From: Viktor Szakats <commit@vsz.me>
Date: Tue, 9 Sep 2025 13:29:12 +0000 (+0200)
Subject: build: avoid overriding system symbols for socket functions
X-Git-Tag: rc-8_17_0-1~322
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=bf7375ecc50e857760b0d0a668c436e208a400bd;p=thirdparty%2Fcurl.git

build: avoid overriding system symbols for socket functions

Before this patch `accept4()`, `socket()`, `socketpair()`, `send()` and
`recv()` system symbols were remapped via macros, using the same name,
to local curl debug wrappers. This patch replaces these overrides by
introducing curl-namespaced macros that map either to the system symbols
or to their curl debug wrappers in `CURLDEBUG` (TrackMemory) builds.

This follows a patch that implemented the same for `accept()`.

The old method required tricks to make these redefines work in unity
builds, and avoid them interfering with system headers. These tricks
did not work for system symbols implemented as macros.

The new method allows to setup these mappings once, without interfering
with system headers, upstream macros, or unity builds. It makes builds
more robust.

Also:
- checksrc: ban all mapped functions.
- docs/examples: tidy up checksrc rules.

Follow-up to 9863599d69b79d290928a89bf9160f4e4e023d4e #18502
Follow-up to 3bb5e58c105d7be450b667858d1b8e7ae3ded555 #17827

Closes #18503
---

diff --git a/REUSE.toml b/REUSE.toml
index 81c214863f..6e8a272e79 100644
--- a/REUSE.toml
+++ b/REUSE.toml
@@ -40,6 +40,7 @@ path = [
   "tests/data/test**",
   "tests/valgrind.supp",
   # checksrc control files
+  "docs/examples/.checksrc",
   "lib/.checksrc",
   "lib/curlx/.checksrc",
   "lib/vauth/.checksrc",
diff --git a/docs/examples/.checksrc b/docs/examples/.checksrc
new file mode 100644
index 0000000000..0b626e6570
--- /dev/null
+++ b/docs/examples/.checksrc
@@ -0,0 +1,3 @@
+allowfunc gmtime
+allowfunc localtime
+allowfunc socket
diff --git a/docs/examples/Makefile.am b/docs/examples/Makefile.am
index 27d4ce741b..89ebcc9840 100644
--- a/docs/examples/Makefile.am
+++ b/docs/examples/Makefile.am
@@ -24,7 +24,7 @@
 
 AUTOMAKE_OPTIONS = foreign nostdinc
 
-EXTRA_DIST = CMakeLists.txt README.md Makefile.example $(COMPLICATED_EXAMPLES)
+EXTRA_DIST = CMakeLists.txt .checksrc README.md Makefile.example $(COMPLICATED_EXAMPLES)
 
 # Specify our include paths here, and do it relative to $(top_srcdir) and
 # $(top_builddir), to ensure that these paths which belong to the library
diff --git a/docs/examples/http2-upload.c b/docs/examples/http2-upload.c
index 128a4b0bed..d13c5e5806 100644
--- a/docs/examples/http2-upload.c
+++ b/docs/examples/http2-upload.c
@@ -161,7 +161,6 @@ int my_trace(CURL *handle, curl_infotype type,
     known_offset = 1;
   }
   secs = epoch_offset + tv.tv_sec;
-  /* !checksrc! disable BANNEDFUNC 1 */
   now = localtime(&secs);  /* not thread safe but we do not care */
   curl_msnprintf(timebuf, sizeof(timebuf), "%02d:%02d:%02d.%06ld",
                  now->tm_hour, now->tm_min, now->tm_sec, (long)tv.tv_usec);
diff --git a/docs/examples/synctime.c b/docs/examples/synctime.c
index ba5f09cb07..8d7af7c8c4 100644
--- a/docs/examples/synctime.c
+++ b/docs/examples/synctime.c
@@ -298,10 +298,8 @@ int main(int argc, char *argv[])
 
