cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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tcp_inq.c (4204B)

      1// SPDX-License-Identifier: GPL-2.0-only
      2/*
      3 * Copyright 2018 Google Inc.
      4 * Author: Soheil Hassas Yeganeh (soheil@google.com)
      5 *
      6 * Simple example on how to use TCP_INQ and TCP_CM_INQ.
      7 */
      8#define _GNU_SOURCE
      9
     10#include <error.h>
     11#include <netinet/in.h>
     12#include <netinet/tcp.h>
     13#include <pthread.h>
     14#include <stdio.h>
     15#include <errno.h>
     16#include <stdlib.h>
     17#include <string.h>
     18#include <sys/socket.h>
     19#include <unistd.h>
     20
     21#ifndef TCP_INQ
     22#define TCP_INQ 36
     23#endif
     24
     25#ifndef TCP_CM_INQ
     26#define TCP_CM_INQ TCP_INQ
     27#endif
     28
     29#define BUF_SIZE 8192
     30#define CMSG_SIZE 32
     31
     32static int family = AF_INET6;
     33static socklen_t addr_len = sizeof(struct sockaddr_in6);
     34static int port = 4974;
     35
     36static void setup_loopback_addr(int family, struct sockaddr_storage *sockaddr)
     37{
     38	struct sockaddr_in6 *addr6 = (void *) sockaddr;
     39	struct sockaddr_in *addr4 = (void *) sockaddr;
     40
     41	switch (family) {
     42	case PF_INET:
     43		memset(addr4, 0, sizeof(*addr4));
     44		addr4->sin_family = AF_INET;
     45		addr4->sin_addr.s_addr = htonl(INADDR_LOOPBACK);
     46		addr4->sin_port = htons(port);
     47		break;
     48	case PF_INET6:
     49		memset(addr6, 0, sizeof(*addr6));
     50		addr6->sin6_family = AF_INET6;
     51		addr6->sin6_addr = in6addr_loopback;
     52		addr6->sin6_port = htons(port);
     53		break;
     54	default:
     55		error(1, 0, "illegal family");
     56	}
     57}
     58
     59void *start_server(void *arg)
     60{
     61	int server_fd = (int)(unsigned long)arg;
     62	struct sockaddr_in addr;
     63	socklen_t addrlen = sizeof(addr);
     64	char *buf;
     65	int fd;
     66	int r;
     67
     68	buf = malloc(BUF_SIZE);
     69
     70	for (;;) {
     71		fd = accept(server_fd, (struct sockaddr *)&addr, &addrlen);
     72		if (fd == -1) {
     73			perror("accept");
     74			break;
     75		}
     76		do {
     77			r = send(fd, buf, BUF_SIZE, 0);
     78		} while (r < 0 && errno == EINTR);
     79		if (r < 0)
     80			perror("send");
     81		if (r != BUF_SIZE)
     82			fprintf(stderr, "can only send %d bytes\n", r);
     83		/* TCP_INQ can overestimate in-queue by one byte if we send
     84		 * the FIN packet. Sleep for 1 second, so that the client
     85		 * likely invoked recvmsg().
     86		 */
     87		sleep(1);
     88		close(fd);
     89	}
     90
     91	free(buf);
     92	close(server_fd);
     93	pthread_exit(0);
     94}
     95
     96int main(int argc, char *argv[])
     97{
     98	struct sockaddr_storage listen_addr, addr;
     99	int c, one = 1, inq = -1;
    100	pthread_t server_thread;
    101	char cmsgbuf[CMSG_SIZE];
    102	struct iovec iov[1];
    103	struct cmsghdr *cm;
    104	struct msghdr msg;
    105	int server_fd, fd;
    106	char *buf;
    107
    108	while ((c = getopt(argc, argv, "46p:")) != -1) {
    109		switch (c) {
    110		case '4':
    111			family = PF_INET;
    112			addr_len = sizeof(struct sockaddr_in);
    113			break;
    114		case '6':
    115			family = PF_INET6;
    116			addr_len = sizeof(struct sockaddr_in6);
    117			break;
    118		case 'p':
    119			port = atoi(optarg);
    120			break;
    121		}
    122	}
    123
    124	server_fd = socket(family, SOCK_STREAM, 0);
    125	if (server_fd < 0)
    126		error(1, errno, "server socket");
    127	setup_loopback_addr(family, &listen_addr);
    128	if (setsockopt(server_fd, SOL_SOCKET, SO_REUSEADDR,
    129		       &one, sizeof(one)) != 0)
    130		error(1, errno, "setsockopt(SO_REUSEADDR)");
    131	if (bind(server_fd, (const struct sockaddr *)&listen_addr,
    132		 addr_len) == -1)
    133		error(1, errno, "bind");
    134	if (listen(server_fd, 128) == -1)
    135		error(1, errno, "listen");
    136	if (pthread_create(&server_thread, NULL, start_server,
    137			   (void *)(unsigned long)server_fd) != 0)
    138		error(1, errno, "pthread_create");
    139
    140	fd = socket(family, SOCK_STREAM, 0);
    141	if (fd < 0)
    142		error(1, errno, "client socket");
    143	setup_loopback_addr(family, &addr);
    144	if (connect(fd, (const struct sockaddr *)&addr, addr_len) == -1)
    145		error(1, errno, "connect");
    146	if (setsockopt(fd, SOL_TCP, TCP_INQ, &one, sizeof(one)) != 0)
    147		error(1, errno, "setsockopt(TCP_INQ)");
    148
    149	msg.msg_name = NULL;
    150	msg.msg_namelen = 0;
    151	msg.msg_iov = iov;
    152	msg.msg_iovlen = 1;
    153	msg.msg_control = cmsgbuf;
    154	msg.msg_controllen = sizeof(cmsgbuf);
    155	msg.msg_flags = 0;
    156
    157	buf = malloc(BUF_SIZE);
    158	iov[0].iov_base = buf;
    159	iov[0].iov_len = BUF_SIZE / 2;
    160
    161	if (recvmsg(fd, &msg, 0) != iov[0].iov_len)
    162		error(1, errno, "recvmsg");
    163	if (msg.msg_flags & MSG_CTRUNC)
    164		error(1, 0, "control message is truncated");
    165
    166	for (cm = CMSG_FIRSTHDR(&msg); cm; cm = CMSG_NXTHDR(&msg, cm))
    167		if (cm->cmsg_level == SOL_TCP && cm->cmsg_type == TCP_CM_INQ)
    168			inq = *((int *) CMSG_DATA(cm));
    169
    170	if (inq != BUF_SIZE - iov[0].iov_len) {
    171		fprintf(stderr, "unexpected inq: %d\n", inq);
    172		exit(1);
    173	}
    174
    175	printf("PASSED\n");
    176	free(buf);
    177	close(fd);
    178	return 0;
    179}