ss: prepare rth when killing inet sock

kill_inet_sock() expects rhn_handle instance is passed
via inet_diag_arg argument. However on the following calling path:

    generic_show_sock
    => show_one_inet_sock
       => kill_inet_sock

rth field of inet_diag_arg is not filled with the address of
rhn_handle instance. As the result ss crashes.

This commit fills the field with newly created rhn_handle
instance.

Changes in v2:
Instead of creating rtn_handle instances for each socket, create
one in upper layer and reuse it.

Signed-off-by: Masatake YAMATO <yamato@redhat.com>
Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>

diff --git a/misc/ss.c b/misc/ss.c
index 29a250704c2dd46d3235122dcee5dacc41c3fe0d..e047f9c04582fc66a8fe4b2163d50d3781b645a9 100644 (file)
--- a/misc/ss.c
+++ b/misc/ss.c
@@ -239,6 +239,7 @@ struct filter {
        uint64_t families;
        struct ssfilter *f;
        bool kill;
+       struct rtnl_handle *rth_for_killing;
 };
 
 #define FAMILY_MASK(family) ((uint64_t)1 << (family))
@@ -4262,6 +4263,7 @@ static int generic_show_sock(const struct sockaddr_nl *addr,
        switch (r->sdiag_family) {
        case AF_INET:
        case AF_INET6:
+               inet_arg.rth = inet_arg.f->rth_for_killing;
                return show_one_inet_sock(addr, nlh, &inet_arg);
        case AF_UNIX:
                return unix_show_sock(addr, nlh, arg);
@@ -4280,7 +4282,7 @@ static int handle_follow_request(struct filter *f)
 {
        int ret = 0;
        int groups = 0;
-       struct rtnl_handle rth;
+       struct rtnl_handle rth, rth2;
 
        if (f->families & FAMILY_MASK(AF_INET) && f->dbs & (1 << TCP_DB))
                groups |= 1 << (SKNLGRP_INET_TCP_DESTROY - 1);
@@ -4300,10 +4302,20 @@ static int handle_follow_request(struct filter *f)
        rth.dump = 0;
        rth.local.nl_pid = 0;
 
+       if (f->kill) {
+               if (rtnl_open_byproto(&rth2, groups, NETLINK_SOCK_DIAG)) {
+                       rtnl_close(&rth);
+                       return -1;
+               }
+               f->rth_for_killing = &rth2;
+       }
+
        if (rtnl_dump_filter(&rth, generic_show_sock, f))
                ret = -1;
 
        rtnl_close(&rth);
+       if (f->rth_for_killing)
+               rtnl_close(f->rth_for_killing);
        return ret;
 }