cosmopolitan/libc/sock/recvmsg.c
2022-05-23 15:07:01 -07:00

97 lines
4.4 KiB
C

/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│
│vi: set net ft=c ts=2 sts=2 sw=2 fenc=utf-8 :vi│
╞══════════════════════════════════════════════════════════════════════════════╡
│ Copyright 2020 Justine Alexandra Roberts Tunney │
│ │
│ Permission to use, copy, modify, and/or distribute this software for │
│ any purpose with or without fee is hereby granted, provided that the │
│ above copyright notice and this permission notice appear in all copies. │
│ │
│ THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL │
│ WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED │
│ WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE │
│ AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL │
│ DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR │
│ PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER │
│ TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR │
│ PERFORMANCE OF THIS SOFTWARE. │
╚─────────────────────────────────────────────────────────────────────────────*/
#include "libc/assert.h"
#include "libc/calls/internal.h"
#include "libc/calls/struct/iovec.h"
#include "libc/dce.h"
#include "libc/sock/internal.h"
#include "libc/sock/sock.h"
#include "libc/sock/syscall_fd.internal.h"
#include "libc/str/str.h"
#include "libc/sysv/errfuns.h"
/**
* Sends a message from a socket.
*
* @param fd is the file descriptor returned by socket()
* @param msg is a pointer to a struct msghdr containing all the allocated
* buffers where to store incoming data.
* @param flags MSG_OOB, MSG_DONTROUTE, MSG_PARTIAL, MSG_NOSIGNAL, etc.
* @return number of bytes received, or -1 w/ errno
* @error EINTR, EHOSTUNREACH, ECONNRESET (UDP ICMP Port Unreachable),
* EPIPE (if MSG_NOSIGNAL), EMSGSIZE, ENOTSOCK, EFAULT, etc.
* @asyncsignalsafe
* @restartable (unless SO_RCVTIMEO)
*/
ssize_t recvmsg(int fd, struct msghdr *msg, int flags) {
ssize_t rc, got;
if (IsAsan() && !__asan_is_valid_msghdr(msg)) {
rc = efault();
} else if (!IsWindows()) {
got = sys_recvmsg(fd, msg, flags);
// An address was provided, convert from BSD form
if (msg->msg_name && IsBsd() && got != -1) {
sockaddr2linux(msg->msg_name);
}
rc = got;
} else if (__isfdopen(fd)) {
if (!msg->msg_control) {
if (__isfdkind(fd, kFdSocket)) {
rc = sys_recvfrom_nt(&g_fds.p[fd], msg->msg_iov, msg->msg_iovlen, flags,
msg->msg_name, &msg->msg_namelen);
} else if (__isfdkind(fd, kFdFile) && !msg->msg_name) { /* socketpair */
if (!flags) {
if ((got = sys_read_nt(&g_fds.p[fd], msg->msg_iov, msg->msg_iovlen,
-1)) != -1) {
msg->msg_flags = 0;
rc = got;
} else {
rc = -1;
}
} else {
rc = einval(); // flags not supported on nt
}
} else {
rc = enotsock();
}
} else {
rc = einval(); // control msg not supported on nt
}
} else {
rc = ebadf();
}
#if defined(SYSDEBUG) && _DATATRACE
if (__strace > 0) {
if (!msg || (rc == -1 && errno == EFAULT)) {
DATATRACE("recvmsg(%d, %p, %#x) → %'ld% m", fd, msg, flags, rc);
} else {
kprintf(STRACE_PROLOGUE "recvmsg(%d, [{");
if (msg->msg_namelen)
kprintf(".name=%#.*hhs, ", msg->msg_namelen, msg->msg_name);
if (msg->msg_controllen)
kprintf(".control=%#.*hhs, ", msg->msg_controllen, msg->msg_control);
if (msg->msg_flags) kprintf(".flags=%#x, ", msg->msg_flags);
kprintf(".iov=", fd);
DescribeIov(msg->msg_iov, msg->msg_iovlen, rc != -1 ? rc : 0);
kprintf("}], %#x) → %'ld% m\n", flags, rc);
}
}
#endif
return rc;
}