Changeset 3121 for pjproject/trunk

Timestamp:

Mar 26, 2010 5:44:04 AM (15 years ago)

Author:

bennylp

Message:

Ticket #1046: Zeroconf/link-local/ActiveSync IPv4 adress 169.254.x.x may be used on Windows Mobile devices (thanks Jan Boquist for the info)

• add treatment for special IPv4/IPv6 addresses: loopback address and link-local address
• with this treatment, link-local address will only be used if there is no other non-loopback/non-link-local IP addresses, and loopback address will only be used if there's absolutely no other IP address

File:

• pjproject/trunk/pjlib/src/pj/sock_common.c (modified) (4 diffs)

pjproject/trunk/pjlib/src/pj/sock_common.c

@@ -691 +691 @@
 }
 
-static pj_bool_t is_usable_ip(const pj_sockaddr *addr)
-{
-    if (addr->addr.sa_family==PJ_AF_INET) {
-        /* Only consider if the address is not 127.0.0.0/8 or 0.0.0.0/8.
-         * The 0.0.0.0/8 is a special IP class that doesn't seem to be
-         * practically useful for our purpose.
-         */
-        if ((pj_ntohl(addr->ipv4.sin_addr.s_addr)>>24)==127)
-            return PJ_FALSE;
-        if ((pj_ntohl(addr->ipv4.sin_addr.s_addr)>>24)==0)
-            return PJ_FALSE;
-
-        return PJ_TRUE;
-
-    } else if (addr->addr.sa_family==PJ_AF_INET6) {
-        pj_sockaddr ipv6_loop;
-        const pj_str_t loop = { "::1", 3};
-        pj_status_t status;
-
-        status = pj_sockaddr_set_str_addr(PJ_AF_INET6, &ipv6_loop, &loop);
-        if (status != PJ_SUCCESS)
-            return PJ_TRUE;
-
-        if (pj_memcmp(&addr->ipv6.sin6_addr, &ipv6_loop.ipv6.sin6_addr, 16)==0)
-            return PJ_FALSE;
-
-        return PJ_TRUE;
-    } else {
-        return PJ_TRUE;
-    }
-}
-
 /* Resolve the IP address of local machine */
 PJ_DEF(pj_status_t) pj_gethostip(int af, pj_sockaddr *addr)
@@ -729 +697 @@
     enum {
         CAND_CNT = 8,
+
+        /* Weighting to be applied to found addresses */
         WEIGHT_HOSTNAME = 1,    /* hostname IP is not always valid! */
         WEIGHT_DEF_ROUTE = 2,
-        WEIGHT_INTERFACE = 1
+        WEIGHT_INTERFACE = 1,
+        WEIGHT_LOOPBACK = -4,
+        WEIGHT_LINK_LOCAL = -3,
+        WEIGHT_DISABLED = -50,
+
+        MIN_WEIGHT = WEIGHT_DISABLED+1  /* minimum weight to use */
     };
     /* candidates: */
     pj_sockaddr cand_addr[CAND_CNT];
-    unsigned    cand_weight[CAND_CNT];
+    int         cand_weight[CAND_CNT];
     int         selected_cand;
     char        strip[PJ_INET6_ADDRSTRLEN+10];
+    /* Special IPv4 addresses. */
+    struct spec_ipv4_t
+    {
+        pj_uint32_t addr;
+        pj_uint32_t mask;
+        int         weight;
+    } spec_ipv4[] =
+    {
+        /* 127.0.0.0/8, loopback addr will be used if there is no other
+         * addresses.
+         */
+        { 0x7f000000, 0xFF000000, WEIGHT_LOOPBACK },
+
+        /* 0.0.0.0/8, special IP that doesn't seem to be practically useful */
+        { 0x00000000, 0xFF000000, WEIGHT_DISABLED },
+
+        /* 169.254.0.0/16, a zeroconf/link-local address, which has higher
+         * priority than loopback and will be used if there is no other
+         * valid addresses.
+         */
+        { 0xa9fe0000, 0xFFFF0000, WEIGHT_LINK_LOCAL }
+    };
+    /* Special IPv6 addresses */
+    struct spec_ipv6_t
+    {
+        pj_uint8_t addr[16];
+        pj_uint8_t mask[16];
+        int        weight;
+    } spec_ipv6[] =
+    {
+        /* Loopback address, ::1/128 */
+        { {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1},
+          {0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,
+           0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff},
+          WEIGHT_LOOPBACK
+        },
+
+        /* Link local, fe80::/10 */
+        { {0xfe,0x80,0,0,0,0,0,0,0,0,0,0,0,0,0,0},
+          {0xff,0xc0,0,0,0,0,0,0,0,0,0,0,0,0,0,0},
+          WEIGHT_LINK_LOCAL
+        },
+
+        /* Disabled, ::/128 */
+        { {0x0,0x0,0,0,0,0,0,0,0,0,0,0,0,0,0,0},
+        { 0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,
+          0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff},
+          WEIGHT_DISABLED
+        }
+    };
     pj_addrinfo ai;
     pj_status_t status;
@@ -848 +873 @@
     }
 
+    /* Apply weight adjustment for special IPv4/IPv6 addresses
+     * See http://trac.pjsip.org/repos/ticket/1046
+     */
+    if (af == PJ_AF_INET) {
+        for (i=0; i<cand_cnt; ++i) {
+            unsigned j;
+            for (j=0; j<PJ_ARRAY_SIZE(spec_ipv4); ++j) {
+                    pj_uint32_t a = pj_ntohl(cand_addr[i].ipv4.sin_addr.s_addr);
+                    pj_uint32_t pa = spec_ipv4[j].addr;
+                    pj_uint32_t pm = spec_ipv4[j].mask;
+
+                    if ((a & pm) == pa) {
+                        cand_weight[i] += spec_ipv4[j].weight;
+                        break;
+                    }
+            }
+        }
+    } else if (af == PJ_AF_INET6) {
+        for (i=0; i<PJ_ARRAY_SIZE(spec_ipv6); ++i) {
+                unsigned j;
+                for (j=0; j<cand_cnt; ++j) {
+                    pj_uint8_t *a = cand_addr[j].ipv6.sin6_addr.s6_addr;
+                    pj_uint8_t am[16];
+                    pj_uint8_t *pa = spec_ipv6[i].addr;
+                    pj_uint8_t *pm = spec_ipv6[i].mask;
+                    unsigned k;
+
+                    for (k=0; k<16; ++k) {
+                        am[k] = (a[k] & pm[k]) & 0xFF;
+                    }
+
+                    if (pj_memcmp(am, pa, 16)==0) {
+                        cand_weight[j] += spec_ipv6[i].weight;
+                    }
+                }
+        }
+    } else {
+        return PJ_EAFNOTSUP;
+    }
+
     /* Enumerate candidates to get the best IP address to choose */
     selected_cand = -1;
@@ -855 +920 @@
                 cand_weight[i]));
 
-        if (!is_usable_ip(&cand_addr[i])) {
+        if (cand_weight[i] < MIN_WEIGHT) {
             continue;
         }