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| | // SPDX-License-Identifier: GPL-2.0
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <errno.h>
#include <sys/types.h>
#include <netinet/in.h>
#include <arpa/inet.h>
int tcp_peek_offset_probe(sa_family_t af)
{
int optv = 0;
int ret = 0;
int s;
s = socket(af, SOCK_STREAM | SOCK_CLOEXEC, IPPROTO_TCP);
if (s < 0) {
perror("Temporary TCP socket creation failed");
} else {
if (!setsockopt(s, SOL_SOCKET, SO_PEEK_OFF, &optv, sizeof(int)))
ret = 1;
close(s);
}
return ret;
}
static void tcp_peek_offset_set(int s, int offset)
{
if (setsockopt(s, SOL_SOCKET, SO_PEEK_OFF, &offset, sizeof(offset)))
perror("Failed to set SO_PEEK_OFF value\n");
}
static int tcp_peek_offset_get(int s)
{
int offset;
socklen_t len = sizeof(offset);
if (getsockopt(s, SOL_SOCKET, SO_PEEK_OFF, &offset, &len))
perror("Failed to get SO_PEEK_OFF value\n");
return offset;
}
static int tcp_peek_offset_test(void)
{
struct sockaddr a = { AF_INET, {0, }};
int err = EXIT_FAILURE;
int s[2] = {0, 0};
int recv_sock = 0;
int offset = 0;
ssize_t len;
char buf;
s[0] = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
s[1] = socket(AF_INET, SOCK_STREAM | SOCK_NONBLOCK, IPPROTO_TCP);
if (s[0] < 0 || s[1] < 0) {
perror("Temporary probe socket creation failed\n");
goto out;
}
if (0 > bind(s[0], &a, sizeof(a))) {
perror("Temporary probe socket bind() failed\n");
goto out;
}
if (0 > getsockname(s[0], &a, &((socklen_t) { sizeof(a) }))) {
perror("Temporary probe socket getsockname() failed\n");
goto out;
}
if (0 > listen(s[0], 0)) {
perror("Temporary probe socket listen() failed\n");
goto out;
}
if (0 <= connect(s[1], &a, sizeof(a)) || errno != EINPROGRESS) {
perror("Temporary probe socket connect() failed\n");
goto out;
}
recv_sock = accept(s[0], NULL, NULL);
if (recv_sock <= 0) {
perror("Temporary probe socket accept() failed\n");
goto out;
}
/* Some basic tests of getting/setting offset */
offset = tcp_peek_offset_get(recv_sock);
if (offset != -1) {
perror("Initial value of socket offset not -1\n");
goto out;
}
tcp_peek_offset_set(recv_sock, 0);
offset = tcp_peek_offset_get(recv_sock);
if (offset != 0) {
perror("Failed to set socket offset to 0\n");
goto out;
}
/* Transfer a message */
if (0 >= send(s[1], (char *)("ab"), 2, 0) || errno != EINPROGRESS) {
perror("Temporary probe socket send() failed\n");
goto out;
}
/* Read first byte */
len = recv(recv_sock, &buf, 1, MSG_PEEK);
if (len != 1 || buf != 'a') {
perror("Failed to read first byte of message\n");
goto out;
}
offset = tcp_peek_offset_get(recv_sock);
if (offset != 1) {
perror("Offset not forwarded correctly at first byte\n");
goto out;
}
/* Try to read beyond last byte */
len = recv(recv_sock, &buf, 2, MSG_PEEK);
if (len != 1 || buf != 'b') {
perror("Failed to read last byte of message\n");
goto out;
}
offset = tcp_peek_offset_get(recv_sock);
if (offset != 2) {
perror("Offset not forwarded correctly at last byte\n");
goto out;
}
/* Flush message */
len = recv(recv_sock, NULL, 2, MSG_TRUNC);
if (len != 2) {
perror("Failed to flush message\n");
goto out;
}
offset = tcp_peek_offset_get(recv_sock);
if (offset != 0) {
perror("Offset not reverted correctly after flush\n");
goto out;
}
printf("TCP with MSG_PEEK_OFF works correctly\n");
err = EXIT_SUCCESS;
out:
close(recv_sock);
close(s[1]);
close(s[0]);
return err;
}
int main(int argc, char *argv[])
{
int cap4 = 0, cap6 = 0;
cap4 = tcp_peek_offset_probe(AF_INET);
if (!cap4)
printf("SO_PEEK_OFF not supported for TCP/IPv4\n");
cap6 = tcp_peek_offset_probe(AF_INET6);
if (!cap6)
printf("SO_PEEK_OFF not supported for TCP/IPv6\n");
if (!cap4 || !cap6)
exit(EXIT_SUCCESS);
exit(tcp_peek_offset_test());
}
|