--- /dev/null
+/*
+ * tcp_metrics.c "ip tcp_metrics/tcpmetrics"
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * version 2 as published by the Free Software Foundation;
+ *
+ * Authors: Julian Anastasov <ja@ssi.bg>, August 2012
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <errno.h>
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <arpa/inet.h>
+#include <sys/ioctl.h>
+#include <linux/if.h>
+
+#include <linux/genetlink.h>
+#include <linux/tcp_metrics.h>
+
+#include "utils.h"
+#include "ip_common.h"
+#include "libgenl.h"
+
+static void usage(void)
+{
+ fprintf(stderr, "Usage: ip tcp_metrics/tcpmetrics { COMMAND | help }\n");
+ fprintf(stderr, " ip tcp_metrics { show | flush } SELECTOR\n");
+ fprintf(stderr, " ip tcp_metrics delete [ address ] ADDRESS\n");
+ fprintf(stderr, "SELECTOR := [ [ address ] PREFIX ]\n");
+ exit(-1);
+}
+
+/* netlink socket */
+static struct rtnl_handle grth = { .fd = -1 };
+static int genl_family = -1;
+
+#define TCPM_REQUEST(_req, _bufsiz, _cmd, _flags) \
+ GENL_REQUEST(_req, _bufsiz, genl_family, 0, \
+ TCP_METRICS_GENL_VERSION, _cmd, _flags)
+
+#define CMD_LIST 0x0001 /* list, lst, show */
+#define CMD_DEL 0x0002 /* delete, remove */
+#define CMD_FLUSH 0x0004 /* flush */
+
+static struct {
+ char *name;
+ int code;
+} cmds[] = {
+ { "list", CMD_LIST },
+ { "lst", CMD_LIST },
+ { "show", CMD_LIST },
+ { "delete", CMD_DEL },
+ { "remove", CMD_DEL },
+ { "flush", CMD_FLUSH },
+};
+
+static char *metric_name[TCP_METRIC_MAX + 1] = {
+ [TCP_METRIC_RTT] = "rtt",
+ [TCP_METRIC_RTTVAR] = "rttvar",
+ [TCP_METRIC_SSTHRESH] = "ssthresh",
+ [TCP_METRIC_CWND] = "cwnd",
+ [TCP_METRIC_REORDERING] = "reordering",
+};
+
+static struct
+{
+ int flushed;
+ char *flushb;
+ int flushp;
+ int flushe;
+ int cmd;
+ inet_prefix addr;
+} f;
+
+static int flush_update(void)
+{
+ if (rtnl_send_check(&grth, f.flushb, f.flushp) < 0) {
+ perror("Failed to send flush request\n");
+ return -1;
+ }
+ f.flushp = 0;
+ return 0;
+}
+
+static int process_msg(const struct sockaddr_nl *who, struct nlmsghdr *n,
+ void *arg)
+{
+ FILE *fp = (FILE *) arg;
+ struct genlmsghdr *ghdr;
+ struct rtattr *attrs[TCP_METRICS_ATTR_MAX + 1], *a;
+ int len = n->nlmsg_len;
+ char abuf[256];
+ inet_prefix addr;
+ int family, i, atype;
+
+ if (n->nlmsg_type != genl_family)
+ return -1;
+
+ len -= NLMSG_LENGTH(GENL_HDRLEN);
+ if (len < 0)
+ return -1;
+
+ ghdr = NLMSG_DATA(n);
+ if (ghdr->cmd != TCP_METRICS_CMD_GET)
+ return 0;
+
+ parse_rtattr(attrs, TCP_METRICS_ATTR_MAX, (void *) ghdr + GENL_HDRLEN,
+ len);
+
+ a = attrs[TCP_METRICS_ATTR_ADDR_IPV4];
+ if (a) {
+ if (f.addr.family && f.addr.family != AF_INET)
+ return 0;