     /* Calculating time diff between GMT and localtime */
     tt       = time(0);
-    /* !checksrc! disable BANNEDFUNC 1 */
     lt       = localtime(&tt);
     tt_local = mktime(lt);
-    /* !checksrc! disable BANNEDFUNC 1 */
     gmt      = gmtime(&tt);
     tt_gmt   = mktime(gmt);
     tzonediffFloat = difftime(tt_local, tt_gmt);
diff --git a/lib/cf-socket.c b/lib/cf-socket.c
index d7463345ad..365ddb62a1 100644
--- a/lib/cf-socket.c
+++ b/lib/cf-socket.c
@@ -369,7 +369,7 @@ static CURLcode socket_open(struct Curl_easy *data,
   }
   else {
     /* opensocket callback not set, so simply create the socket now */
-    *sockfd = socket(addr->family, addr->socktype, addr->protocol);
+    *sockfd = CURL_SOCKET(addr->family, addr->socktype, addr->protocol);
   }
 
   if(*sockfd == CURL_SOCKET_BAD)
@@ -2113,8 +2113,8 @@ static CURLcode cf_tcp_accept_connect(struct Curl_cfilter *cf,
   if(!getsockname(ctx->sock, (struct sockaddr *) &add, &size)) {
     size = sizeof(add);
 #ifdef HAVE_ACCEPT4
-    s_accepted = accept4(ctx->sock, (struct sockaddr *) &add, &size,
-                         SOCK_NONBLOCK | SOCK_CLOEXEC);
+    s_accepted = CURL_ACCEPT4(ctx->sock, (struct sockaddr *) &add, &size,
+                              SOCK_NONBLOCK | SOCK_CLOEXEC);
 #else
     s_accepted = CURL_ACCEPT(ctx->sock, (struct sockaddr *) &add, &size);
 #endif
diff --git a/lib/curl_addrinfo.c b/lib/curl_addrinfo.c
index 22212ac86f..c4ad71a02e 100644
--- a/lib/curl_addrinfo.c
+++ b/lib/curl_addrinfo.c
@@ -507,9 +507,11 @@ curl_dbg_freeaddrinfo(struct addrinfo *freethis,
     if(env)
       r_freeaddrinfo(freethis);
     else
+      /* !checksrc! disable BANNEDFUNC 1 */
       freeaddrinfo(freethis);
   }
 #else
+  /* !checksrc! disable BANNEDFUNC 1 */
   freeaddrinfo(freethis);
 #endif
 }
@@ -540,8 +542,10 @@ curl_dbg_getaddrinfo(const char *hostname,
   if(env)
     res = r_getaddrinfo(hostname, service, hints, result);
   else
+    /* !checksrc! disable BANNEDFUNC 1 */
     res = getaddrinfo(hostname, service, hints, result);
 #else
+  /* !checksrc! disable BANNEDFUNC 1 */
   int res = getaddrinfo(hostname, service, hints, result);
 #endif
   if(res == 0)
diff --git a/lib/curl_mem_undef.h b/lib/curl_mem_undef.h
index f3cca294e9..a70a9fcf53 100644
--- a/lib/curl_mem_undef.h
+++ b/lib/curl_mem_undef.h
@@ -35,17 +35,6 @@
 
 #ifdef CURLDEBUG
 
-#undef send
-#undef recv
-
-#undef socket
-#ifdef HAVE_ACCEPT4
-#undef accept4
-#endif
-#ifdef HAVE_SOCKETPAIR
-#undef socketpair
-#endif
-
 #undef fopen
 #ifdef CURL_FOPEN
 #define fopen(fname, mode) CURL_FOPEN(fname, mode)
diff --git a/lib/curl_setup.h b/lib/curl_setup.h
index 93cbb57056..e49c57231d 100644
--- a/lib/curl_setup.h
+++ b/lib/curl_setup.h
@@ -1083,9 +1083,21 @@ CURL_EXTERN ALLOC_FUNC
   curl_dbg_getaddrinfo(host, serv, hint, res, __LINE__, __FILE__)
 #define CURL_FREEADDRINFO(data) \
   curl_dbg_freeaddrinfo(data, __LINE__, __FILE__)
-
+#define CURL_SOCKET(domain,type,protocol) \
+  curl_dbg_socket((int)domain, type, protocol, __LINE__, __FILE__)
+#ifdef HAVE_SOCKETPAIR
+#define CURL_SOCKETPAIR(domain,type,protocol,socket_vector) \
+  curl_dbg_socketpair((int)domain, type, protocol, socket_vector, \
+                      __LINE__, __FILE__)
+#endif
 #define CURL_ACCEPT(sock,addr,len) \
   curl_dbg_accept(sock, addr, len, __LINE__, __FILE__)
+#ifdef HAVE_ACCEPT4
+#define CURL_ACCEPT4(sock,addr,len,flags) \
+  curl_dbg_accept4(sock, addr, len, flags, __LINE__, __FILE__)
+#endif
+#define CURL_SEND(a,b,c,d) curl_dbg_send(a,b,c,d, __LINE__, __FILE__)
+#define CURL_RECV(a,b,c,d) curl_dbg_recv(a,b,c,d, __LINE__, __FILE__)
 
