[iproute PATCH v2 0/3] ss: Allow excluding a socket table from being queried

[iproute PATCH v2 0/3] ss: Allow excluding a socket table from being queried

[Phil Sutter]

The first patch in this series adds the new functionality, the remaining
two refactor the code a bit.

Note that Patch 1 creates warnings with checkpatch due to overlong
lines, but patch 2 removes them again so for the sake of readability I
left this as is.

Changes since v1:
- Fixed checkpatch errors in patch 2/3.

Phil Sutter (3):
  ss: Allow excluding a socket table from being queried
  ss: Put filter DB parsing into a separate function
  ss: Drop filter_default_dbs()

 man/man8/ss.8 |   8 +++-
 misc/ss.c     | 147 +++++++++++++++++++++++++++-------------------------------
 2 files changed, 76 insertions(+), 79 deletions(-)

-- 
2.16.1

[iproute PATCH v2 1/3] ss: Allow excluding a socket table from being queried

[Phil Sutter]

The original problem was that a simple call to 'ss' leads to loading of
sctp_diag kernel module which might not be desired. While searching for
a workaround, it became clear how inconvenient it is to exclude a single
socket table from being queried.

This patch allows to prefix an item passed to '-A' parameter with an
exclamation mark to inverse its meaning.

Signed-off-by: Phil Sutter <phil@nwl.cc>
---
 man/man8/ss.8 |   8 ++++-
 misc/ss.c     | 108 ++++++++++++++++++++++++++++++++--------------------------
 2 files changed, 66 insertions(+), 50 deletions(-)

diff --git a/man/man8/ss.8 b/man/man8/ss.8
index 973afbe0b386b..28033d8f01dda 100644
--- a/man/man8/ss.8
+++ b/man/man8/ss.8
@@ -317,7 +317,10 @@ Currently the following families are supported: unix, inet, inet6, link, netlink
 List of socket tables to dump, separated by commas. The following identifiers
 are understood: all, inet, tcp, udp, raw, unix, packet, netlink, unix_dgram,
 unix_stream, unix_seqpacket, packet_raw, packet_dgram, dccp, sctp,
-vsock_stream, vsock_dgram.
+vsock_stream, vsock_dgram. Any item in the list may optionally be prefixed by
+an exclamation mark
+.RB ( ! )
+to exclude that socket table from being dumped.
 .TP
 .B \-D FILE, \-\-diag=FILE
 Do not display anything, just dump raw information about TCP sockets to FILE after applying filters. If FILE is - stdout is used.
@@ -380,6 +383,9 @@ Find all local processes connected to X server.
 .TP
 .B ss -o state fin-wait-1 '( sport = :http or sport = :https )' dst 193.233.7/24
 List all the tcp sockets in state FIN-WAIT-1 for our apache to network 193.233.7/24 and look at their timers.
+.TP
+.B ss -a -A 'all,!tcp'
+List sockets in all states from all socket tables but TCP.
 .SH SEE ALSO
 .BR ip (8),
 .br
diff --git a/misc/ss.c b/misc/ss.c
index 6338820bf4a01..05522176f1e61 100644
--- a/misc/ss.c
+++ b/misc/ss.c
@@ -329,10 +329,14 @@ static const struct filter default_afs[AF_MAX] = {
 static int do_default = 1;
 static struct filter current_filter;
 
-static void filter_db_set(struct filter *f, int db)
+static void filter_db_set(struct filter *f, int db, bool enable)
 {
-	f->states   |= default_dbs[db].states;
-	f->dbs	    |= 1 << db;
+	if (enable) {
+		f->states   |= default_dbs[db].states;
+		f->dbs	    |= 1 << db;
+	} else {
+		f->dbs &= ~(1 << db);
+	}
 	do_default   = 0;
 }
 
@@ -349,21 +353,21 @@ static int filter_af_get(struct filter *f, int af)
 	return !!(f->families & FAMILY_MASK(af));
 }
 