+ memcpy(&addr.data, RTA_DATA(a), 4);
+ addr.bytelen = 4;
+ family = AF_INET;
+ atype = TCP_METRICS_ATTR_ADDR_IPV4;
+ } else {
+ a = attrs[TCP_METRICS_ATTR_ADDR_IPV6];
+ if (a) {
+ if (f.addr.family && f.addr.family != AF_INET6)
+ return 0;
+ memcpy(&addr.data, RTA_DATA(a), 16);
+ addr.bytelen = 16;
+ family = AF_INET6;
+ atype = TCP_METRICS_ATTR_ADDR_IPV6;
+ } else
+ return 0;
+ }
+
+ if (f.addr.family && f.addr.bitlen >= 0 &&
+ inet_addr_match(&addr, &f.addr, f.addr.bitlen))
+ return 0;
+
+ if (f.flushb) {
+ struct nlmsghdr *fn;
+ TCPM_REQUEST(req2, 128, TCP_METRICS_CMD_DEL, NLM_F_REQUEST);
+
+ addattr_l(&req2.n, sizeof(req2), atype, &addr.data,
+ addr.bytelen);
+
+ if (NLMSG_ALIGN(f.flushp) + req2.n.nlmsg_len > f.flushe) {
+ if (flush_update())
+ return -1;
+ }
+ fn = (struct nlmsghdr *) (f.flushb + NLMSG_ALIGN(f.flushp));
+ memcpy(fn, &req2.n, req2.n.nlmsg_len);
+ fn->nlmsg_seq = ++grth.seq;
+ f.flushp = (((char *) fn) + req2.n.nlmsg_len) - f.flushb;
+ f.flushed++;
+ if (show_stats < 2)
+ return 0;
+ }
+
+ if (f.cmd & (CMD_DEL | CMD_FLUSH))
+ fprintf(fp, "Deleted ");
+
+ fprintf(fp, "%s",
+ format_host(family, RTA_PAYLOAD(a), &addr.data,
+ abuf, sizeof(abuf)));
+
+ a = attrs[TCP_METRICS_ATTR_AGE];
+ if (a) {
+ __u64 val = rta_getattr_u64(a);
+
+ fprintf(fp, " age %llu.%03llusec",
+ val / 1000, val % 1000);
+ }
+
+ a = attrs[TCP_METRICS_ATTR_TW_TS_STAMP];
+ if (a) {
+ __s32 val = (__s32) rta_getattr_u32(a);
+ __u32 tsval;
+
+ a = attrs[TCP_METRICS_ATTR_TW_TSVAL];
+ tsval = a ? rta_getattr_u32(a) : 0;
+ fprintf(fp, " tw_ts %u/%dsec ago", tsval, val);
+ }
+
+ a = attrs[TCP_METRICS_ATTR_VALS];
+ if (a) {
+ struct rtattr *m[TCP_METRIC_MAX + 1 + 1];
+
+ parse_rtattr_nested(m, TCP_METRIC_MAX + 1, a);
+
+ for (i = 0; i < TCP_METRIC_MAX + 1; i++) {
+ __u32 val;
+
+ a = m[i + 1];
+ if (!a)
+ continue;
+ if (metric_name[i])
+ fprintf(fp, " %s ", metric_name[i]);
+ else
+ fprintf(fp, " metric_%d ", i);
+ val = rta_getattr_u32(a);
+ switch (i) {
+ case TCP_METRIC_RTT:
+ fprintf(fp, "%lluus", (val * 1000ULL) >> 3);
+ break;
+ case TCP_METRIC_RTTVAR:
+ fprintf(fp, "%lluus", (val * 1000ULL) >> 2);
+ break;
+ case TCP_METRIC_SSTHRESH:
+ case TCP_METRIC_CWND:
+ case TCP_METRIC_REORDERING:
+ default:
+ fprintf(fp, "%u", val);
+ break;
+ }
+ }
+ }
+
+ a = attrs[TCP_METRICS_ATTR_FOPEN_MSS];
+ if (a)
+ fprintf(fp, " fo_mss %u", rta_getattr_u16(a));
+
+ a = attrs[TCP_METRICS_ATTR_FOPEN_SYN_DROPS];
+ if (a) {
+ __u16 syn_loss = rta_getattr_u16(a);
+ __u64 ts;
+
+ a = attrs[TCP_METRICS_ATTR_FOPEN_SYN_DROP_TS];
+ ts = a ? rta_getattr_u64(a) : 0;
+
+ fprintf(fp, " fo_syn_drops %u/%llu.%03llusec ago",
+ syn_loss, ts / 1000, ts % 1000);
+ }
+