 #else /* !CURLDEBUG */
 
@@ -1094,8 +1106,16 @@ CURL_EXTERN ALLOC_FUNC
 
 #define CURL_GETADDRINFO getaddrinfo
 #define CURL_FREEADDRINFO freeaddrinfo
-
+#define CURL_SOCKET socket
+#ifdef HAVE_SOCKETPAIR
+#define CURL_SOCKETPAIR socketpair
+#endif
 #define CURL_ACCEPT accept
+#ifdef HAVE_ACCEPT4
+#define CURL_ACCEPT4 accept4
+#endif
+#define CURL_SEND send
+#define CURL_RECV recv
 
 #endif /* CURLDEBUG */
 
diff --git a/lib/hostip.c b/lib/hostip.c
index b6be2ca1f2..fd8f706e7f 100644
--- a/lib/hostip.c
+++ b/lib/hostip.c
@@ -709,7 +709,7 @@ bool Curl_ipv6works(struct Curl_easy *data)
   else {
     int ipv6_works = -1;
     /* probe to see if we have a working IPv6 stack */
-    curl_socket_t s = socket(PF_INET6, SOCK_DGRAM, 0);
+    curl_socket_t s = CURL_SOCKET(PF_INET6, SOCK_DGRAM, 0);
     if(s == CURL_SOCKET_BAD)
       /* an IPv6 address was requested but we cannot get/use one */
       ipv6_works = 0;
diff --git a/lib/if2ip.c b/lib/if2ip.c
index 91ee59c02a..e501921d06 100644
--- a/lib/if2ip.c
+++ b/lib/if2ip.c
@@ -208,7 +208,7 @@ if2ip_result_t Curl_if2ip(int af,
   if(len >= sizeof(req.ifr_name))
     return IF2IP_NOT_FOUND;
 
-  dummy = socket(AF_INET, SOCK_STREAM, 0);
+  dummy = CURL_SOCKET(AF_INET, SOCK_STREAM, 0);
   if(CURL_SOCKET_BAD == dummy)
     return IF2IP_NOT_FOUND;
 
diff --git a/lib/memdebug.c b/lib/memdebug.c
index 0d8d39603c..cffd4b2cf6 100644
--- a/lib/memdebug.c
+++ b/lib/memdebug.c
@@ -311,7 +311,8 @@ curl_socket_t curl_dbg_socket(int domain, int type, int protocol,
   if(countcheck("socket", line, source))
     return CURL_SOCKET_BAD;
 
-  sockfd = (socket)(domain, type, protocol);
+  /* !checksrc! disable BANNEDFUNC 1 */
+  sockfd = socket(domain, type, protocol);
 
