inet_diag: properly deal with INADDR_ANY binds

Oops :x  This was totally broken with the all-listener
filter.

1 files changed, 53 insertions, 12 deletions

diff --git a/ext/raindrops/linux_inet_diag.c b/ext/raindrops/linux_inet_diag.c
index feb51d9..f43a8c9 100644
--- a/ext/raindrops/linux_inet_diag.c
+++ b/ext/raindrops/linux_inet_diag.c
@@ -132,9 +132,28 @@ static int st_AND_hash(st_data_t key, st_data_t value, VALUE hash)
         return st_free_data(key, value, 0);
 }
 
+static const char *addr_any(sa_family_t family)
+{
+        static const char ipv4[] = "0.0.0.0";
+        static const char ipv6[] = "[::]";
+
+        if (family == AF_INET)
+                return ipv4;
+        assert(family == AF_INET6 && "unknown family");
+        return ipv6;
+}
+
+static void bug_warn(void)
+{
+        fprintf(stderr, "Please report how you produced this at "\
+                        "raindrops@librelist.com\n");
+        fflush(stderr);
+}
+
 static struct listen_stats *stats_for(st_table *table, struct inet_diag_msg *r)
 {
-        char *key, *port;
+        char *key, *port, *old_key;
+        size_t alloca_len;
         struct listen_stats *stats;
         size_t keylen;
         size_t portlen = sizeof("65535");
@@ -146,15 +165,16 @@ static struct listen_stats *stats_for(st_table *table, struct inet_diag_msg *r)
         switch ((ss.ss_family = r->idiag_family)) {
         case AF_INET: {
                 struct sockaddr_in *in = (struct sockaddr_in *)&ss;
+
                 in->sin_port = r->id.idiag_sport;
                 in->sin_addr.s_addr = r->id.idiag_src[0];
                 keylen = INET_ADDRSTRLEN;
-                key = alloca(keylen + 1 + portlen);
+                alloca_len = keylen + 1 + portlen;
+                key = alloca(alloca_len);
                 key[keylen] = 0; /* will be ':' later */
                 port = key + keylen + 1;
                 rc = getnameinfo((struct sockaddr *)&ss, len,
                                  key, keylen, port, portlen, flags);
-
                 break;
                 }
         case AF_INET6: {
@@ -164,7 +184,8 @@ static struct listen_stats *stats_for(st_table *table, struct inet_diag_msg *r)
                        &r->id.idiag_src, sizeof(__be32[4]));
                 keylen = INET6_ADDRSTRLEN;
                           /* [            ] */
-                key = alloca(1 + keylen + 1 + 1 + portlen);
+                alloca_len = 1 + keylen + 1 + 1 + portlen;
+                key = alloca(alloca_len);
                 *key = '[';
                 key[1 + keylen + 1] = 0; /* will be ':' later */
                 port = 1 + key + keylen + 1 + 1;
@@ -176,10 +197,8 @@ static struct listen_stats *stats_for(st_table *table, struct inet_diag_msg *r)
                 assert(0 && "unsupported address family, could that be IPv7?!");
         }
         if (rc != 0) {
-                fprintf(stderr, "BUG: getnameinfo: %s\n"
-                        "Please report how you produced this at %s\n",
-                        gai_strerror(rc), "raindrops@librelist.com");
-                fflush(stderr);
+                fprintf(stderr, "BUG: getnameinfo: %s\n", gai_strerror(rc));
+                bug_warn();
                 *key = 0;
         }
 
@@ -195,19 +214,41 @@ static struct listen_stats *stats_for(st_table *table, struct inet_diag_msg *r)
                 key[keylen] = ']';
                 key[keylen + 1] = ':';
                 memmove(key + keylen + 2, port, portlen + 1);
+                keylen++;
                 break;
         default:
                 assert(0 && "unsupported address family, could that be IPv7?!");
         }
 
-        if (!st_lookup(table, (st_data_t)key, (st_data_t *)&stats)) {
-                char *old_key = key;
+        if (st_lookup(table, (st_data_t)key, (st_data_t *)&stats))
+                return stats;
+
+        old_key = key;
 
+        if (r->idiag_state == TCP_ESTABLISHED) {
+                int n = snprintf(key, alloca_len, "%s:%u",
+                                 addr_any(ss.ss_family),
+                                 ntohs(r->id.idiag_sport));
+                if (n <= 0) {
+                        fprintf(stderr, "BUG: snprintf: %d\n", n);
+                        bug_warn();
+                }
+                if (st_lookup(table, (st_data_t)key, (st_data_t *)&stats))
+                        return stats;
+                if (n <= 0) {
+                        key = xmalloc(1);
+                        *key = '\0';
+                } else {
+                        old_key = key;
+                        key = xmalloc(n + 1);
+                        memcpy(key, old_key, n + 1);
+                }
+        } else {
                 key = xmalloc(keylen + 1 + portlen + 1);
                 memcpy(key, old_key, keylen + 1 + portlen + 1);
-                stats = xcalloc(1, sizeof(struct listen_stats));
-                st_insert(table, (st_data_t)key, (st_data_t)stats);
         }
+        stats = xcalloc(1, sizeof(struct listen_stats));
+        st_insert(table, (st_data_t)key, (st_data_t)stats);
         return stats;
 }