From 5e13d396eee26082c21cff20fe821da4461a6154 Mon Sep 17 00:00:00 2001
From: Max Lv <max.c.lv@gmail.com>
Date: Tue, 7 Mar 2017 12:05:07 +0800
Subject: [PATCH] Refine port binding

---
 src/local.c    | 13 ++++++++-----
 src/redir.c    | 13 ++++++++-----
 src/server.c   | 13 ++++++++-----
 src/tunnel.c   | 13 ++++++++-----
 src/udprelay.c |  7 ++++---
 5 files changed, 36 insertions(+), 23 deletions(-)

diff --git a/src/local.c b/src/local.c
index 8fbca925..0553e710 100644
--- a/src/local.c
+++ b/src/local.c
@@ -156,13 +156,20 @@ create_and_bind(const char *addr, const char *port)
     memset(&hints, 0, sizeof(struct addrinfo));
     hints.ai_family   = AF_UNSPEC;   /* Return IPv4 and IPv6 choices */
     hints.ai_socktype = SOCK_STREAM; /* We want a TCP socket */
+    result = NULL;
 
     s = getaddrinfo(addr, port, &hints, &result);
+
     if (s != 0) {
         LOGI("getaddrinfo: %s", gai_strerror(s));
         return -1;
     }
 
+    if (result == NULL) {
+        LOGE("Could not bind");
+        return -1;
+    }
+
     for (rp = result; rp != NULL; rp = rp->ai_next) {
         listen_sock = socket(rp->ai_family, rp->ai_socktype, rp->ai_protocol);
         if (listen_sock == -1) {
@@ -190,11 +197,7 @@ create_and_bind(const char *addr, const char *port)
         }
 
         close(listen_sock);
-    }
-
-    if (rp == NULL) {
-        LOGE("Could not bind");
-        return -1;
+        listen_sock = -1;
     }
 
     freeaddrinfo(result);
diff --git a/src/redir.c b/src/redir.c
index 35b29116..2a97d324 100644
--- a/src/redir.c
+++ b/src/redir.c
@@ -140,12 +140,19 @@ create_and_bind(const char *addr, const char *port)
     hints.ai_family   = AF_UNSPEC;   /* Return IPv4 and IPv6 choices */
     hints.ai_socktype = SOCK_STREAM; /* We want a TCP socket */
 
+    result = NULL;
+
     s = getaddrinfo(addr, port, &hints, &result);
     if (s != 0) {
         LOGI("getaddrinfo: %s", gai_strerror(s));
         return -1;
     }
 
+    if (result == NULL) {
+        LOGE("Could not bind");
+        return -1;
+    }
+
     for (rp = result; rp != NULL; rp = rp->ai_next) {
         listen_sock = socket(rp->ai_family, rp->ai_socktype, rp->ai_protocol);
         if (listen_sock == -1) {
@@ -173,11 +180,7 @@ create_and_bind(const char *addr, const char *port)
         }
 
         close(listen_sock);
-    }
-
-    if (rp == NULL) {
-        LOGE("Could not bind");
-        return -1;
+        listen_sock = -1;
     }
 
     freeaddrinfo(result);
diff --git a/src/server.c b/src/server.c
index 59659a84..23c5bb9d 100644
--- a/src/server.c
+++ b/src/server.c
@@ -328,6 +328,8 @@ create_and_bind(const char *host, const char *port, int mptcp)
     hints.ai_flags    = AI_PASSIVE | AI_ADDRCONFIG; /* For wildcard IP address */
     hints.ai_protocol = IPPROTO_TCP;
 
+    result = NULL;
+
     for (int i = 1; i < 8; i++) {
         s = getaddrinfo(host, port, &hints, &result);
         if (s == 0) {
@@ -343,6 +345,11 @@ create_and_bind(const char *host, const char *port, int mptcp)
         return -1;
     }
 
+    if (result == NULL) {
+        LOGE("Could not bind");
+        return -1;
+    }
+
     rp = result;
 
     /*
@@ -410,11 +417,7 @@ create_and_bind(const char *host, const char *port, int mptcp)
         }
 
         close(listen_sock);
-    }
-
-    if (rp == NULL) {
-        LOGE("Could not bind");
-        return -1;
+        listen_sock = -1;
     }
 
     freeaddrinfo(result);
diff --git a/src/tunnel.c b/src/tunnel.c
index 9c792f84..40d8047b 100644
--- a/src/tunnel.c
+++ b/src/tunnel.c
@@ -121,12 +121,19 @@ create_and_bind(const char *addr, const char *port)
     hints.ai_family   = AF_UNSPEC;   /* Return IPv4 and IPv6 choices */
     hints.ai_socktype = SOCK_STREAM; /* We want a TCP socket */
 
+    result = NULL;
+
     s = getaddrinfo(addr, port, &hints, &result);
     if (s != 0) {
         LOGI("getaddrinfo: %s", gai_strerror(s));
         return -1;
     }
 
+    if (result == NULL) {
+        LOGE("Could not bind");
+        return -1;
+    }
+
     for (rp = result; rp != NULL; rp = rp->ai_next) {
         listen_sock = socket(rp->ai_family, rp->ai_socktype, rp->ai_protocol);
         if (listen_sock == -1) {
@@ -154,11 +161,7 @@ create_and_bind(const char *addr, const char *port)
         }
 
         close(listen_sock);
-    }
-
-    if (rp == NULL) {
-        LOGE("Could not bind");
-        return -1;
+        listen_sock = -1;
     }
 
     freeaddrinfo(result);
diff --git a/src/udprelay.c b/src/udprelay.c
index 781fbc14..3c26eda4 100644
--- a/src/udprelay.c
+++ b/src/udprelay.c
@@ -389,13 +389,13 @@ create_server_socket(const char *host, const char *port)
         return -1;
     }
 
-    rp = result;
-
-    if (rp == NULL) {
+    if (result == NULL) {
         LOGE("[udp] cannot bind");
         return -1;
     }
 
+    rp = result;
+
     /*
      * On Linux, with net.ipv6.bindv6only = 0 (the default), getaddrinfo(NULL) with
      * AI_PASSIVE returns 0.0.0.0 and :: (in this order). AI_PASSIVE was meant to
@@ -462,6 +462,7 @@ create_server_socket(const char *host, const char *port)
         }
 
         close(server_sock);
+        server_sock = -1;
     }
 
     freeaddrinfo(result);