+ a = attrs[TCP_METRICS_ATTR_FOPEN_COOKIE];
+ if (a) {
+ char cookie[32 + 1];
+ unsigned char *ptr = RTA_DATA(a);
+ int i, max = RTA_PAYLOAD(a);
+
+ if (max > 16)
+ max = 16;
+ cookie[0] = 0;
+ for (i = 0; i < max; i++)
+ sprintf(cookie + i + i, "%02x", ptr[i]);
+ fprintf(fp, " fo_cookie %s", cookie);
+ }
+
+ fprintf(fp, "\n");
+
+ fflush(fp);
+ return 0;
+}
+
+static int tcpm_do_cmd(int cmd, int argc, char **argv)
+{
+ TCPM_REQUEST(req, 1024, TCP_METRICS_CMD_GET, NLM_F_REQUEST);
+ int atype = -1;
+ int ack;
+
+ memset(&f, 0, sizeof(f));
+ f.addr.bitlen = -1;
+ f.addr.family = preferred_family;
+
+ switch (preferred_family) {
+ case AF_UNSPEC:
+ case AF_INET:
+ case AF_INET6:
+ break;
+ default:
+ fprintf(stderr, "Unsupported family:%d\n", preferred_family);
+ return -1;
+ }
+
+ for (; argc > 0; argc--, argv++) {
+ char *who = "address";
+
+ if (strcmp(*argv, "addr") == 0 ||
+ strcmp(*argv, "address") == 0) {
+ who = *argv;
+ NEXT_ARG();
+ }
+ if (matches(*argv, "help") == 0)
+ usage();
+ if (f.addr.bitlen >= 0)
+ duparg2(who, *argv);
+
+ get_prefix(&f.addr, *argv, preferred_family);
+ if (f.addr.bytelen && f.addr.bytelen * 8 == f.addr.bitlen) {
+ if (f.addr.family == AF_INET)
+ atype = TCP_METRICS_ATTR_ADDR_IPV4;
+ else if (f.addr.family == AF_INET6)
+ atype = TCP_METRICS_ATTR_ADDR_IPV6;
+ }
+ if ((CMD_DEL & cmd) && atype < 0) {
+ fprintf(stderr, "Error: a specific IP address is expected rather than \"%s\"\n",
+ *argv);
+ return -1;
+ }
+
+ argc--; argv++;
+ }
+
+ if (cmd == CMD_DEL && atype < 0)
+ missarg("address");
+
+ /* flush for exact address ? Single del */
+ if (cmd == CMD_FLUSH && atype >= 0)
+ cmd = CMD_DEL;
+
+ /* flush for all addresses ? Single del without address */
+ if (cmd == CMD_FLUSH && f.addr.bitlen <= 0 &&
+ preferred_family == AF_UNSPEC) {
+ cmd = CMD_DEL;
+ req.g.cmd = TCP_METRICS_CMD_DEL;
+ ack = 1;
+ } else if (cmd == CMD_DEL) {
+ req.g.cmd = TCP_METRICS_CMD_DEL;
+ ack = 1;
+ } else { /* CMD_FLUSH, CMD_LIST */
+ ack = 0;
+ }
+
+ if (genl_family < 0) {
+ if (rtnl_open_byproto(&grth, 0, NETLINK_GENERIC) < 0) {
+ fprintf(stderr, "Cannot open generic netlink socket\n");
+ exit(1);
+ }
+ genl_family = genl_resolve_family(&grth,
+ TCP_METRICS_GENL_NAME);
+ if (genl_family < 0)
+ exit(1);
+ req.n.nlmsg_type = genl_family;
+ }
+
+ if (!(cmd & CMD_FLUSH) && (atype >= 0 || (cmd & CMD_DEL))) {
+ if (ack)
+ req.n.nlmsg_flags |= NLM_F_ACK;
+ if (atype >= 0)
+ addattr_l(&req.n, sizeof(req), atype, &f.addr.data,
+ f.addr.bytelen);
+ } else {
+ req.n.nlmsg_flags |= NLM_F_DUMP;
+ }
+
+ f.cmd = cmd;
+ if (cmd & CMD_FLUSH) {
+ int round = 0;
+ char flushb[4096-512];
+
+ f.flushb = flushb;
+ f.flushp = 0;