   if(source && (sockfd != CURL_SOCKET_BAD))
     curl_dbg_log("FD %s:%d socket() = %" FMT_SOCKET_T "\n",
@@ -328,7 +329,8 @@ SEND_TYPE_RETV curl_dbg_send(SEND_TYPE_ARG1 sockfd,
   SEND_TYPE_RETV rc;
   if(countcheck("send", line, source))
     return -1;
-  rc = (send)(sockfd, buf, len, flags);
+  /* !checksrc! disable BANNEDFUNC 1 */
+  rc = send(sockfd, buf, len, flags);
   if(source)
     curl_dbg_log("SEND %s:%d send(%lu) = %ld\n",
                 source, line, (unsigned long)len, (long)rc);
@@ -342,7 +344,8 @@ RECV_TYPE_RETV curl_dbg_recv(RECV_TYPE_ARG1 sockfd, RECV_TYPE_ARG2 buf,
   RECV_TYPE_RETV rc;
   if(countcheck("recv", line, source))
     return -1;
-  rc = (recv)(sockfd, buf, len, flags);
+  /* !checksrc! disable BANNEDFUNC 1 */
+  rc = recv(sockfd, buf, len, flags);
   if(source)
     curl_dbg_log("RECV %s:%d recv(%lu) = %ld\n",
                 source, line, (unsigned long)len, (long)rc);
@@ -354,7 +357,8 @@ int curl_dbg_socketpair(int domain, int type, int protocol,
                         curl_socket_t socket_vector[2],
                         int line, const char *source)
 {
-  int res = (socketpair)(domain, type, protocol, socket_vector);
+  /* !checksrc! disable BANNEDFUNC 1 */
+  int res = socketpair(domain, type, protocol, socket_vector);
 
   if(source && (res == 0))
     curl_dbg_log("FD %s:%d socketpair() = "
@@ -371,6 +375,7 @@ curl_socket_t curl_dbg_accept(curl_socket_t s, void *saddr, void *saddrlen,
   struct sockaddr *addr = (struct sockaddr *)saddr;
   curl_socklen_t *addrlen = (curl_socklen_t *)saddrlen;
 
+  /* !checksrc! disable BANNEDFUNC 1 */
   curl_socket_t sockfd = accept(s, addr, addrlen);
 
   if(source && (sockfd != CURL_SOCKET_BAD))
@@ -388,7 +393,8 @@ curl_socket_t curl_dbg_accept4(curl_socket_t s, void *saddr, void *saddrlen,
   struct sockaddr *addr = (struct sockaddr *)saddr;
   curl_socklen_t *addrlen = (curl_socklen_t *)saddrlen;
 
-  curl_socket_t sockfd = (accept4)(s, addr, addrlen, flags);
+  /* !checksrc! disable BANNEDFUNC 1 */
+  curl_socket_t sockfd = accept4(s, addr, addrlen, flags);
 
   if(source && (sockfd != CURL_SOCKET_BAD))
     curl_dbg_log("FD %s:%d accept() = %" FMT_SOCKET_T "\n",
diff --git a/lib/memdebug.h b/lib/memdebug.h
index eabdd9c258..96ceb61759 100644
--- a/lib/memdebug.h
+++ b/lib/memdebug.h
@@ -42,10 +42,6 @@
 #define realloc(ptr,size) curl_dbg_realloc(ptr, size, __LINE__, __FILE__)
 #undef free
 #define free(ptr) curl_dbg_free(ptr, __LINE__, __FILE__)
-#undef send
-#define send(a,b,c,d) curl_dbg_send(a,b,c,d, __LINE__, __FILE__)
-#undef recv
-#define recv(a,b,c,d) curl_dbg_recv(a,b,c,d, __LINE__, __FILE__)
 
 #ifdef _WIN32
 #undef Curl_tcsdup
@@ -56,20 +52,6 @@
 #endif
 #endif /* _WIN32 */
 
-#undef socket
-#define socket(domain,type,protocol) \
-  curl_dbg_socket((int)domain, type, protocol, __LINE__, __FILE__)
-#ifdef HAVE_ACCEPT4
-#undef accept4 /* for those with accept4 as a macro */
-#define accept4(sock,addr,len,flags) \
-  curl_dbg_accept4(sock, addr, len, flags, __LINE__, __FILE__)
-#endif
-#ifdef HAVE_SOCKETPAIR
-#define socketpair(domain,type,protocol,socket_vector) \
-  curl_dbg_socketpair((int)domain, type, protocol, socket_vector, \
-                      __LINE__, __FILE__)
-#endif
-
 #undef fopen
 #define fopen(file,mode) curl_dbg_fopen(file,mode,__LINE__,__FILE__)
 #undef fdopen
diff --git a/lib/multi.c b/lib/multi.c
index 918928d03c..442956f844 100644
--- a/lib/multi.c
+++ b/lib/multi.c
@@ -1277,7 +1277,7 @@ static void reset_socket_fdwrite(curl_socket_t s)
   int t;
   int l = (int)sizeof(t);
   if(!getsockopt(s, SOL_SOCKET, SO_TYPE, (char *)&t, &l) && t == SOCK_STREAM)
-    send(s, NULL, 0, 0);
+    CURL_SEND(s, NULL, 0, 0);
 }
 #endif
 
