FTL/src/syscalls/sendto.c

46 lines
1.4 KiB
C

/* Pi-hole: A black hole for Internet advertisements
* (c) 2020 Pi-hole, LLC (https://pi-hole.net)
* Network-wide ad blocking via your own hardware.
*
* FTL Engine
* Pi-hole syscall implementation for sendto
*
* This file is copyright under the latest version of the EUPL.
* Please see LICENSE file for your rights under this license. */
#include "../FTL.h"
//#include "syscalls.h" is implicitly done in FTL.h
#include "../log.h"
#include <sys/types.h>
#include <sys/socket.h>
#undef sendto
ssize_t FTLsendto(int sockfd, void *buf, size_t len, int flags, const struct sockaddr *dest_addr, socklen_t addrlen, const char *file, const char *func, const int line)
{
ssize_t ret = 0;
do
{
// Reset errno before trying to write
errno = 0;
ret = sendto(sockfd, buf, len, flags, dest_addr, addrlen);
}
// Try again if the last accept() call failed due to an interruption by an
// incoming signal
while(ret < 0 && errno == EINTR);
// Backup errno value
const int _errno = errno;
// Final error checking (may have failed for some other reason then an
// EINTR = interrupted system call), also ignore EPROTONOSUPPORT (ARP scanning)
// and EPERM + ENOKEY (DHCP probing)
if(ret < 0 && errno != EPROTONOSUPPORT && errno != EPERM && errno != ENOKEY)
logg("WARN: Could not sendto() in %s() (%s:%i): %s",
func, file, line, strerror(errno));
// Restore errno value
errno = _errno;
return ret;
}