a->cgroup_id,
+ };
+
+ return inslen;
+ }
default:
abort();
}
@@ -2300,6 +2330,22 @@ void *parse_markmask(const char *markmask)
return res;
}
+void *parse_cgroupcond(const char *path)
+{
+ struct aafilter *res;
+ __u64 id;
+
+ id = get_cgroup2_id(path);
+ if (!id)
+ return NULL;
+
+ res = malloc(sizeof(*res));
+ if (res)
+ res->cgroup_id = id;
+
+ return res;
+}
+
static void proc_ctx_print(struct sockstat *s)
{
char *buf;
@@ -3104,6 +3150,9 @@ static void parse_diag_msg(struct nlmsghdr *nlh, struct sockstat *s)
s->mark = 0;
if (tb[INET_DIAG_MARK])
s->mark = rta_getattr_u32(tb[INET_DIAG_MARK]);
+ s->cgroup_id = 0;
+ if (tb[INET_DIAG_CGROUP_ID])
+ s->cgroup_id = rta_getattr_u64(tb[INET_DIAG_CGROUP_ID]);
if (tb[INET_DIAG_PROTOCOL])
s->raw_prot = rta_getattr_u8(tb[INET_DIAG_PROTOCOL]);
else
@@ -3171,6 +3220,11 @@ static int inet_show_sock(struct nlmsghdr *nlh,
out(" class_id:%#x", rta_getattr_u32(tb[INET_DIAG_CLASS_ID]));
}
+ if (show_cgroup) {
+ if (tb[INET_DIAG_CGROUP_ID])
+ out(" cgroup:%s", cg_id_to_path(rta_getattr_u64(tb[INET_DIAG_CGROUP_ID])));
+ }
+
if (show_mem || (show_tcpinfo && s->type != IPPROTO_UDP)) {
if (!oneline)
out("\n\t");
@@ -4996,6 +5050,7 @@ static void _usage(FILE *dest)
" --tipcinfo show internal tipc socket information\n"
" -s, --summary show socket usage summary\n"
" --tos show tos and priority information\n"
+" --cgroup show cgroup information\n"
" -b, --bpf show bpf filter socket information\n"
" -E, --events continually display sockets as they are destroyed\n"
" -Z, --context display process SELinux security contexts\n"
@@ -5106,6 +5161,8 @@ static int scan_state(const char *state)
/* Values of 'x' are already used so a non-character is used */
#define OPT_XDPSOCK 260
+#define OPT_CGROUP 261
+
static const struct option long_opts[] = {
{ "numeric", 0, 0, 'n' },
{ "resolve", 0, 0, 'r' },
@@ -5142,6 +5199,7 @@ static const struct option long_opts[] = {
{ "net", 1, 0, 'N' },
{ "tipcinfo", 0, 0, OPT_TIPCINFO},
{ "tos", 0, 0, OPT_TOS },
+ { "cgroup", 0, 0, OPT_CGROUP },
{ "kill", 0, 0, 'K' },
{ "no-header", 0, 0, 'H' },
{ "xdp", 0, 0, OPT_XDPSOCK},
@@ -5329,6 +5387,9 @@ int main(int argc, char *argv[])
case OPT_TOS:
show_tos = 1;
break;
+ case OPT_CGROUP:
+ show_cgroup = 1;
+ break;
case 'K':
current_filter.kill = 1;
break;
diff --git a/misc/ssfilter.h b/misc/ssfilter.h
index f5b0bc8..d85c084 100644
--- a/misc/ssfilter.h
+++ b/misc/ssfilter.h
@@ -11,6 +11,7 @@
#define SSF_S_AUTO 9
#define SSF_DEVCOND 10
#define SSF_MARKMASK 11
+#define SSF_CGROUPCOND 12
#include <stdbool.h>
@@ -25,3 +26,4 @@ int ssfilter_parse(struct ssfilter **f, int argc, char **argv, FILE *fp);
void *parse_hostcond(char *addr, bool is_port);
void *parse_devcond(char *name);
void *parse_markmask(const char *markmask);
+void *parse_cgroupcond(const char *path);
diff --git a/misc/ssfilter.y b/misc/ssfilter.y
index a901ae7..b417579 100644
--- a/misc/ssfilter.y
+++ b/misc/ssfilter.y
@@ -36,7 +36,7 @@ static void yyerror(char *s)
%}
-%token HOSTCOND DCOND SCOND DPORT SPORT LEQ GEQ NEQ AUTOBOUND DEVCOND DEVNAME MARKMASK FWMARK
+%token HOSTCOND DCOND SCOND DPORT SPORT LEQ GEQ NEQ AUTOBOUND DEVCOND DEVNAME MARKMASK FWMARK CGROUPCOND CGROUPPATH
%left '|'
%left '&'
%nonassoc '!'