-static void filter_default_dbs(struct filter *f)
+static void filter_default_dbs(struct filter *f, bool enable)
 {
-	filter_db_set(f, UDP_DB);
-	filter_db_set(f, DCCP_DB);
-	filter_db_set(f, TCP_DB);
-	filter_db_set(f, RAW_DB);
-	filter_db_set(f, UNIX_ST_DB);
-	filter_db_set(f, UNIX_DG_DB);
-	filter_db_set(f, UNIX_SQ_DB);
-	filter_db_set(f, PACKET_R_DB);
-	filter_db_set(f, PACKET_DG_DB);
-	filter_db_set(f, NETLINK_DB);
-	filter_db_set(f, SCTP_DB);
-	filter_db_set(f, VSOCK_ST_DB);
-	filter_db_set(f, VSOCK_DG_DB);
+	filter_db_set(f, UDP_DB, enable);
+	filter_db_set(f, DCCP_DB, enable);
+	filter_db_set(f, TCP_DB, enable);
+	filter_db_set(f, RAW_DB, enable);
+	filter_db_set(f, UNIX_ST_DB, enable);
+	filter_db_set(f, UNIX_DG_DB, enable);
+	filter_db_set(f, UNIX_SQ_DB, enable);
+	filter_db_set(f, PACKET_R_DB, enable);
+	filter_db_set(f, PACKET_DG_DB, enable);
+	filter_db_set(f, NETLINK_DB, enable);
+	filter_db_set(f, SCTP_DB, enable);
+	filter_db_set(f, VSOCK_ST_DB, enable);
+	filter_db_set(f, VSOCK_DG_DB, enable);
 }
 
 static void filter_states_set(struct filter *f, int states)
@@ -4712,19 +4716,19 @@ int main(int argc, char *argv[])
 			follow_events = 1;
 			break;
 		case 'd':
-			filter_db_set(&current_filter, DCCP_DB);
+			filter_db_set(&current_filter, DCCP_DB, true);
 			break;
 		case 't':
-			filter_db_set(&current_filter, TCP_DB);
+			filter_db_set(&current_filter, TCP_DB, true);
 			break;
 		case 'S':
-			filter_db_set(&current_filter, SCTP_DB);
+			filter_db_set(&current_filter, SCTP_DB, true);
 			break;
 		case 'u':
-			filter_db_set(&current_filter, UDP_DB);
+			filter_db_set(&current_filter, UDP_DB, true);
 			break;
 		case 'w':
-			filter_db_set(&current_filter, RAW_DB);
+			filter_db_set(&current_filter, RAW_DB, true);
 			break;
 		case 'x':
 			filter_af_set(&current_filter, AF_UNIX);
@@ -4781,59 +4785,65 @@ int main(int argc, char *argv[])
 			}
 			p = p1 = optarg;
 			do {
+				bool enable = true;
+
 				if ((p1 = strchr(p, ',')) != NULL)
 					*p1 = 0;
+				if (p[0] == '!') {
+					enable = false;
+					p++;
+				}
 				if (strcmp(p, "all") == 0) {
-					filter_default_dbs(&current_filter);
+					filter_default_dbs(&current_filter, enable);
 				} else if (strcmp(p, "inet") == 0) {
-					filter_db_set(&current_filter, UDP_DB);
-					filter_db_set(&current_filter, DCCP_DB);
-					filter_db_set(&current_filter, TCP_DB);
-					filter_db_set(&current_filter, SCTP_DB);
-					filter_db_set(&current_filter, RAW_DB);
+					filter_db_set(&current_filter, UDP_DB, enable);
+					filter_db_set(&current_filter, DCCP_DB, enable);
+					filter_db_set(&current_filter, TCP_DB, enable);
+					filter_db_set(&current_filter, SCTP_DB, enable);
+					filter_db_set(&current_filter, RAW_DB, enable);
 				} else if (strcmp(p, "udp") == 0) {
-					filter_db_set(&current_filter, UDP_DB);
+					filter_db_set(&current_filter, UDP_DB, enable);
 				} else if (strcmp(p, "dccp") == 0) {
-					filter_db_set(&current_filter, DCCP_DB);
+					filter_db_set(&current_filter, DCCP_DB, enable);
 				} else if (strcmp(p, "tcp") == 0) {
-					filter_db_set(&current_filter, TCP_DB);
+					filter_db_set(&current_filter, TCP_DB, enable);
 				} else if (strcmp(p, "sctp") == 0) {
-					filter_db_set(&current_filter, SCTP_DB);
+					filter_db_set(&current_filter, SCTP_DB, enable);
 				} else if (strcmp(p, "raw") == 0) {
-					filter_db_set(&current_filter, RAW_DB);
+					filter_db_set(&current_filter, RAW_DB, enable);
 				} else if (strcmp(p, "unix") == 0) {
-					filter_db_set(&current_filter, UNIX_ST_DB);
-					filter_db_set(&current_filter, UNIX_DG_DB);
-					filter_db_set(&current_filter, UNIX_SQ_DB);
+					filter_db_set(&current_filter, UNIX_ST_DB, enable);
+					filter_db_set(&current_filter, UNIX_DG_DB, enable);
+					filter_db_set(&current_filter, UNIX_SQ_DB, enable);
 				} else if (strcasecmp(p, "unix_stream") == 0 ||
 					   strcmp(p, "u_str") == 0) {
-					filter_db_set(&current_filter, UNIX_ST_DB);
+					filter_db_set(&current_filter, UNIX_ST_DB, enable);
 				} else if (strcasecmp(p, "unix_dgram") == 0 ||
 					   strcmp(p, "u_dgr") == 0) {
-					filter_db_set(&current_filter, UNIX_DG_DB);
+					filter_db_set(&current_filter, UNIX_DG_DB, enable);
 				} else if (strcasecmp(p, "unix_seqpacket") == 0 ||
 					   strcmp(p, "u_seq") == 0) {
-					filter_db_set(&current_filter, UNIX_SQ_DB);
+					filter_db_set(&current_filter, UNIX_SQ_DB, enable);
 				} else if (strcmp(p, "packet") == 0) {
-					filter_db_set(&current_filter, PACKET_R_DB);
-					filter_db_set(&current_filter, PACKET_DG_DB);
+					filter_db_set(&current_filter, PACKET_R_DB, enable);
+					filter_db_set(&current_filter, PACKET_DG_DB, enable);
 				} else if (strcmp(p, "packet_raw") == 0 ||
 					   strcmp(p, "p_raw") == 0) {
-					filter_db_set(&current_filter, PACKET_R_DB);
+					filter_db_set(&current_filter, PACKET_R_DB, enable);
 				} else if (strcmp(p, "packet_dgram") == 0 ||
 					   strcmp(p, "p_dgr") == 0) {
-					filter_db_set(&current_filter, PACKET_DG_DB);
+					filter_db_set(&current_filter, PACKET_DG_DB, enable);
 				} else if (strcmp(p, "netlink") == 0) {
-					filter_db_set(&current_filter, NETLINK_DB);
+					filter_db_set(&current_filter, NETLINK_DB, enable);
 				} else if (strcmp(p, "vsock") == 0) {
-					filter_db_set(&current_filter, VSOCK_ST_DB);
-					filter_db_set(&current_filter, VSOCK_DG_DB);
+					filter_db_set(&current_filter, VSOCK_ST_DB, enable);
+					filter_db_set(&current_filter, VSOCK_DG_DB, enable);
 				} else if (strcmp(p, "vsock_stream") == 0 ||
 					   strcmp(p, "v_str") == 0) {
-					filter_db_set(&current_filter, VSOCK_ST_DB);
+					filter_db_set(&current_filter, VSOCK_ST_DB, enable);
 				} else if (strcmp(p, "vsock_dgram") == 0 ||
 					   strcmp(p, "v_dgr") == 0) {
-					filter_db_set(&current_filter, VSOCK_DG_DB);
+					filter_db_set(&current_filter, VSOCK_DG_DB, enable);
 				} else {
 					fprintf(stderr, "ss: \"%s\" is illegal socket table id\n", p);
 					usage();
@@ -4926,7 +4936,7 @@ int main(int argc, char *argv[])
 
