Fix connect timeout not accounting for DNS resolution time (#810)

* Initial plan

* Fix connect timeout not accounting for DNS resolution time

The ConnectTimeout function previously only applied the timeout to the
TCP connect phase (poll/select), but DNS resolution via getaddrinfo()
had no timeout applied. On platforms like Android with no network,
getaddrinfo() can block for 30-40 seconds, making user-set
connect_timeout and timeout values ineffective.

Changes:
- ConnectTimeout now tracks elapsed time for DNS resolution and
  subtracts it from the TCP connect timeout. If DNS takes longer
  than the timeout, it returns ETIMEDOUT immediately.
- http_client_connect adjusts SSL handshake timeout by subtracting
  time already spent on DNS+TCP connect.
- http_client_exec checks overall request timeout after connect,
  handling cases where connect took longer than expected.
- Updated build files (CMakeLists.txt, Makefile) to link htime.c
  with all targets that use hsocket.c.

Co-authored-by: ithewei <26049660+ithewei@users.noreply.github.com>

* Address code review: use consistent error handling and fail immediately on SSL timeout

Co-authored-by: ithewei <26049660+ithewei@users.noreply.github.com>

* Use CHECK_TIMEOUT after connect and add hsocket.c+htime.c to nslookup target

- Replace inline timeout check with CHECK_TIMEOUT macro by moving
  variable declarations before the connect: label to avoid crossing
  initializations with goto.
- Add hsocket.c and htime.c to nslookup CMake target for Windows
  link compatibility (dns.c calls WSAInit from hsocket.c).

Co-authored-by: ithewei <26049660+ithewei@users.noreply.github.com>

* Add explicit closesocket(connfd) in ConnectTimeout before returning -ETIMEDOUT

When DNS resolution exhausts the timeout budget, explicitly close the
socket with closesocket() and return -ETIMEDOUT directly, instead of
relying on socket_errno_negative() which reads errno indirectly and
could return the wrong error code on Windows.

Co-authored-by: ithewei <26049660+ithewei@users.noreply.github.com>

---------

Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com>
Co-authored-by: ithewei <26049660+ithewei@users.noreply.github.com>

Author: Copilot

Makefile

@@ -268,7 +268,7 @@ unittest: prepare
 	$(CXX) -g -Wall -O0 -std=c++11 -I. -Ibase            -o bin/hthread_test      unittest/hthread_test.cpp     -pthread
 	$(CC)  -g -Wall -O0 -std=c99   -I. -Ibase            -o bin/hmutex_test       unittest/hmutex_test.c        base/htime.c   -pthread
 	$(CC)  -g -Wall -O0 -std=c99   -I. -Ibase            -o bin/connect_test      unittest/connect_test.c       base/hsocket.c base/htime.c
-	$(CC)  -g -Wall -O0 -std=c99   -I. -Ibase            -o bin/socketpair_test   unittest/socketpair_test.c    base/hsocket.c
+	$(CC)  -g -Wall -O0 -std=c99   -I. -Ibase            -o bin/socketpair_test   unittest/socketpair_test.c    base/hsocket.c base/htime.c
 	$(CC)  -g -Wall -O0 -std=c99   -I. -Iutil            -o bin/base64            unittest/base64_test.c        util/base64.c
 	$(CC)  -g -Wall -O0 -std=c99   -I. -Iutil            -o bin/md5               unittest/md5_test.c           util/md5.c
 	$(CC)  -g -Wall -O0 -std=c99   -I. -Iutil            -o bin/sha1              unittest/sha1_test.c          util/sha1.c
@@ -282,10 +282,10 @@ unittest: prepare
 	$(CXX) -g -Wall -O0 -std=c++11 -I. -Ibase -Icpputil  -o bin/threadpool_test   unittest/threadpool_test.cpp  -pthread
 	$(CXX) -g -Wall -O0 -std=c++11 -I. -Ibase -Icpputil  -o bin/objectpool_test   unittest/objectpool_test.cpp  -pthread
 	$(CXX) -g -Wall -O0 -std=c++11 -I. -Ibase -Issl -Ievent -Ievpp -Icpputil -Ihttp -Ihttp/client -Ihttp/server -o bin/sizeof_test unittest/sizeof_test.cpp
-	$(CC)  -g -Wall -O0 -std=c99   -I. -Ibase -Iprotocol -o bin/nslookup          unittest/nslookup_test.c      protocol/dns.c  base/hsocket.c
+	$(CC)  -g -Wall -O0 -std=c99   -I. -Ibase -Iprotocol -o bin/nslookup          unittest/nslookup_test.c      protocol/dns.c  base/hsocket.c base/htime.c
 	$(CC)  -g -Wall -O0 -std=c99   -I. -Ibase -Iprotocol -o bin/ping              unittest/ping_test.c          protocol/icmp.c base/hsocket.c base/htime.c -DPRINT_DEBUG
-	$(CC)  -g -Wall -O0 -std=c99   -I. -Ibase -Iprotocol -o bin/ftp               unittest/ftp_test.c           protocol/ftp.c  base/hsocket.c
-	$(CC)  -g -Wall -O0 -std=c99   -I. -Ibase -Iprotocol -Iutil -o bin/sendmail   unittest/sendmail_test.c      protocol/smtp.c base/hsocket.c util/base64.c
+	$(CC)  -g -Wall -O0 -std=c99   -I. -Ibase -Iprotocol -o bin/ftp               unittest/ftp_test.c           protocol/ftp.c  base/hsocket.c base/htime.c
+	$(CC)  -g -Wall -O0 -std=c99   -I. -Ibase -Iprotocol -Iutil -o bin/sendmail   unittest/sendmail_test.c      protocol/smtp.c base/hsocket.c base/htime.c util/base64.c
 
 run-unittest: unittest
 	bash scripts/unittest.sh

base/hsocket.c

@@ -1,6 +1,7 @@
 #include "hsocket.h"
 
