Fix: wrong size and address type in socks5-udp

EmonLieu · Nov 23, 2019 · 4cc0fef · 4cc0fef
1 parent 3a46f2f
commit 4cc0fef
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Showing 2 changed files with 26 additions and 7 deletions.
diff --git a/socks5-udp.c b/socks5-udp.c
@@ -56,7 +56,7 @@ static struct evbuffer* socks5_mkassociate(void *p)
 }
 
 static void socks5_fill_preamble(
-    socks5_udp_preabmle *preamble,
+       socks5_udp_preamble *preamble,
        struct sockaddr * addr,
        size_t *preamble_len)
 {
@@ -125,11 +125,25 @@ static int socks5_ready_to_fwd(struct redudp_client_t *client)
 static void socks5_forward_pkt(redudp_client *client, struct sockaddr *destaddr, void *buf, size_t pktlen)
 {
     socks5_client *socks5client = (void*)(client + 1);
-    socks5_udp_preabmle req;
+    socks5_udp_preamble req;
     struct msghdr msg;
     struct iovec io[2];
     size_t preamble_len;
 
+    if (socks5client->udprelayaddr.sin_family == AF_INET) {
+        preamble_len = SOCKS5_UDP_PREAMBLE_SIZE_V4;
+    }
+    /*
+    else if (socks5client->udprelayaddr.ss_family == AF_INET6) {
+        preamble_len = SOCKS5_UDP_PREAMBLE_SIZE_V6;
+    }
+    */
+    else {
+        redudp_log_errno(client, LOG_WARNING, "Unknown address type %d",
+                         socks5client->udprelayaddr.sin_family);
+        return;
+    }
+
     socks5_fill_preamble(&req, destaddr, &preamble_len);
 
     ssize_t outgoing, fwdlen = pktlen + preamble_len;
@@ -161,7 +175,7 @@ static void socks5_pkt_from_socks(int fd, short what, void *_arg)
     socks5_client *socks5client = (void*)(client + 1);
     union {
         char buf[MAX_UDP_PACKET_SIZE];
-        socks5_udp_preabmle header;
+        socks5_udp_preamble header;
     } * pkt = client->instance->shared_buff;
     ssize_t pktlen, fwdlen;
     struct sockaddr_storage udprelayaddr;
@@ -172,7 +186,9 @@ static void socks5_pkt_from_socks(int fd, short what, void *_arg)
     if (pktlen == -1)
         return;
 
-    if (memcmp(&udprelayaddr, &socks5client->udprelayaddr, sizeof(udprelayaddr)) != 0) {
+    if (evutil_sockaddr_cmp((struct sockaddr *)&udprelayaddr,
+                            (struct sockaddr *)&socks5client->udprelayaddr,
+                            1) != 0) {
         char buf[RED_INET_ADDRSTRLEN];
         redudp_log_error(client, LOG_NOTICE, "Got packet from unexpected address %s.",
                          red_inet_ntop(&udprelayaddr, buf, sizeof(buf)));
@@ -211,7 +227,7 @@ static void socks5_pkt_from_socks(int fd, short what, void *_arg)
     }
     // TODO: Support domain addr
 
-    fwdlen = pktlen - sizeof(pkt->header);
+    fwdlen = pktlen - header_size;
     redudp_fwd_pkt_to_sender(client, pkt->buf + header_size, fwdlen, &src_addr);
 }
 

diff --git a/socks5.h b/socks5.h
@@ -63,7 +63,7 @@ typedef struct socks5_reply_t {
 	/* socks5_addr_* */
 } PACKED socks5_reply;
 
-typedef struct socks5_udp_preabmle_t {
+typedef struct socks5_udp_preamble_t {
 	uint16_t reserved;
 	uint8_t  frag_no;
 	uint8_t  addrtype;   /* 0x01 for IPv4 */
@@ -72,7 +72,10 @@ typedef struct socks5_udp_preabmle_t {
 	   socks5_addr_ipv4 v4;
 	   socks5_addr_ipv6 v6;
 	} addr;
-} PACKED socks5_udp_preabmle;
+} PACKED socks5_udp_preamble;
+
+#define SOCKS5_UDP_PREAMBLE_SIZE_V4 (4 + sizeof(socks5_addr_ipv4))
+#define SOCKS5_UDP_PREAMBLE_SIZE_V6 (4 + sizeof(socks5_addr_ipv6))
 
 static const int socks5_reply_maxlen = 512; // as domain name can't be longer than 256 bytes
 static const int socks5_addrtype_ipv4 = 1;