+ f.flushe = sizeof(flushb);
+
+ for (;;) {
+ req.n.nlmsg_seq = grth.dump = ++grth.seq;
+ if (rtnl_send(&grth, &req, req.n.nlmsg_len) < 0) {
+ perror("Failed to send flush request");
+ exit(1);
+ }
+ f.flushed = 0;
+ if (rtnl_dump_filter(&grth, process_msg, stdout) < 0) {
+ fprintf(stderr, "Flush terminated\n");
+ exit(1);
+ }
+ if (f.flushed == 0) {
+ if (round == 0) {
+ fprintf(stderr, "Nothing to flush.\n");
+ } else if (show_stats)
+ printf("*** Flush is complete after %d round%s ***\n",
+ round, round > 1 ? "s" : "");
+ fflush(stdout);
+ return 0;
+ }
+ round++;
+ if (flush_update() < 0)
+ exit(1);
+ if (show_stats) {
+ printf("\n*** Round %d, deleting %d entries ***\n",
+ round, f.flushed);
+ fflush(stdout);
+ }
+ }
+ return 0;
+ }
+
+ if (ack) {
+ if (rtnl_talk(&grth, &req.n, 0, 0, NULL) < 0)
+ return -2;
+ } else if (atype >= 0) {
+ if (rtnl_talk(&grth, &req.n, 0, 0, &req.n) < 0)
+ return -2;
+ if (process_msg(NULL, &req.n, stdout) < 0) {
+ fprintf(stderr, "Dump terminated\n");
+ exit(1);
+ }
+ } else {
+ req.n.nlmsg_seq = grth.dump = ++grth.seq;
+ if (rtnl_send(&grth, &req, req.n.nlmsg_len) < 0) {
+ perror("Failed to send dump request");
+ exit(1);
+ }
+
+ if (rtnl_dump_filter(&grth, process_msg, stdout) < 0) {
+ fprintf(stderr, "Dump terminated\n");
+ exit(1);
+ }
+ }
+ return 0;
+}
+
+int do_tcp_metrics(int argc, char **argv)
+{
+ int i;
+
+ if (argc < 1)
+ return tcpm_do_cmd(CMD_LIST, 0, NULL);
+ for (i = 0; i < ARRAY_SIZE(cmds); i++) {
+ if (matches(argv[0], cmds[i].name) == 0)
+ return tcpm_do_cmd(cmds[i].code, argc-1, argv+1);
+ }
+ if (matches(argv[0], "help") == 0)
+ usage();
+
+ fprintf(stderr, "Command \"%s\" is unknown, "
+ "try \"ip tcp_metrics help\".\n", *argv);
+ exit(-1);
+}
+
--- /dev/null
+.TH "IP\-TCP_METRICS" 8 "23 Aug 2012" "iproute2" "Linux"
+.SH "NAME"
+ip-tcp_metrics \- management for TCP Metrics
+.SH "SYNOPSIS"
+.sp
+.ad l
+.in +8
+.ti -8
+.B ip
+.RI "[ " OPTIONS " ]"
+.B tcp_metrics
+.RI "{ " COMMAND " | "
+.BR help " }"
+.sp
+
+.ti -8
+.BR "ip tcp_metrics" " { " show " | " flush " }
+.IR SELECTOR
+
+.ti -8
+.BR "ip tcp_metrics delete " [ " address " ]
+.IR ADDRESS
+
+.ti -8
+.IR SELECTOR " := "
+.RB "[ [ " address " ] "
+.IR PREFIX " ]"
+
+.SH "DESCRIPTION"
+.B ip tcp_metrics
+is used to manipulate entries in the kernel that keep TCP information
+for IPv4 and IPv6 destinations. The entries are created when
+TCP sockets want to share information for destinations and are
+stored in a cache keyed by the destination address. The saved
+information may include values for metrics (initially obtained from
+routes), recent TSVAL for TIME-WAIT recycling purposes, state for the
+Fast Open feature, etc.