 	if (do_default) {
 		state_filter = state_filter ? state_filter : SS_CONN;
-		filter_default_dbs(&current_filter);
+		filter_default_dbs(&current_filter, true);
 	}
 
 	filter_states_set(&current_filter, state_filter);
-- 
2.16.1

[iproute PATCH v2 2/3] ss: Put filter DB parsing into a separate function

[Phil Sutter]

Use a table for database name parsing. The tricky bit is to allow for
association of a (nearly) arbitrary number of DBs with each name.
Luckily the number is not fully arbitrary as there is an upper bound of
MAX_DB items. Since it is not possible to have a variable length
array inside a variable length array, use this knowledge to make the
inner array of fixed length. But since DB values start from zero, an
explicit end entry needs to be present as well, so the inner array has
to be MAX_DB + 1 in size.

Signed-off-by: Phil Sutter <phil@nwl.cc>
---
Changes since v1:
- Fix checkpatch errors.

 misc/ss.c | 114 ++++++++++++++++++++++++++++++--------------------------------
 1 file changed, 56 insertions(+), 58 deletions(-)

diff --git a/misc/ss.c b/misc/ss.c
index 05522176f1e61..83e476a0407e5 100644
--- a/misc/ss.c
+++ b/misc/ss.c
@@ -340,6 +340,61 @@ static void filter_db_set(struct filter *f, int db, bool enable)
 	do_default   = 0;
 }
 
