[PATCH iproute2] ss: remove non-functional slabinfo

[PATCH iproute2] ss: remove non-functional slabinfo

[Stephen Hemminger]

Ss was using slabinfo to try and intuit TCP statistics.
The slabinfo changed several times since 2.4 and all these statistics
are broken by renames and slab merging. Plus slabinfo does not exist
at all if kernel is compiled with SLUB option.

This has been broken for many years and is not worth fixing;
rather than trying to fix kernel, just trim away the no longer
valid statistics.

Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>
---
 misc/ss.c | 103 ++++--------------------------------------------------
 1 file changed, 6 insertions(+), 97 deletions(-)

diff --git a/misc/ss.c b/misc/ss.c
index 3ed7e66962f3..41e7762bb61f 100644
--- a/misc/ss.c
+++ b/misc/ss.c
@@ -474,7 +474,6 @@ static FILE *generic_proc_open(const char *env, const char *name)
 							"net/packet")
 #define net_netlink_open()	generic_proc_open("PROC_NET_NETLINK", \
 							"net/netlink")
-#define slabinfo_open()		generic_proc_open("PROC_SLABINFO", "slabinfo")
 #define net_sockstat_open()	generic_proc_open("PROC_NET_SOCKSTAT", \
 							"net/sockstat")
 #define net_sockstat6_open()	generic_proc_open("PROC_NET_SOCKSTAT6", \
@@ -728,67 +727,6 @@ next:
 	return cnt;
 }
 
-/* Get stats from slab */
-
-struct slabstat {
-	int socks;
-	int tcp_ports;
-	int tcp_tws;
-	int tcp_syns;
-	int skbs;
-};
-
-static struct slabstat slabstat;
-
-static int get_slabstat(struct slabstat *s)
-{
-	char buf[256];
-	FILE *fp;
-	int cnt;
-	static int slabstat_valid;
-	static const char * const slabstat_ids[] = {
-		"sock",
-		"tcp_bind_bucket",
-		"tcp_tw_bucket",
-		"tcp_open_request",
-		"skbuff_head_cache",
-	};
-
-	if (slabstat_valid)
-		return 0;
-
-	memset(s, 0, sizeof(*s));
-
-	fp = slabinfo_open();
-	if (!fp)
-		return -1;
-
-	cnt = sizeof(*s)/sizeof(int);
-
-	if (!fgets(buf, sizeof(buf), fp)) {
-		fclose(fp);
-		return -1;
-	}
-	while (fgets(buf, sizeof(buf), fp) != NULL) {
-		int i;
-
-		for (i = 0; i < ARRAY_SIZE(slabstat_ids); i++) {
-			if (memcmp(buf, slabstat_ids[i], strlen(slabstat_ids[i])) == 0) {
-				sscanf(buf, "%*s%d", ((int *)s) + i);
-				cnt--;
-				break;
-			}
-		}
-		if (cnt <= 0)
-			break;
-	}
-
-	slabstat_valid = 1;
-
-	fclose(fp);
-	return 0;
-}
-
 static unsigned long long cookie_sk_get(const uint32_t *cookie)
 {
 	return (((unsigned long long)cookie[1] << 31) << 1) | cookie[0];
@@ -3372,7 +3310,7 @@ static int tcp_show(struct filter *f)
 {
 	FILE *fp = NULL;
 	char *buf = NULL;
-	int bufsize = 64*1024;
+	int bufsize = 1024*1024;
 
 	if (!filter_af_get(f, AF_INET) && !filter_af_get(f, AF_INET6))
 		return 0;
@@ -3387,27 +3325,6 @@ static int tcp_show(struct filter *f)
 		return 0;
 
 	/* Sigh... We have to parse /proc/net/tcp... */
-
-
-	/* Estimate amount of sockets and try to allocate
-	 * huge buffer to read all the table at one read.
-	 * Limit it by 16MB though. The assumption is: as soon as
-	 * kernel was able to hold information about N connections,
-	 * it is able to give us some memory for snapshot.
-	 */
-	if (1) {
-		get_slabstat(&slabstat);
-
-		int guess = slabstat.socks+slabstat.tcp_syns;
-
-		if (f->states&(1<<SS_TIME_WAIT))
-			guess += slabstat.tcp_tws;
-		if (guess > (16*1024*1024)/128)
-			guess = (16*1024*1024)/128;
-		guess *= 128;
-		if (guess > bufsize)
-			bufsize = guess;
-	}
 	while (bufsize >= 64*1024) {
 		if ((buf = malloc(bufsize)) != NULL)
 			break;
@@ -4666,23 +4583,15 @@ static int print_summary(void)
 	if (get_snmp_int("Tcp:", "CurrEstab", &tcp_estab) < 0)
 		perror("ss: get_snmpstat");
 
-	get_slabstat(&slabstat);
-
-	printf("Total: %d (kernel %d)\n", s.socks, slabstat.socks);
+	printf("Total: %d\n", s.socks);
 
-	printf("TCP:   %d (estab %d, closed %d, orphaned %d, synrecv %d, timewait %d/%d), ports %d\n",
-	       s.tcp_total + slabstat.tcp_syns + s.tcp_tws,
-	       tcp_estab,
-	       s.tcp_total - (s.tcp4_hashed+s.tcp6_hashed-s.tcp_tws),
-	       s.tcp_orphans,
-	       slabstat.tcp_syns,
-	       s.tcp_tws, slabstat.tcp_tws,
-	       slabstat.tcp_ports
-	       );
+	printf("TCP:   %d (estab %d, closed %d, orphaned %d, timewait %d)\n",
+	       s.tcp_total + s.tcp_tws, tcp_estab,
+	       s.tcp_total - (s.tcp4_hashed + s.tcp6_hashed - s.tcp_tws),
+	       s.tcp_orphans, s.tcp_tws);
 
 	printf("\n");
 	printf("Transport Total     IP        IPv6\n");
-	printf("*	  %-9d %-9s %-9s\n", slabstat.socks, "-", "-");
 	printf("RAW	  %-9d %-9d %-9d\n", s.raw4+s.raw6, s.raw4, s.raw6);
 	printf("UDP	  %-9d %-9d %-9d\n", s.udp4+s.udp6, s.udp4, s.udp6);
 	printf("TCP	  %-9d %-9d %-9d\n", s.tcp4_hashed+s.tcp6_hashed, s.tcp4_hashed, s.tcp6_hashed);
-- 
2.17.0