fixed a bug in domain name validation

src/CMakeLists.txt

@@ -34,7 +34,7 @@ set(SS_SHARED_SOURCES
         json.c
         cache.c
         netutils.c
-        relay.c
+        tcprelay.c
         )
 
 set(LIBSHADOWSOCKS_LIBEV_SOURCE

src/Makefile.am

@@ -42,7 +42,7 @@ common_src = utils.c \
              jconf.c \
              json.c \
              udprelay.c \
-             relay.c \
+             tcprelay.c \
              cache.c \
              netutils.c
 
@@ -101,7 +101,7 @@ ss_redir_SOURCES = utils.c \
                    netutils.c \
                    cache.c \
                    udprelay.c \
-                   relay.c \
+                   tcprelay.c \
                    redir.c \
                    $(crypto_src) \
                    $(plugin_src) \
@@ -122,5 +122,5 @@ include_HEADERS = shadowsocks.h
 
 noinst_HEADERS = acl.h crypto.h stream.h aead.h json.h netutils.h tls.h uthash.h \
                  cache.h http.h plugin.h resolv.h utils.h base64.h ppbloom.h \
-                 common.h jconf.h manager.h protocol.h rule.h socks5.h udprelay.h relay.h winsock.h
+                 common.h jconf.h manager.h protocol.h rule.h socks5.h udprelay.h tcprelay.h winsock.h
 EXTRA_DIST = ss-nat

src/local.c

@@ -57,7 +57,7 @@
 #include "tls.h"
 #include "plugin.h"
 #include "winsock.h"
-#include "relay.h"
+#include "tcprelay.h"
 #include "acl.h"
 
 #ifndef LIB_ONLY

src/netutils.c

@@ -601,48 +601,13 @@ sockaddr_cmp_addr(struct sockaddr_storage *addr1,
     }
 }
 
-int
-validate_hostname(const char *hostname, const int hostname_len)
-{
-    if (hostname == NULL)
-        return 0;
-
-    if (hostname_len < 1 || hostname_len > 255)
-        return 0;
-
-    if (hostname[0] == '.')
-        return 0;
-
-    const char *label = hostname;
-    while (label < hostname + hostname_len) {
-        size_t label_len = hostname_len - (label - hostname);
-        char *next_dot   = strchr(label, '.');
-        if (next_dot != NULL)
-            label_len = next_dot - label;
-
-        if (label + label_len > hostname + hostname_len)
-            return 0;
-
-        if (label_len > 63 || label_len < 1)
-            return 0;
-
-        if (label[0] == '-' || label[label_len - 1] == '-')
-            return 0;
-
-        if (strspn(label, valid_label_bytes) < label_len)
-            return 0;
-
-        label += label_len + 1;
-    }
-
-    return 1;
-}
-
 char *
-hostname_readable(char *dname, uint16_t port)
+hostname_readable(const char *dname,
+                  const int dname_len, uint16_t port)
 {
-    char *ret = ss_calloc(strlen(dname) + MAX_PORT_STR_LEN, sizeof(*ret));
-    sprintf(ret, "%s:%d", dname, ntohs(port));
+    size_t len = dname_len + MAX_PORT_STR_LEN;
+    char *ret = ss_calloc(len , sizeof(*ret));
+    snprintf(ret, len, "%.*s:%d", dname_len, dname, ntohs(port));
     return ret;
 }
 

src/netutils.h

@@ -263,8 +263,7 @@ int sockaddr_cmp(struct sockaddr_storage *addr1,
 int sockaddr_cmp_addr(struct sockaddr_storage *addr1,
                       struct sockaddr_storage *addr2, socklen_t len);
 
-int validate_hostname(const char *hostname, const int hostname_len);
-char *hostname_readable(char *dname, uint16_t port);
+char *hostname_readable(const char *dname, const int dname_len, uint16_t port);
 
 int is_addr_loopback(const struct sockaddr *addr);
 

src/redir.c

@@ -49,7 +49,7 @@
 #include "utils.h"
 #include "common.h"
 #include "acl.h"
-#include "relay.h"
+#include "tcprelay.h"
 
 int verbose    = 0;
 int ipv6first  = 0;

src/server.c

@@ -55,7 +55,7 @@
 #include "acl.h"
 #include "plugin.h"
 #include "winsock.h"
-#include "relay.h"
+#include "tcprelay.h"
 