@@ -156,6 +156,14 @@ expr: '(' exprlist ')'
{
$$ = alloc_node(SSF_NOT, alloc_node(SSF_MARKMASK, $3));
}
+ | CGROUPPATH eq CGROUPCOND
+ {
+ $$ = alloc_node(SSF_CGROUPCOND, $3);
+ }
+ | CGROUPPATH NEQ CGROUPCOND
+ {
+ $$ = alloc_node(SSF_NOT, alloc_node(SSF_CGROUPCOND, $3));
+ }
| AUTOBOUND
{
$$ = alloc_node(SSF_S_AUTO, NULL);
@@ -276,6 +284,10 @@ int yylex(void)
tok_type = FWMARK;
return FWMARK;
}
+ if (strcmp(curtok, "cgroup") == 0) {
+ tok_type = CGROUPPATH;
+ return CGROUPPATH;
+ }
if (strcmp(curtok, ">=") == 0 ||
strcmp(curtok, "ge") == 0 ||
strcmp(curtok, "geq") == 0)
@@ -318,6 +330,14 @@ int yylex(void)
}
return MARKMASK;
}
+ if (tok_type == CGROUPPATH) {
+ yylval = (void*)parse_cgroupcond(curtok);
+ if (yylval == NULL) {
+ fprintf(stderr, "Cannot parse cgroup %s.\n", curtok);
+ exit(1);
+ }
+ return CGROUPCOND;
+ }
yylval = (void*)parse_hostcond(curtok, tok_type == SPORT || tok_type == DPORT);
if (yylval == NULL) {
fprintf(stderr, "Cannot parse dst/src address.\n");
--
2.7.4
^ permalink raw reply related [flat|nested] 6+ messages in thread
* [PATCH iproute2-next v2 3/3] ss: add checks for bc filter support
2020-05-09 16:52 [PATCH iproute2-next v2 1/3] ss: introduce cgroup2 cache and helper functions Dmitry Yakunin
2020-05-09 16:52 ` [PATCH iproute2-next v2 2/3] ss: add support for cgroup v2 information and filtering Dmitry Yakunin
@ 2020-05-09 16:52 ` Dmitry Yakunin
2020-05-13 2:03 ` [PATCH iproute2-next v2 1/3] ss: introduce cgroup2 cache and helper functions David Ahern
2 siblings, 0 replies; 6+ messages in thread
From: Dmitry Yakunin @ 2020-05-09 16:52 UTC (permalink / raw)
To: netdev, dsahern; +Cc: cgroups
As noted by David Ahern, now if some bytecode filter is not supported
by running kernel printed error message is not clear. This patch is attempt to
detect such case and print correct message. This is done by providing checking
function for new filter types. As example check function for cgroup filter
is implemented. It sends correct lightweight request (idiag_states = 0)
with zero cgroup condition to the kernel and checks returned errno. If filter
is not supported EINVAL is returned. Result of checking is cached to
avoid extra checks if several same filters are specified.