diff --git a/lib/socketpair.c b/lib/socketpair.c
index 4151a9bb97..d2fd41141b 100644
--- a/lib/socketpair.c
+++ b/lib/socketpair.c
@@ -91,7 +91,7 @@ int Curl_socketpair(int domain, int type, int protocol,
 #ifdef SOCK_NONBLOCK
   type = nonblocking ? type | SOCK_NONBLOCK : type;
 #endif
-  if(socketpair(domain, type, protocol, socks))
+  if(CURL_SOCKETPAIR(domain, type, protocol, socks))
     return -1;
 #ifndef SOCK_NONBLOCK
   if(nonblocking) {
@@ -154,7 +154,7 @@ int Curl_socketpair(int domain, int type, int protocol,
   (void)type;
   (void)protocol;
 
-  listener = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
+  listener = CURL_SOCKET(AF_INET, SOCK_STREAM, IPPROTO_TCP);
   if(listener == CURL_SOCKET_BAD)
     return -1;
 
@@ -188,7 +188,7 @@ int Curl_socketpair(int domain, int type, int protocol,
     goto error;
   if(listen(listener, 1) == -1)
     goto error;
-  socks[0] = socket(AF_INET, SOCK_STREAM, 0);
+  socks[0] = CURL_SOCKET(AF_INET, SOCK_STREAM, 0);
   if(socks[0] == CURL_SOCKET_BAD)
     goto error;
   if(connect(socks[0], &a.addr, sizeof(a.inaddr)) == -1)
diff --git a/lib/vquic/vquic.c b/lib/vquic/vquic.c
index 3a0ac87238..47fbf63af0 100644
--- a/lib/vquic/vquic.c
+++ b/lib/vquic/vquic.c
@@ -196,8 +196,8 @@ static CURLcode do_sendmsg(struct Curl_cfilter *cf,
 
   *psent = 0;
 
-  while((sent = send(qctx->sockfd,
-                     (const char *)pkt, (SEND_TYPE_ARG3)pktlen, 0)) == -1 &&
+  while((sent = CURL_SEND(qctx->sockfd, (const char *)pkt,
+                          (SEND_TYPE_ARG3)pktlen, 0)) == -1 &&
         SOCKERRNO == SOCKEINTR)
     ;
 
diff --git a/packages/OS400/os400sys.c b/packages/OS400/os400sys.c
index 7be7208549..bc227a0e69 100644
--- a/packages/OS400/os400sys.c
+++ b/packages/OS400/os400sys.c
@@ -333,6 +333,7 @@ Curl_getaddrinfo_a(const char *nodename, const char *servname,
     eservname[i] = '\0';
   }
 
+  /* !checksrc! disable BANNEDFUNC 1 */
   status = getaddrinfo(enodename, eservname, hints, res);
   free(enodename);
   free(eservname);
diff --git a/scripts/checksrc.pl b/scripts/checksrc.pl
index 28ad6315ba..0eeab72323 100755
--- a/scripts/checksrc.pl
+++ b/scripts/checksrc.pl
@@ -77,6 +77,14 @@ my %banfunc = (
     "_waccess" => 1,
     "_access" => 1,
     "access" => 1,
+    "accept" => 1,
+    "accept4" => 1,
+    "freeaddrinfo" => 1,
+    "getaddrinfo" => 1,
+    "recv" => 1,
+    "send" => 1,
+    "socket" => 1,
+    "socketpair" => 1,
     );
 