 #ifndef SSMAXCONN
 #define SSMAXCONN 1024

src/shadowsocks.h

@@ -123,6 +123,8 @@ void free_ssocks_addr(ssocks_addr_t *destaddr)
  * parse_ssocks_header
  * create_ssocks_header
  *
+ * CAVEATS: The domain name is not null-terminated
+ *
  * / Pre-encryption //////////////////////
  * - Shadowsocks Request
  *   +------+----------+----------+----------+
@@ -182,32 +184,9 @@ parse_ssocks_header(buffer_t *buf, ssocks_addr_t *destaddr, int offset)
             memcpy(dname, buf->data + offset + 1, dname_len);
             offset += dname_len + 1;
 
+            destaddr->dname = dname;
+            destaddr->dname_len = dname_len;
             destaddr->port = *(uint16_t *)(buf->data + offset);
-
-            struct cork_ip ip;
-            if (cork_ip_init(&ip, dname) != -1) {
-                switch (ip.version) {
-                    case 4: {
-                        struct sockaddr_in *addr
-                                         = ss_calloc(1, sizeof(*addr));
-                        addr->sin_family = AF_INET;
-                        memcpy(&addr->sin_addr, &ip.ip.v4, sizeof(ip.ip.v4));
-                        addr->sin_port   = destaddr->port;
-                        destaddr->addr   = (struct sockaddr_storage *)addr;
-                    } break;
-                    case 6: {
-                        struct sockaddr_in6 *addr
-                                          = ss_calloc(1, sizeof(*addr));
-                        addr->sin6_family = AF_INET;
-                        memcpy(&addr->sin6_addr, &ip.ip.v6, sizeof(ip.ip.v6));
-                        addr->sin6_port   = destaddr->port;
-                        destaddr->addr    = (struct sockaddr_storage *)addr;
-                    } break;
-                }
-            } else {
-                destaddr->dname = dname;
-                destaddr->dname_len = dname_len;
-            }
         } break;
         case SSOCKS_ATYP_IPV6: {
             size_t in6_addr_len = sizeof(struct in_addr);

src/relay.c → src/tcprelay.c

@@ -57,7 +57,7 @@
 #include "acl.h"
 #include "plugin.h"
 
-#include "relay.h"
+#include "tcprelay.h"
 
 extern int acl;
 extern int verbose;
@@ -183,7 +183,7 @@ create_remote(EV_P_ remote_t *remote, buffer_t *buf,
     if (destaddr->dname_len == -1) {
         return -1;
     } else if (destaddr->dname_len <= 0 ||
-               !validate_hostname(destaddr->dname, destaddr->dname_len))
+               destaddr->dname_len >= MAX_HOSTNAME_LEN)
     {
         destaddr->dname = NULL;
     }
@@ -197,7 +197,7 @@ create_remote(EV_P_ remote_t *remote, buffer_t *buf,
 
     if (verbose) {
         LOGI("%s %s", direct ? "bypassing" : "connecting to",
-             destaddr->dname ? hostname_readable(destaddr->dname, destaddr->port)
+             destaddr->dname ? hostname_readable(destaddr->dname, destaddr->dname_len, destaddr->port)
                              : sockaddr_readable("%a:%p", destaddr->addr));
     }
 

src/relay.h → src/tcprelay.h

@@ -20,8 +20,8 @@
  * <http://www.gnu.org/licenses/>.
  */
 
-#ifndef _RELAY_H
-#define _RELAY_H
+#ifndef _TCP_RELAY_H
+#define _TCP_RELAY_H
 
 #include <time.h>
 

src/tunnel.c

@@ -54,7 +54,7 @@
 #include "utils.h"
 #include "plugin.h"
 #include "winsock.h"
-#include "relay.h"
+#include "tcprelay.h"
 
 int verbose = 0;
 int acl = 0;

src/udprelay.c

@@ -691,7 +691,7 @@ server_recv_cb(EV_P_ ev_io *w, int revents)
     }
 
     if (destaddr->dname_len <= 0 ||
-        !validate_hostname(destaddr->dname, destaddr->dname_len))
+        destaddr->dname_len >= MAX_HOSTNAME_LEN)
     {
         destaddr->dname = NULL;
     }
@@ -705,7 +705,7 @@ server_recv_cb(EV_P_ ev_io *w, int revents)
 
     if (verbose) {
         LOGI("%s %s", remote->direct ? "bypassing" : "connecting to",
-             destaddr->dname ? hostname_readable(destaddr->dname, destaddr->port)
+             destaddr->dname ? hostname_readable(destaddr->dname, destaddr->dname_len, destaddr->port)
                              : sockaddr_readable("%a:%p", destaddr->addr));
     }