Signed-off-by: Dmitry Yakunin <zeil@yandex-team.ru>
---
misc/Makefile | 2 +-
misc/ss.c | 17 +--------
misc/ss_util.h | 22 +++++++++++
misc/ssfilter.h | 34 +++++++++--------
misc/ssfilter.y | 9 ++++-
misc/ssfilter_check.c | 103 ++++++++++++++++++++++++++++++++++++++++++++++++++
6 files changed, 154 insertions(+), 33 deletions(-)
create mode 100644 misc/ss_util.h
create mode 100644 misc/ssfilter_check.c
diff --git a/misc/Makefile b/misc/Makefile
index 1debfb1..50dae79 100644
--- a/misc/Makefile
+++ b/misc/Makefile
@@ -1,5 +1,5 @@
# SPDX-License-Identifier: GPL-2.0
-SSOBJ=ss.o ssfilter.tab.o
+SSOBJ=ss.o ssfilter_check.o ssfilter.tab.o
LNSTATOBJ=lnstat.o lnstat_util.o
TARGETS=ss nstat ifstat rtacct lnstat
diff --git a/misc/ss.c b/misc/ss.c
index b9e6b15..1891e9c 100644
--- a/misc/ss.c
+++ b/misc/ss.c
@@ -29,6 +29,7 @@
#include <limits.h>
#include <stdarg.h>
+#include "ss_util.h"
#include "utils.h"
#include "rt_names.h"
#include "ll_map.h"
@@ -39,8 +40,6 @@
#include "cg_map.h"
#include <linux/tcp.h>
-#include <linux/sock_diag.h>
-#include <linux/inet_diag.h>
#include <linux/unix_diag.h>
#include <linux/netdevice.h> /* for MAX_ADDR_LEN */
#include <linux/filter.h>
@@ -63,24 +62,10 @@
#define AF_VSOCK PF_VSOCK
#endif
-#define MAGIC_SEQ 123456
#define BUF_CHUNK (1024 * 1024) /* Buffer chunk allocation size */
#define BUF_CHUNKS_MAX 5 /* Maximum number of allocated buffer chunks */
#define LEN_ALIGN(x) (((x) + 1) & ~1)
-#define DIAG_REQUEST(_req, _r) \
- struct { \
- struct nlmsghdr nlh; \
- _r; \
- } _req = { \
- .nlh = { \
- .nlmsg_type = SOCK_DIAG_BY_FAMILY, \
- .nlmsg_flags = NLM_F_ROOT|NLM_F_MATCH|NLM_F_REQUEST,\
- .nlmsg_seq = MAGIC_SEQ, \
- .nlmsg_len = sizeof(_req), \
- }, \
- }
-
#if HAVE_SELINUX
#include <selinux/selinux.h>
#else
diff --git a/misc/ss_util.h b/misc/ss_util.h
new file mode 100644
index 0000000..f7e40bb
--- /dev/null
+++ b/misc/ss_util.h
@@ -0,0 +1,22 @@
+#ifndef __SS_UTIL_H__
+#define __SS_UTIL_H__
+
+#include <linux/sock_diag.h>
+#include <linux/inet_diag.h>
+
+#define MAGIC_SEQ 123456
+
+#define DIAG_REQUEST(_req, _r) \
+ struct { \
+ struct nlmsghdr nlh; \
+ _r; \
+ } _req = { \
+ .nlh = { \
+ .nlmsg_type = SOCK_DIAG_BY_FAMILY, \
+ .nlmsg_flags = NLM_F_ROOT|NLM_F_MATCH|NLM_F_REQUEST,\
+ .nlmsg_seq = MAGIC_SEQ, \
+ .nlmsg_len = sizeof(_req), \
+ }, \
+ }
+
+#endif /* __SS_UTIL_H__ */
diff --git a/misc/ssfilter.h b/misc/ssfilter.h
index d85c084..0be3b1e 100644
--- a/misc/ssfilter.h
+++ b/misc/ssfilter.h
@@ -1,20 +1,24 @@
-/* SPDX-License-Identifier: GPL-2.0 */
-#define SSF_DCOND 0
-#define SSF_SCOND 1
-#define SSF_OR 2
-#define SSF_AND 3
-#define SSF_NOT 4
-#define SSF_D_GE 5
-#define SSF_D_LE 6
-#define SSF_S_GE 7
-#define SSF_S_LE 8
-#define SSF_S_AUTO 9
-#define SSF_DEVCOND 10
-#define SSF_MARKMASK 11
-#define SSF_CGROUPCOND 12
-
#include <stdbool.h>
+enum {
+ SSF_DCOND,
+ SSF_SCOND,
+ SSF_OR,
+ SSF_AND,
+ SSF_NOT,
+ SSF_D_GE,
+ SSF_D_LE,
+ SSF_S_GE,
+ SSF_S_LE,
+ SSF_S_AUTO,