 #include "hdef.h"
+#include "htime.h"
 
 #ifdef OS_UNIX
 #include <poll.h>
@@ -339,9 +340,16 @@ int ConnectNonblock(const char* host, int port) {
 }
 
 int ConnectTimeout(const char* host, int port, int ms) {
+    unsigned int start_time = gettick_ms();
     int connfd = Connect(host, port, 1);
     if (connfd < 0) return connfd;
-    return ConnectFDTimeout(connfd, ms);
+    unsigned int elapsed = gettick_ms() - start_time;
+    int remaining = ms - (int)elapsed;
+    if (remaining <= 0) {
+        closesocket(connfd);
+        return -ETIMEDOUT;
+    }
+    return ConnectFDTimeout(connfd, remaining);
 }
 
 #ifdef ENABLE_UDS

http/client/HttpClient.cpp

@@ -211,6 +211,7 @@ int http_client_connect(http_client_t* cli, const char* host, int port, int http
     if (timeout > 0) {
         blocktime = MIN(timeout*1000, blocktime);
     }
+    unsigned int start_time = gettick_ms();
     int connfd = ConnectTimeout(host, port, blocktime);
     if (connfd < 0) {
         hloge("connect %s:%d failed!", host, port);
@@ -241,7 +242,15 @@ int http_client_connect(http_client_t* cli, const char* host, int port, int http
         if (!is_ipaddr(host)) {
             hssl_set_sni_hostname(cli->ssl, host);
         }
-        so_rcvtimeo(connfd, blocktime);
+        unsigned int elapsed = gettick_ms() - start_time;
+        int ssl_timeout = blocktime - (int)elapsed;
+        if (ssl_timeout <= 0) {
+            hssl_free(cli->ssl);
+            cli->ssl = NULL;
+            closesocket(connfd);
+            return NABS(ETIMEDOUT);
+        }
+        so_rcvtimeo(connfd, ssl_timeout);
         int ret = hssl_connect(cli->ssl);
         if (ret != 0) {
             fprintf(stderr, "* ssl handshake failed: %d\n", ret);
@@ -321,6 +330,12 @@ static int http_client_exec(http_client_t* cli, HttpRequest* req, HttpResponse*
         }
     }
 
+    char recvbuf[1024] = {0};
+    char* data = NULL;
+    size_t len  = 0;
+    int total_nsend, nsend, nrecv;
+    total_nsend = nsend = nrecv = 0;
+
     if (connfd <= 0 || cli->host != req->host || cli->port != req->port) {
         cli->host = req->host;
         cli->port = req->port;
@@ -329,15 +344,13 @@ static int http_client_exec(http_client_t* cli, HttpRequest* req, HttpResponse*
         if (connfd < 0) {
             return connfd;
         }
+        CHECK_TIMEOUT
     }
 
     cli->parser->SubmitRequest(req);
-    char recvbuf[1024] = {0};
-    int total_nsend, nsend, nrecv;
-    total_nsend = nsend = nrecv = 0;
 send:
-    char* data = NULL;
-    size_t len  = 0;
+    data = NULL;
+    len  = 0;
     while (cli->parser->GetSendData(&data, &len)) {
         total_nsend = 0;
         while (total_nsend < len) {

unittest/CMakeLists.txt

@@ -28,7 +28,7 @@ target_link_libraries(hmutex_test -lpthread)
 add_executable(connect_test connect_test.c ../base/hsocket.c ../base/htime.c)
 target_include_directories(connect_test PRIVATE .. ../base)
 
-add_executable(socketpair_test socketpair_test.c ../base/hsocket.c)
+add_executable(socketpair_test socketpair_test.c ../base/hsocket.c ../base/htime.c)
 target_include_directories(socketpair_test PRIVATE .. ../base)
 
 # ------util------
@@ -73,17 +73,17 @@ target_include_directories(objectpool_test PRIVATE .. ../base ../cpputil)
 target_link_libraries(objectpool_test -lpthread)
 
 # ------protocol------
-add_executable(nslookup nslookup_test.c ../protocol/dns.c)
+add_executable(nslookup nslookup_test.c ../protocol/dns.c ../base/hsocket.c ../base/htime.c)
 target_include_directories(nslookup PRIVATE .. ../base ../protocol)
 
 add_executable(ping ping_test.c ../protocol/icmp.c ../base/hsocket.c ../base/htime.c)
 target_compile_definitions(ping PRIVATE -DPRINT_DEBUG)
 target_include_directories(ping PRIVATE .. ../base ../protocol)
 
-add_executable(ftp ftp_test.c ../protocol/ftp.c ../base/hsocket.c)
+add_executable(ftp ftp_test.c ../protocol/ftp.c ../base/hsocket.c ../base/htime.c)
 target_include_directories(ftp PRIVATE .. ../base ../protocol)
 
-add_executable(sendmail sendmail_test.c ../protocol/smtp.c ../base/hsocket.c ../util/base64.c)
+add_executable(sendmail sendmail_test.c ../protocol/smtp.c ../base/hsocket.c ../base/htime.c ../util/base64.c)
 target_include_directories(sendmail PRIVATE .. ../base ../protocol ../util)
 
 if(UNIX)