+For performance reasons the cache can not grow above configured limit
+and the older entries are replaced with fresh information, sometimes
+reclaimed and used for new destinations. The kernel never removes
+entries, they can be flushed only with this tool.
+
+.SS ip tcp_metrics show - show cached entries
+
+.TP
+.BI address " PREFIX " (default)
+IPv4/IPv6 prefix or address. If no prefix is provided all entries are shown.
+
+.LP
+The output may contain the following information:
+
+.BI age " <S.MMM>" sec
+- time after the entry was created, reset or updated with metrics
+from sockets. The entry is reset and refreshed on use with metrics from
+route if the metrics are not updated in last hour. Not all cached values
+reset the age on update.
+
+.BI cwnd " <N>"
+- CWND metric value
+
+.BI fo_cookie " <HEX-STRING>"
+- Cookie value received in SYN-ACK to be used by Fast Open for next SYNs
+
+.BI fo_mss " <N>"
+- MSS value received in SYN-ACK to be used by Fast Open for next SYNs
+
+.BI fo_syn_drops " <N>/<S.MMM>" "sec ago"
+- Number of drops of initial outgoing Fast Open SYNs with data
+detected by monitoring the received SYN-ACK after SYN retransmission.
+The seconds show the time after last SYN drop and together with
+the drop count can be used to disable Fast Open for some time.
+
+.BI reordering " <N>"
+- Reordering metric value
+
+.BI rtt " <N>" us
+- RTT metric value
+
+.BI rttvar " <N>" us
+- RTTVAR metric value
+
+.BI ssthresh " <SSTHRESH>"
+- SSTHRESH metric value
+
+.BI tw_ts " <TSVAL>/<SEC>" "sec ago"
+- recent TSVAL and the seconds after saving it into TIME-WAIT socket
+
+.SS ip tcp_metrics delete - delete single entry
+
+.TP
+.BI address " ADDRESS " (default)
+IPv4/IPv6 address. The address is a required argument.
+
+.SS ip tcp_metrics flush - flush entries
+This command flushes the entries selected by some criteria.
+
+.PP
+This command has the same arguments as
+.B show.
+
+.SH "EXAMPLES"
+.PP
+ip tcp_metrics show address 192.168.0.0/24
+.RS 4
+Shows the entries for destinations from subnet
+.RE
+.PP
+ip tcp_metrics show 192.168.0.0/24
+.RS 4
+The same but address keyword is optional
+.RE
+.PP
+ip tcp_metrics
+.RS 4
+Show all is the default action
+.RE
+.PP
+ip tcp_metrics delete 192.168.0.1
+.RS 4
+Removes the entry for 192.168.0.1 from cache.
+.RE
+.PP
+ip tcp_metrics flush 192.168.0.0/24
+.RS 4
+Removes entries for destinations from subnet
+.RE
+.PP
+ip tcp_metrics flush all
+.RS 4
+Removes all entries from cache
+.RE
+.PP
+ip -6 tcp_metrics flush all
+.RS 4
+Removes all IPv6 entries from cache keeping the IPv4 entries.
+.RE
+
+.SH SEE ALSO
+.br
+.BR ip (8)
+
+.SH AUTHOR
+Original Manpage by Julian Anastasov <ja@ssi.bg>
projects / thirdparty / iproute2.git / commitdiff
