compat: replace recvmsg()

compat/recvmsg.c

+/*****************************************************************************
+ * recvmsg.c: POSIX recvmsg() replacement
+ *****************************************************************************
+ * Copyright © 2016 Rémi Denis-Courmont
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU Lesser General Public License as published by
+ * the Free Software Foundation; either version 2.1 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this program; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
+ *****************************************************************************/
+
+#ifdef HAVE_CONFIG_H
+# include <config.h>
+#endif
+
+#ifdef _WIN32
+# include <errno.h>
+# include <stdlib.h>
+# include <mswsock.h>
+
+ssize_t recvmsg(int fd, struct msghdr *msg, int flags)
+{
+    if (msg->msg_controllen != 0)
+    {
+        errno = ENOSYS;
+        return -1;
+    }
+
+    if (msg->msg_iovlen > IOV_MAX)
+    {
+        errno = EINVAL;
+        return -1;
+    }
+
+    WSABUF *buf = malloc(msg->msg_iovlen * sizeof (*buf));
+    if (buf == NULL)
+        return -1;
+
+    for (unsigned i = 0; i < msg->msg_iovlen; i++)
+    {
+        buf[i].len = msg->msg_iov[i].iov_len;
+        buf[i].buf = msg->msg_iov[i].iov_base;
+    }
+
+    DWORD dwFlags = flags;
+    INT fromlen = msg->msg_namelen;
+    DWORD rcvd;
+    int ret = WSARecvFrom(fd, buf, msg->msg_iovlen, &rcvd, &dwFlags,
+                          msg->msg_name, &fromlen, NULL, NULL);
+    free(buf);
+
+    if (ret == 0)
+    {
+        msg->msg_namelen = fromlen;
+        msg->msg_flags = dwFlags;
+        return rcvd;
+    }
+
+    switch (WSAGetLastError())
+    {
+        case WSAEWOULDBLOCK:
+            errno = EAGAIN;
+            break;
+    }
+    return -1;
+}
+#endif

configure.ac

@@ -565,7 +565,7 @@ need_libc=false
 dnl Check for usual libc functions
 AC_CHECK_DECLS([nanosleep],,,[#include <time.h>])
 AC_CHECK_FUNCS([daemon fcntl flock fstatvfs fork getenv getpwuid_r isatty lstat memalign mkostemp mmap open_memstream openat pread posix_fadvise posix_madvise setlocale stricmp strnicmp strptime uselocale pthread_cond_timedwait_monotonic_np pthread_condattr_setclock])
-AC_REPLACE_FUNCS([atof atoll dirfd fdopendir ffsll flockfile fsync getdelim getpid lldiv nrand48 poll posix_memalign rewind sendmsg setenv strcasecmp strcasestr strdup strlcpy strndup strnlen strnstr strsep strtof strtok_r strtoll swab tdestroy timegm timespec_get strverscmp])
+AC_REPLACE_FUNCS([atof atoll dirfd fdopendir ffsll flockfile fsync getdelim getpid lldiv nrand48 poll posix_memalign recvmsg rewind sendmsg setenv strcasecmp strcasestr strdup strlcpy strndup strnlen strnstr strsep strtof strtok_r strtoll swab tdestroy timegm timespec_get strverscmp])
 AC_CHECK_FUNCS(fdatasync,,
   [AC_DEFINE(fdatasync, fsync, [Alias fdatasync() to fsync() if missing.])
 ])

include/vlc_fixups.h

@@ -365,6 +365,11 @@ struct msghdr
 };
 #endif
 
+#ifndef HAVE_RECVMSG
+struct msghdr;
+ssize_t recvmsg(int, struct msghdr *, int);
+#endif
+
 #ifndef HAVE_SENDMSG
 struct msghdr;
 ssize_t sendmsg(int, const struct msghdr *, int);