+static int filter_db_parse(struct filter *f, const char *s)
+{
+	const struct {
+		const char *name;
+		int dbs[MAX_DB + 1];
+	} db_name_tbl[] = {
+#define ENTRY(name, ...) { #name, { __VA_ARGS__, MAX_DB } }
+		ENTRY(all, UDP_DB, DCCP_DB, TCP_DB, RAW_DB,
+			   UNIX_ST_DB, UNIX_DG_DB, UNIX_SQ_DB,
+			   PACKET_R_DB, PACKET_DG_DB, NETLINK_DB,
+			   SCTP_DB, VSOCK_ST_DB, VSOCK_DG_DB),
+		ENTRY(inet, UDP_DB, DCCP_DB, TCP_DB, SCTP_DB, RAW_DB),
+		ENTRY(udp, UDP_DB),
+		ENTRY(dccp, DCCP_DB),
+		ENTRY(tcp, TCP_DB),
+		ENTRY(sctp, SCTP_DB),
+		ENTRY(raw, RAW_DB),
+		ENTRY(unix, UNIX_ST_DB, UNIX_DG_DB, UNIX_SQ_DB),
+		ENTRY(unix_stream, UNIX_ST_DB),
+		ENTRY(u_str, UNIX_ST_DB),	/* alias for unix_stream */
+		ENTRY(unix_dgram, UNIX_DG_DB),
+		ENTRY(u_dgr, UNIX_DG_DB),	/* alias for unix_dgram */
+		ENTRY(unix_seqpacket, UNIX_SQ_DB),
+		ENTRY(u_seq, UNIX_SQ_DB),	/* alias for unix_seqpacket */
+		ENTRY(packet, PACKET_R_DB, PACKET_DG_DB),
+		ENTRY(packet_raw, PACKET_R_DB),
+		ENTRY(p_raw, PACKET_R_DB),	/* alias for packet_raw */
+		ENTRY(packet_dgram, PACKET_DG_DB),
+		ENTRY(p_dgr, PACKET_DG_DB),	/* alias for packet_dgram */
+		ENTRY(netlink, NETLINK_DB),
+		ENTRY(vsock, VSOCK_ST_DB, VSOCK_DG_DB),
+		ENTRY(vsock_stream, VSOCK_ST_DB),
+		ENTRY(v_str, VSOCK_ST_DB),	/* alias for vsock_stream */
+		ENTRY(vsock_dgram, VSOCK_DG_DB),
+		ENTRY(v_dgr, VSOCK_DG_DB),	/* alias for vsock_dgram */
+#undef ENTRY
+	};
+	bool enable = true;
+	unsigned int i;
+	const int *dbp;
+
+	if (s[0] == '!') {
+		enable = false;
+		s++;
+	}
+	for (i = 0; i < ARRAY_SIZE(db_name_tbl); i++) {
+		if (strcmp(s, db_name_tbl[i].name))
+			continue;
+		for (dbp = db_name_tbl[i].dbs; *dbp != MAX_DB; dbp++)
+			filter_db_set(f, *dbp, enable);
+		return 0;
+	}
+	return -1;
+}
+
 static void filter_af_set(struct filter *f, int af)
 {
 	f->states	   |= default_afs[af].states;
@@ -4785,66 +4840,9 @@ int main(int argc, char *argv[])
 			}
 			p = p1 = optarg;
 			do {
-				bool enable = true;
-
 				if ((p1 = strchr(p, ',')) != NULL)
 					*p1 = 0;
-				if (p[0] == '!') {
-					enable = false;
-					p++;
-				}
-				if (strcmp(p, "all") == 0) {
-					filter_default_dbs(&current_filter, enable);
-				} else if (strcmp(p, "inet") == 0) {
-					filter_db_set(&current_filter, UDP_DB, enable);
-					filter_db_set(&current_filter, DCCP_DB, enable);
-					filter_db_set(&current_filter, TCP_DB, enable);
-					filter_db_set(&current_filter, SCTP_DB, enable);
-					filter_db_set(&current_filter, RAW_DB, enable);
-				} else if (strcmp(p, "udp") == 0) {
-					filter_db_set(&current_filter, UDP_DB, enable);
-				} else if (strcmp(p, "dccp") == 0) {
-					filter_db_set(&current_filter, DCCP_DB, enable);
-				} else if (strcmp(p, "tcp") == 0) {
-					filter_db_set(&current_filter, TCP_DB, enable);
-				} else if (strcmp(p, "sctp") == 0) {
-					filter_db_set(&current_filter, SCTP_DB, enable);
-				} else if (strcmp(p, "raw") == 0) {
-					filter_db_set(&current_filter, RAW_DB, enable);
-				} else if (strcmp(p, "unix") == 0) {
-					filter_db_set(&current_filter, UNIX_ST_DB, enable);
-					filter_db_set(&current_filter, UNIX_DG_DB, enable);
-					filter_db_set(&current_filter, UNIX_SQ_DB, enable);
-				} else if (strcasecmp(p, "unix_stream") == 0 ||
-					   strcmp(p, "u_str") == 0) {
-					filter_db_set(&current_filter, UNIX_ST_DB, enable);
-				} else if (strcasecmp(p, "unix_dgram") == 0 ||
-					   strcmp(p, "u_dgr") == 0) {
-					filter_db_set(&current_filter, UNIX_DG_DB, enable);
-				} else if (strcasecmp(p, "unix_seqpacket") == 0 ||
-					   strcmp(p, "u_seq") == 0) {
-					filter_db_set(&current_filter, UNIX_SQ_DB, enable);
-				} else if (strcmp(p, "packet") == 0) {
-					filter_db_set(&current_filter, PACKET_R_DB, enable);
-					filter_db_set(&current_filter, PACKET_DG_DB, enable);
-				} else if (strcmp(p, "packet_raw") == 0 ||
-					   strcmp(p, "p_raw") == 0) {
-					filter_db_set(&current_filter, PACKET_R_DB, enable);
-				} else if (strcmp(p, "packet_dgram") == 0 ||
-					   strcmp(p, "p_dgr") == 0) {
-					filter_db_set(&current_filter, PACKET_DG_DB, enable);
-				} else if (strcmp(p, "netlink") == 0) {
-					filter_db_set(&current_filter, NETLINK_DB, enable);
-				} else if (strcmp(p, "vsock") == 0) {
-					filter_db_set(&current_filter, VSOCK_ST_DB, enable);
-					filter_db_set(&current_filter, VSOCK_DG_DB, enable);
-				} else if (strcmp(p, "vsock_stream") == 0 ||
-					   strcmp(p, "v_str") == 0) {
-					filter_db_set(&current_filter, VSOCK_ST_DB, enable);
-				} else if (strcmp(p, "vsock_dgram") == 0 ||
-					   strcmp(p, "v_dgr") == 0) {
-					filter_db_set(&current_filter, VSOCK_DG_DB, enable);
-				} else {
+				if (filter_db_parse(&current_filter, p)) {
 					fprintf(stderr, "ss: \"%s\" is illegal socket table id\n", p);
 					usage();
 				}
-- 
2.16.1

