From: Tatsuhiro Tsujikawa <tatsuhiro.t@gmail.com>
Date: Fri, 10 Jun 2022 07:09:39 +0000 (+0200)
Subject: ngtcp2: build without sendmsg
X-Git-Tag: curl-7_84_0~60
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=927ede7edcb7b05b8e8bbf9ced6aed523ae594a7;p=thirdparty%2Fcurl.git

ngtcp2: build without sendmsg

Closes #8981
---

diff --git a/configure.ac b/configure.ac
index ce66b5592f..c74d7df2fa 100644
--- a/configure.ac
+++ b/configure.ac
@@ -3446,6 +3446,7 @@ AC_CHECK_FUNCS([fnmatch \
   mach_absolute_time \
   pipe \
   sched_yield \
+  sendmsg \
   setlocale \
   setmode \
   setrlimit \
diff --git a/lib/vquic/ngtcp2.c b/lib/vquic/ngtcp2.c
index 5460048858..60912044a1 100644
--- a/lib/vquic/ngtcp2.c
+++ b/lib/vquic/ngtcp2.c
@@ -728,7 +728,7 @@ CURLcode Curl_quic_connect(struct Curl_easy *data,
 
   ngtcp2_connection_close_error_default(&qs->last_error);
 
-#if defined(__linux__) && defined(UDP_SEGMENT)
+#if defined(__linux__) && defined(UDP_SEGMENT) & defined(HAVE_SENDMSG)
   qs->no_gso = FALSE;
 #else
   qs->no_gso = TRUE;
@@ -1647,9 +1647,10 @@ static CURLcode do_sendmsg(size_t *psent, struct Curl_easy *data, int sockfd,
                            struct quicsocket *qs, const uint8_t *pkt,
                            size_t pktlen, size_t gsolen)
 {
+#ifdef HAVE_SENDMSG
   struct iovec msg_iov = {(void *)pkt, pktlen};
   struct msghdr msg = {0};
-  uint8_t msg_ctrl[CMSG_SPACE(sizeof(uint16_t))] = {0};
+  uint8_t msg_ctrl[32];
   size_t ctrllen = 0;
   ssize_t sent;
 #if defined(__linux__) && defined(UDP_SEGMENT)
@@ -1658,6 +1659,8 @@ static CURLcode do_sendmsg(size_t *psent, struct Curl_easy *data, int sockfd,
 
   *psent = 0;
 
+  assert(sizeof(msg_ctrl) >= CMSG_SPACE(sizeof(uint16_t)));
+
   msg.msg_iov = &msg_iov;
   msg.msg_iovlen = 1;
 
@@ -1708,6 +1711,31 @@ static CURLcode do_sendmsg(size_t *psent, struct Curl_easy *data, int sockfd,
   else {
     assert(pktlen == (size_t)sent);
   }
+#else
+  ssize_t sent;
+  (void)qs;
+  (void)gsolen;
+
+  *psent = 0;
+
+  while((sent = send(sockfd, (const char *)pkt, pktlen, 0)) == -1 &&
+        SOCKERRNO == EINTR)
+    ;
+
+  if(sent == -1) {
+    if(SOCKERRNO == EAGAIN || SOCKERRNO == EWOULDBLOCK) {
+      return CURLE_AGAIN;
+    }
+    else {
+      failf(data, "send() returned %zd (errno %d)", sent, SOCKERRNO);
+      if(SOCKERRNO != EMSGSIZE) {
+        return CURLE_SEND_ERROR;
+      }
+      /* UDP datagram is too large; caused by PMTUD. Just let it be
+         lost. */
+    }
+  }
+#endif
 
   *psent = pktlen;