[PATCH iproute2-next] ss: always prefer family as part of host condition to default family

[Thayne McCombs]

ss accepts an address family both with the -f option and as part of a
host condition. However, if the family in the host condition is
different than the the last -f option, then which family is actually
used depends on the order that different families are checked.

This changes parse_hostcond to check all family prefixes before parsing
the rest of the address, so that the host condition's family always has
a higher priority than the "preferred" family.

Signed-off-by: Thayne McCombs <astrotha...@gmail.com>
---
 misc/ss.c | 50 ++++++++++++++++++++++++--------------------------
 1 file changed, 24 insertions(+), 26 deletions(-)

diff --git a/misc/ss.c b/misc/ss.c
index 0593627b..2a5e056a 100644
--- a/misc/ss.c
+++ b/misc/ss.c
@@ -2119,24 +2119,39 @@ void *parse_hostcond(char *addr, bool is_port)
        int fam = preferred_family;
        struct filter *f = &current_filter;
 
-       if (fam == AF_UNIX || strncmp(addr, "unix:", 5) == 0) {
+    if (strncmp(addr, "unix:", 5) == 0) {
+        fam = AF_UNIX;
+        addr += 5;
+    } else if (strncmp(addr, "link:", 5) == 0) {
+        fam = AF_PACKET;
+        addr += 5;
+    } else if (strncmp(addr, "netlink:", 8) == 0) {
+        fam = AF_NETLINK;
+        addr += 8;
+    } else if (strncmp(addr, "vsock:", 6) == 0) {
+        fam = AF_VSOCK;
+        addr += 6;
+    } else if (strncmp(addr, "inet:", 5) == 0) {
+        fam = AF_INET;
+        addr += 5;
+    } else if (strncmp(addr, "inet6:", 6) == 0) {
+        fam = AF_INET6;
+        addr += 6;
+    }
+
+       if (fam == AF_UNIX) {
                char *p;
 
                a.addr.family = AF_UNIX;
-               if (strncmp(addr, "unix:", 5) == 0)
-                       addr += 5;
                p = strdup(addr);
                a.addr.bitlen = 8*strlen(p);
                memcpy(a.addr.data, &p, sizeof(p));
-               fam = AF_UNIX;
                goto out;
        }
 
-       if (fam == AF_PACKET || strncmp(addr, "link:", 5) == 0) {
+       if (fam == AF_PACKET) {
                a.addr.family = AF_PACKET;
                a.addr.bitlen = 0;
-               if (strncmp(addr, "link:", 5) == 0)
-                       addr += 5;
                port = strchr(addr, ':');
                if (port) {
                        *port = 0;
@@ -2155,15 +2170,12 @@ void *parse_hostcond(char *addr, bool is_port)
                                return NULL;
                        a.addr.data[0] = ntohs(tmp);
                }
-               fam = AF_PACKET;
                goto out;
        }
 
-       if (fam == AF_NETLINK || strncmp(addr, "netlink:", 8) == 0) {
+       if (fam == AF_NETLINK) {
                a.addr.family = AF_NETLINK;
                a.addr.bitlen = 0;
-               if (strncmp(addr, "netlink:", 8) == 0)
-                       addr += 8;
                port = strchr(addr, ':');
                if (port) {
                        *port = 0;
@@ -2181,16 +2193,13 @@ void *parse_hostcond(char *addr, bool is_port)
                        if (nl_proto_a2n(&a.addr.data[0], addr) == -1)
                                return NULL;
                }
-               fam = AF_NETLINK;
                goto out;
        }
 
-       if (fam == AF_VSOCK || strncmp(addr, "vsock:", 6) == 0) {
+       if (fam == AF_VSOCK) {
                __u32 cid = ~(__u32)0;
 
                a.addr.family = AF_VSOCK;
-               if (strncmp(addr, "vsock:", 6) == 0)
-                       addr += 6;
 
                if (is_port)
                        port = addr;
@@ -2212,20 +2221,9 @@ void *parse_hostcond(char *addr, bool is_port)
                                return NULL;
                }
                vsock_set_inet_prefix(&a.addr, cid);
-               fam = AF_VSOCK;
                goto out;
        }
 
-       if (fam == AF_INET || !strncmp(addr, "inet:", 5)) {
-               fam = AF_INET;
-               if (!strncmp(addr, "inet:", 5))
-                       addr += 5;
-       } else if (fam == AF_INET6 || !strncmp(addr, "inet6:", 6)) {
-               fam = AF_INET6;
-               if (!strncmp(addr, "inet6:", 6))
-                       addr += 6;
-       }
-
        /* URL-like literal [] */
        if (addr[0] == '[') {
                addr++;
-- 
2.30.0