Use net_pack instead of casting bytes to ints.

The current code violates the C standard and causes crashes on strict alignment architectures.
TokTok · Mar 6, 2020 · 7b3d2ed · 7b3d2ed
1 parent 7923a61
commit 7b3d2ed
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Showing 3 changed files with 25 additions and 15 deletions.
diff --git a/toxav/bwcontroller.c b/toxav/bwcontroller.c
@@ -146,12 +146,16 @@ void send_update(BWController *bwc)
                          (void *)bwc, bwc->cycle.recv, bwc->cycle.lost,
                          (((double) bwc->cycle.lost / (bwc->cycle.recv + bwc->cycle.lost)) * 100.0));
             uint8_t bwc_packet[sizeof(struct BWCMessage) + 1];
-            struct BWCMessage *msg = (struct BWCMessage *)(bwc_packet + 1);
-            bwc_packet[0] = BWC_PACKET_ID; // set packet ID
-            msg->lost = net_htonl(bwc->cycle.lost);
-            msg->recv = net_htonl(bwc->cycle.recv);
+            size_t offset = 0;
 
-            if (-1 == m_send_custom_lossy_packet(bwc->m, bwc->friend_number, bwc_packet, sizeof(bwc_packet))) {
+            bwc_packet[offset] = BWC_PACKET_ID; // set packet ID
+            ++offset;
+
+            offset += net_pack_u32(bwc_packet + offset, bwc->cycle.lost);
+            offset += net_pack_u32(bwc_packet + offset, bwc->cycle.recv);
+            assert(offset == sizeof(bwc_packet));
+
+            if (m_send_custom_lossy_packet(bwc->m, bwc->friend_number, bwc_packet, sizeof(bwc_packet)) == -1) {
                 const char *netstrerror = net_new_strerror(net_error());
                 LOGGER_WARNING(bwc->m->log, "BWC send failed (len: %u)! std error: %s, net error %s",
                                (unsigned)sizeof(bwc_packet), strerror(errno), netstrerror);
@@ -177,8 +181,8 @@ static int on_update(BWController *bwc, const struct BWCMessage *msg)
 
     bwc->cycle.last_recv_timestamp = current_time_monotonic(bwc->m->mono_time);
 
-    uint32_t recv = net_ntohl(msg->recv);
-    uint32_t lost = net_ntohl(msg->lost);
+    const uint32_t recv = msg->recv;
+    const uint32_t lost = msg->lost;
 
     if (lost && bwc->mcb) {
         LOGGER_DEBUG(bwc->m->log, "recved: %u lost: %u percentage: %f %%", recv, lost,
@@ -197,5 +201,11 @@ int bwc_handle_data(Messenger *m, uint32_t friendnumber, const uint8_t *data, ui
         return -1;
     }
 
-    return on_update((BWController *)object, (const struct BWCMessage *)(data + 1));
+    size_t offset = 1;  // Ignore packet id.
+    struct BWCMessage msg;
+    offset += net_unpack_u32(data + offset, &msg.lost);
+    offset += net_unpack_u32(data + offset, &msg.recv);
+    assert(offset == length);
+
+    return on_update((BWController *)object, &msg);
 }
diff --git a/toxcore/LAN_discovery.c b/toxcore/LAN_discovery.c
@@ -186,7 +186,7 @@ static void fetch_broadcast_info(uint16_t port)
             continue;
         }
 
-        struct sockaddr_in *sock4 = (struct sockaddr_in *)&i_faces[i].ifr_broadaddr;
+        struct sockaddr_in *sock4 = (struct sockaddr_in *)(void *)&i_faces[i].ifr_broadaddr;
 
         if (count >= MAX_INTERFACES) {
             break;

diff --git a/toxcore/network.c b/toxcore/network.c
@@ -1207,12 +1207,12 @@ int addr_resolve(const char *address, IP *to, IP *extra)
         switch (walker->ai_family) {
             case AF_INET:
                 if (walker->ai_family == family) { /* AF_INET requested, done */
-                    struct sockaddr_in *addr = (struct sockaddr_in *)walker->ai_addr;
+                    struct sockaddr_in *addr = (struct sockaddr_in *)(void *)walker->ai_addr;
                     get_ip4(&to->ip.v4, &addr->sin_addr);
                     result = TOX_ADDR_RESOLVE_INET;
                     done = 1;
                 } else if (!(result & TOX_ADDR_RESOLVE_INET)) { /* AF_UNSPEC requested, store away */
-                    struct sockaddr_in *addr = (struct sockaddr_in *)walker->ai_addr;
+                    struct sockaddr_in *addr = (struct sockaddr_in *)(void *)walker->ai_addr;
                     get_ip4(&ip4.ip.v4, &addr->sin_addr);
                     result |= TOX_ADDR_RESOLVE_INET;
                 }
@@ -1222,14 +1222,14 @@ int addr_resolve(const char *address, IP *to, IP *extra)
             case AF_INET6:
                 if (walker->ai_family == family) { /* AF_INET6 requested, done */
                     if (walker->ai_addrlen == sizeof(struct sockaddr_in6)) {
-                        struct sockaddr_in6 *addr = (struct sockaddr_in6 *)walker->ai_addr;
+                        struct sockaddr_in6 *addr = (struct sockaddr_in6 *)(void *)walker->ai_addr;
                         get_ip6(&to->ip.v6, &addr->sin6_addr);
                         result = TOX_ADDR_RESOLVE_INET6;
                         done = 1;
                     }
                 } else if (!(result & TOX_ADDR_RESOLVE_INET6)) { /* AF_UNSPEC requested, store away */
                     if (walker->ai_addrlen == sizeof(struct sockaddr_in6)) {
-                        struct sockaddr_in6 *addr = (struct sockaddr_in6 *)walker->ai_addr;
+                        struct sockaddr_in6 *addr = (struct sockaddr_in6 *)(void *)walker->ai_addr;
                         get_ip6(&ip6.ip.v6, &addr->sin6_addr);
                         result |= TOX_ADDR_RESOLVE_INET6;
                     }
@@ -1344,10 +1344,10 @@ int32_t net_getipport(const char *node, IP_Port **res, int tox_type)
         }
 
         if (cur->ai_family == AF_INET) {
-            struct sockaddr_in *addr = (struct sockaddr_in *)cur->ai_addr;
+            struct sockaddr_in *addr = (struct sockaddr_in *)(void *)cur->ai_addr;
             memcpy(&ip_port->ip.ip.v4, &addr->sin_addr, sizeof(IP4));
         } else if (cur->ai_family == AF_INET6) {
-            struct sockaddr_in6 *addr = (struct sockaddr_in6 *)cur->ai_addr;
+            struct sockaddr_in6 *addr = (struct sockaddr_in6 *)(void *)cur->ai_addr;
             memcpy(&ip_port->ip.ip.v6, &addr->sin6_addr, sizeof(IP6));
         } else {
             continue;