From: Daniel Stenberg <daniel@haxx.se>
Date: Wed, 21 Aug 2024 09:07:06 +0000 (+0200)
Subject: setopt: allow CURLOPT_INTERFACE to be set to NULL
X-Git-Tag: curl-8_10_0~169
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=b0b4b481b5b6e210a416ebbe16c2b8a77678e85d;p=thirdparty%2Fcurl.git

setopt: allow CURLOPT_INTERFACE to be set to NULL

Ref: https://github.com/curl/curl/discussions/14299#discussioncomment-10393909
Regression from 3060557af702dd591 (shipped in 8.9.0)

Closes #14629
---

diff --git a/lib/cf-socket.c b/lib/cf-socket.c
index 3f0fb32bf8..c1f1ac866e 100644
--- a/lib/cf-socket.c
+++ b/lib/cf-socket.c
@@ -511,32 +511,37 @@ void Curl_sndbuf_init(curl_socket_t sockfd)
  *
  * Returns CURLE_OK on success.
  */
-CURLcode Curl_parse_interface(const char *input, size_t len,
+CURLcode Curl_parse_interface(const char *input,
                               char **dev, char **iface, char **host)
 {
   static const char if_prefix[] = "if!";
   static const char host_prefix[] = "host!";
   static const char if_host_prefix[] = "ifhost!";
+  size_t len;
 
   DEBUGASSERT(dev);
   DEBUGASSERT(iface);
   DEBUGASSERT(host);
 
-  if(strncmp(if_prefix, input, strlen(if_prefix)) == 0) {
+  len = strlen(input);
+  if(len > 512)
+    return CURLE_BAD_FUNCTION_ARGUMENT;
+
+  if(!strncmp(if_prefix, input, strlen(if_prefix))) {
     input += strlen(if_prefix);
     if(!*input)
       return CURLE_BAD_FUNCTION_ARGUMENT;
     *iface = Curl_memdup0(input, len - strlen(if_prefix));
     return *iface ? CURLE_OK : CURLE_OUT_OF_MEMORY;
   }
-  if(strncmp(host_prefix, input, strlen(host_prefix)) == 0) {
+  else if(!strncmp(host_prefix, input, strlen(host_prefix))) {
     input += strlen(host_prefix);
     if(!*input)
       return CURLE_BAD_FUNCTION_ARGUMENT;
     *host = Curl_memdup0(input, len - strlen(host_prefix));
     return *host ? CURLE_OK : CURLE_OUT_OF_MEMORY;
   }
-  if(strncmp(if_host_prefix, input, strlen(if_host_prefix)) == 0) {
+  else if(!strncmp(if_host_prefix, input, strlen(if_host_prefix))) {
     const char *host_part;
     input += strlen(if_host_prefix);
     len -= strlen(if_host_prefix);
diff --git a/lib/cf-socket.h b/lib/cf-socket.h
index 6040058b09..35225f153c 100644
--- a/lib/cf-socket.h
+++ b/lib/cf-socket.h
@@ -57,7 +57,7 @@ struct Curl_sockaddr_ex {
 /*
  * Parse interface option, and return the interface name and the host part.
 */
-CURLcode Curl_parse_interface(const char *input, size_t len,
+CURLcode Curl_parse_interface(const char *input,
                               char **dev, char **iface, char **host);
 
 /*
diff --git a/lib/setopt.c b/lib/setopt.c
index 538bd52ad8..9d695e09d3 100644
--- a/lib/setopt.c
+++ b/lib/setopt.c
@@ -139,30 +139,24 @@ static CURLcode setstropt_userpwd(char *option, char **userp, char **passwdp)
   return CURLE_OK;
 }
 
-static CURLcode setstropt_interface(
-  char *option, char **devp, char **ifacep, char **hostp)
+static CURLcode setstropt_interface(char *option, char **devp,
+                                    char **ifacep, char **hostp)
 {
   char *dev = NULL;
   char *iface = NULL;
   char *host = NULL;
-  size_t len;
   CURLcode result;
 
   DEBUGASSERT(devp);
   DEBUGASSERT(ifacep);
   DEBUGASSERT(hostp);
 
-  /* Parse the interface details */
-  if(!option || !*option)
-    return CURLE_BAD_FUNCTION_ARGUMENT;
-  len = strlen(option);
-  if(len > 255)
-    return CURLE_BAD_FUNCTION_ARGUMENT;
-
-  result = Curl_parse_interface(option, len, &dev, &iface, &host);
-  if(result)
-    return result;
-
+  if(option) {
+    /* Parse the interface details if set, otherwise clear them all */
+    result = Curl_parse_interface(option, &dev, &iface, &host);
+    if(result)
+      return result;
+  }
   free(*devp);
   *devp = dev;
 
diff --git a/tests/unit/unit1663.c b/tests/unit/unit1663.c
index f4801fe5cc..e7fe621666 100644
--- a/tests/unit/unit1663.c
+++ b/tests/unit/unit1663.c
@@ -58,8 +58,7 @@ static void test_parse(
   char *dev = NULL;
   char *iface = NULL;
   char *host = NULL;
-  CURLcode rc = Curl_parse_interface(
-    input, strlen(input), &dev, &iface, &host);
+  CURLcode rc = Curl_parse_interface(input, &dev, &iface, &host);
   fail_unless(rc == exp_rc, "Curl_parse_interface() failed");
 
   fail_unless(!!exp_dev == !!dev, "dev expectation failed.");