[iproute PATCH v2 3/3] ss: Drop filter_default_dbs()

[Phil Sutter]

Instead call filter_db_parse(..., "all"). This eliminates the duplicate
default DB definition.

Signed-off-by: Phil Sutter <phil@nwl.cc>
---
 misc/ss.c | 19 +------------------
 1 file changed, 1 insertion(+), 18 deletions(-)

diff --git a/misc/ss.c b/misc/ss.c
index 83e476a0407e5..fc8e2a0d719fd 100644
--- a/misc/ss.c
+++ b/misc/ss.c
@@ -408,23 +408,6 @@ static int filter_af_get(struct filter *f, int af)
 	return !!(f->families & FAMILY_MASK(af));
 }
 
-static void filter_default_dbs(struct filter *f, bool enable)
-{
-	filter_db_set(f, UDP_DB, enable);
-	filter_db_set(f, DCCP_DB, enable);
-	filter_db_set(f, TCP_DB, enable);
-	filter_db_set(f, RAW_DB, enable);
-	filter_db_set(f, UNIX_ST_DB, enable);
-	filter_db_set(f, UNIX_DG_DB, enable);
-	filter_db_set(f, UNIX_SQ_DB, enable);
-	filter_db_set(f, PACKET_R_DB, enable);
-	filter_db_set(f, PACKET_DG_DB, enable);
-	filter_db_set(f, NETLINK_DB, enable);
-	filter_db_set(f, SCTP_DB, enable);
-	filter_db_set(f, VSOCK_ST_DB, enable);
-	filter_db_set(f, VSOCK_DG_DB, enable);
-}
-
 static void filter_states_set(struct filter *f, int states)
 {
 	if (states)
@@ -4934,7 +4917,7 @@ int main(int argc, char *argv[])
 
 	if (do_default) {
 		state_filter = state_filter ? state_filter : SS_CONN;
-		filter_default_dbs(&current_filter, true);
+		filter_db_parse(&current_filter, "all");
 	}
 
 	filter_states_set(&current_filter, state_filter);
-- 
2.16.1