ss: allow dumping MPTCP subflow information

 [root@f31 packetdrill]# ss -tni

 ESTAB    0        0           192.168.82.247:8080           192.0.2.1:35273
          cubic wscale:7,8 [...] tcp-ulp-mptcp flags:Mec token:0000(id:0)/5f856c60(id:0) seq:b810457db34209a5 sfseq:1 ssnoff:0 maplen:190

Additionally extends ss manpage to describe the new entry layout.

Signed-off-by: Davide Caratti <dcaratti@redhat.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: David Ahern <dsahern@gmail.com>

diff --git a/man/man8/ss.8 b/man/man8/ss.8
index 023d771b17878091d036159d6b796e931f44a233..c80853f98c49ad22fe9839a93f23e808ca4c2319 100644 (file)
--- a/man/man8/ss.8
+++ b/man/man8/ss.8
@@ -261,6 +261,11 @@ the pacing rate and max pacing rate
 .TP
 .B rcv_space:<rcv_space>
 a helper variable for TCP internal auto tuning socket receive buffer
+.P
+.TP
+.B tcp-ulp-mptcp flags:[MmBbJjecv] token:<rem_token(rem_id)/loc_token(loc_id)> seq:<sn> sfseq:<ssn> ssnoff:<off> maplen:<maplen>
+MPTCP subflow information
+.P
 .RE
 .TP
 .B \-\-tos

diff --git a/misc/ss.c b/misc/ss.c
index 3ef151fbf1f1b3856e95a1baa751a1cdd27d10b7..ee840149b5f045469d0b42b85dd64063b2f17f9e 100644 (file)
--- a/misc/ss.c
+++ b/misc/ss.c
@@ -53,6 +53,7 @@
 #include <linux/tipc_netlink.h>
 #include <linux/tipc_sockets_diag.h>
 #include <linux/tls.h>
+#include <linux/mptcp.h>
 
 /* AF_VSOCK/PF_VSOCK is only provided since glibc 2.18 */
 #ifndef PF_VSOCK
@@ -2836,6 +2837,59 @@ static void tcp_tls_conf(const char *name, struct rtattr *attr)
        }
 }
 
+static void mptcp_subflow_info(struct rtattr *tb[])
+{
+       u_int32_t flags = 0;
+
+       if (tb[MPTCP_SUBFLOW_ATTR_FLAGS]) {
+               char caps[32 + 1] = { 0 }, *cap = &caps[0];
+
+               flags = rta_getattr_u32(tb[MPTCP_SUBFLOW_ATTR_FLAGS]);
+
+               if (flags & MPTCP_SUBFLOW_FLAG_MCAP_REM)
+                       *cap++ = 'M';
+               if (flags & MPTCP_SUBFLOW_FLAG_MCAP_LOC)
+                       *cap++ = 'm';
+               if (flags & MPTCP_SUBFLOW_FLAG_JOIN_REM)
+                       *cap++ = 'J';
+               if (flags & MPTCP_SUBFLOW_FLAG_JOIN_LOC)
+                       *cap++ = 'j';
+               if (flags & MPTCP_SUBFLOW_FLAG_BKUP_REM)
+                       *cap++ = 'B';
+               if (flags & MPTCP_SUBFLOW_FLAG_BKUP_LOC)
+                       *cap++ = 'b';
+               if (flags & MPTCP_SUBFLOW_FLAG_FULLY_ESTABLISHED)
+                       *cap++ = 'e';
+               if (flags & MPTCP_SUBFLOW_FLAG_CONNECTED)
+                       *cap++ = 'c';
+               if (flags & MPTCP_SUBFLOW_FLAG_MAPVALID)
+                       *cap++ = 'v';
+               if (flags)
+                       out(" flags:%s", caps);
+       }
+       if (tb[MPTCP_SUBFLOW_ATTR_TOKEN_REM] &&
+           tb[MPTCP_SUBFLOW_ATTR_TOKEN_LOC] &&
+           tb[MPTCP_SUBFLOW_ATTR_ID_REM] &&
+           tb[MPTCP_SUBFLOW_ATTR_ID_LOC])
+               out(" token:%04x(id:%hhu)/%04x(id:%hhu)",
+                   rta_getattr_u32(tb[MPTCP_SUBFLOW_ATTR_TOKEN_REM]),
+                   rta_getattr_u8(tb[MPTCP_SUBFLOW_ATTR_ID_REM]),
+                   rta_getattr_u32(tb[MPTCP_SUBFLOW_ATTR_TOKEN_LOC]),
+                   rta_getattr_u8(tb[MPTCP_SUBFLOW_ATTR_ID_LOC]));
+       if (tb[MPTCP_SUBFLOW_ATTR_MAP_SEQ])
+               out(" seq:%llx",
+                   rta_getattr_u64(tb[MPTCP_SUBFLOW_ATTR_MAP_SEQ]));
+       if (tb[MPTCP_SUBFLOW_ATTR_MAP_SFSEQ])
+               out(" sfseq:%x",
+                   rta_getattr_u32(tb[MPTCP_SUBFLOW_ATTR_MAP_SFSEQ]));
+       if (tb[MPTCP_SUBFLOW_ATTR_SSN_OFFSET])
+               out(" ssnoff:%x",
+                   rta_getattr_u32(tb[MPTCP_SUBFLOW_ATTR_SSN_OFFSET]));
+       if (tb[MPTCP_SUBFLOW_ATTR_MAP_DATALEN])
+               out(" maplen:%x",
+                   rta_getattr_u32(tb[MPTCP_SUBFLOW_ATTR_MAP_DATALEN]));
+}
+
 #define TCPI_HAS_OPT(info, opt) !!(info->tcpi_options & (opt))
 
 static void tcp_show_info(const struct nlmsghdr *nlh, struct inet_diag_msg *r,
@@ -3012,6 +3066,14 @@ static void tcp_show_info(const struct nlmsghdr *nlh, struct inet_diag_msg *r,
                        tcp_tls_conf("rxconf", tlsinfo[TLS_INFO_RXCONF]);
                        tcp_tls_conf("txconf", tlsinfo[TLS_INFO_TXCONF]);
                }
+               if (ulpinfo[INET_ULP_INFO_MPTCP]) {
+                       struct rtattr *sfinfo[MPTCP_SUBFLOW_ATTR_MAX + 1] =
+                               { 0 };
+
+                       parse_rtattr_nested(sfinfo, MPTCP_SUBFLOW_ATTR_MAX,
+                                           ulpinfo[INET_ULP_INFO_MPTCP]);
+                       mptcp_subflow_info(sfinfo);
+               }
        }
 }