+ SSF_DEVCOND,
+ SSF_MARKMASK,
+ SSF_CGROUPCOND,
+ SSF__MAX
+};
+
+bool ssfilter_is_supported(int type);
+
struct ssfilter
{
int type;
diff --git a/misc/ssfilter.y b/misc/ssfilter.y
index b417579..8e16b44 100644
--- a/misc/ssfilter.y
+++ b/misc/ssfilter.y
@@ -12,7 +12,14 @@ typedef struct ssfilter * ssfilter_t;
static struct ssfilter * alloc_node(int type, void *pred)
{
- struct ssfilter *n = malloc(sizeof(*n));
+ struct ssfilter *n;
+
+ if (!ssfilter_is_supported(type)) {
+ fprintf(stderr, "It looks like such filter is not supported! Too old kernel?\n");
+ exit(-1);
+ }
+
+ n = malloc(sizeof(*n));
if (n == NULL)
abort();
n->type = type;
diff --git a/misc/ssfilter_check.c b/misc/ssfilter_check.c
new file mode 100644
index 0000000..38c960c
--- /dev/null
+++ b/misc/ssfilter_check.c
@@ -0,0 +1,103 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <errno.h>
+
+#include "libnetlink.h"
+#include "ssfilter.h"
+#include "ss_util.h"
+
+static int dummy_filter(struct nlmsghdr *n, void *arg)
+{
+ /* just stops rtnl_dump_filter() */
+ return -1;
+}
+
+static bool cgroup_filter_check(void)
+{
+ struct sockaddr_nl nladdr = { .nl_family = AF_NETLINK };
+ DIAG_REQUEST(req, struct inet_diag_req_v2 r);
+ struct instr {
+ struct inet_diag_bc_op op;
+ __u64 cgroup_id;
+ } __attribute__((packed));
+ int inslen = sizeof(struct instr);
+ struct instr instr = {
+ { INET_DIAG_BC_CGROUP_COND, inslen, inslen + 4 },
+ 0
+ };
+ struct rtnl_handle rth;
+ struct iovec iov[3];
+ struct msghdr msg;
+ struct rtattr rta;
+ int ret = false;
+ int iovlen = 3;
+
+ if (rtnl_open_byproto(&rth, 0, NETLINK_SOCK_DIAG))
+ return false;
+ rth.dump = MAGIC_SEQ;
+ rth.flags = RTNL_HANDLE_F_SUPPRESS_NLERR;
+
+ memset(&req.r, 0, sizeof(req.r));
+ req.r.sdiag_family = AF_INET;
+ req.r.sdiag_protocol = IPPROTO_TCP;
+ req.nlh.nlmsg_len += RTA_LENGTH(inslen);
+
+ rta.rta_type = INET_DIAG_REQ_BYTECODE;
+ rta.rta_len = RTA_LENGTH(inslen);
+
+ iov[0] = (struct iovec) { &req, sizeof(req) };
+ iov[1] = (struct iovec) { &rta, sizeof(rta) };
+ iov[2] = (struct iovec) { &instr, inslen };
+
+ msg = (struct msghdr) {
+ .msg_name = (void *)&nladdr,
+ .msg_namelen = sizeof(nladdr),
+ .msg_iov = iov,
+ .msg_iovlen = iovlen,
+ };
+
+ if (sendmsg(rth.fd, &msg, 0) < 0)
+ goto out;
+
+ if (rtnl_dump_filter(&rth, dummy_filter, NULL) < 0) {
+ ret = (errno != EINVAL);
+ goto out;
+ }
+
+ ret = true;
+
+out:
+ rtnl_close(&rth);
+
+ return ret;
+}
+
+
+struct filter_check_t {
+ bool (*check)(void);
+ int checked:1,
+ supported:1;
+};
+
+static struct filter_check_t filter_checks[SSF__MAX] = {
+ [SSF_CGROUPCOND] = { cgroup_filter_check, 0 },
+};
+
+bool ssfilter_is_supported(int type)
+{
+ struct filter_check_t f;
+
+ if (type >= SSF__MAX)
+ return false;
+
+ f = filter_checks[type];
+ if (!f.check)
+ return true;
+
+ if (!f.checked) {
+ f.supported = f.check();
+ f.checked = 1;
+ }
+
+ return f.supported;
+}
--
2.7.4
^ permalink raw reply related [flat|nested] 6+ messages in thread