 my %warnings_extended = (
diff --git a/src/tool_cb_rea.c b/src/tool_cb_rea.c
index 0a3e9ef0ee..b7bd9a7227 100644
--- a/src/tool_cb_rea.c
+++ b/src/tool_cb_rea.c
@@ -92,7 +92,7 @@ size_t tool_read_cb(char *buffer, size_t sz, size_t nmemb, void *userdata)
    execute */
   if(per->uploadfile && !strcmp(per->uploadfile, ".") && per->infd > 0) {
 #if defined(_WIN32) && !defined(CURL_WINDOWS_UWP) && !defined(UNDER_CE)
-    rc = recv(per->infd, buffer, curlx_uztosi(sz * nmemb), 0);
+    rc = CURL_RECV(per->infd, buffer, curlx_uztosi(sz * nmemb), 0);
     if(rc < 0) {
       if(SOCKERRNO == SOCKEWOULDBLOCK) {
         CURL_SETERRNO(0);
diff --git a/src/tool_cb_soc.c b/src/tool_cb_soc.c
index 22048ee6bb..d89870297c 100644
--- a/src/tool_cb_soc.c
+++ b/src/tool_cb_soc.c
@@ -54,5 +54,5 @@ curl_socket_t tool_socket_open_mptcp_cb(void *clientp,
     return CURL_SOCKET_BAD;
 #endif
 
-  return socket(addr->family, addr->socktype, protocol);
+  return CURL_SOCKET(addr->family, addr->socktype, protocol);
 }
diff --git a/src/tool_doswin.c b/src/tool_doswin.c
index bfe013d8e5..0450e5707b 100644
--- a/src/tool_doswin.c
+++ b/src/tool_doswin.c
@@ -785,7 +785,7 @@ static DWORD WINAPI win_stdin_thread_func(void *thread_data)
       break;
     if(n == 0)
       break;
-    nwritten = send(socket_w, buffer, n, 0);
+    nwritten = CURL_SEND(socket_w, buffer, n, 0);
     if(nwritten == SOCKET_ERROR)
       break;
     if((DWORD)nwritten != n)
@@ -889,7 +889,7 @@ curl_socket_t win32_stdin_read_thread(void)
     }
 
     /* Connect to the thread and rearrange our own STDIN handles */
-    socket_r = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
+    socket_r = CURL_SOCKET(AF_INET, SOCK_STREAM, IPPROTO_TCP);
     if(socket_r == CURL_SOCKET_BAD) {
       errorf("socket error: %08lx", GetLastError());
       break;
diff --git a/tests/libtest/lib1960.c b/tests/libtest/lib1960.c
index 5cdc022426..1ee9277bef 100644
--- a/tests/libtest/lib1960.c
+++ b/tests/libtest/lib1960.c
@@ -96,7 +96,7 @@ static CURLcode test_lib1960(const char *URL)
    * over this socket as "already connected" to libcurl and make sure that
    * this works.
    */
-  client_fd = socket(AF_INET, SOCK_STREAM, 0);
+  client_fd = CURL_SOCKET(AF_INET, SOCK_STREAM, 0);
   if(client_fd == CURL_SOCKET_BAD) {
     curl_mfprintf(stderr, "socket creation error\n");
     goto test_cleanup;
diff --git a/tests/libtest/lib500.c b/tests/libtest/lib500.c
index 0586c1407f..7081ec625d 100644
--- a/tests/libtest/lib500.c
+++ b/tests/libtest/lib500.c
@@ -35,7 +35,7 @@ static curl_socket_t tst_opensocket(void *clientp,
   (void)clientp;
   (void)purpose;
   curl_mprintf("[OPEN] counter: %d\n", ++testcounter);
-  return socket(addr->family, addr->socktype, addr->protocol);
+  return CURL_SOCKET(addr->family, addr->socktype, addr->protocol);
 }
 
 static int tst_closesocket(void *clientp, curl_socket_t sock)
diff --git a/tests/server/.checksrc b/tests/server/.checksrc
index 8b1bcabe77..be8f12cec0 100644
--- a/tests/server/.checksrc
+++ b/tests/server/.checksrc
@@ -1 +1,7 @@
+allowfunc accept
+allowfunc freeaddrinfo
+allowfunc getaddrinfo
+allowfunc recv
+allowfunc send
+allowfunc socket
 allowfunc strtoul