1  /*
       2   * Check decoding of recvfrom MSG_TRUNC.
       3   *
       4   * Copyright (c) 2019-2021 Dmitry V. Levin <ldv@strace.io>
       5   * All rights reserved.
       6   *
       7   * SPDX-License-Identifier: GPL-2.0-or-later
       8   */
       9  
      10  #include "tests.h"
      11  #include <stdio.h>
      12  #include <sys/socket.h>
      13  
      14  int
      15  main(void)
      16  {
      17  	static const char sbuf[2] = "AB";
      18  	int sv[2];
      19  	TAIL_ALLOC_OBJECT_CONST_PTR(char, rbuf);
      20  
      21  	if (socketpair(AF_UNIX, SOCK_DGRAM, 0, sv))
      22  		perror_msg_and_skip("socketpair");
      23  
      24  	if (send(sv[1], sbuf + 1, 1, 0) != 1)
      25                  perror_msg_and_skip("send");
      26  	if (recvfrom(sv[0], rbuf - 1, 2, MSG_PEEK, NULL, NULL) != 1)
      27  		perror_msg_and_fail("recvfrom");
      28  	printf("recvfrom(%d, \"B\", 2, MSG_PEEK, NULL, NULL) = 1\n", sv[0]);
      29  
      30  	if (recvfrom(sv[0], rbuf, 1, MSG_TRUNC, NULL, NULL) != 1)
      31  		perror_msg_and_skip("recvfrom");
      32  	printf("recvfrom(%d, \"B\", 1, MSG_TRUNC, NULL, NULL) = 1\n", sv[0]);
      33  
      34  	if (send(sv[1], sbuf, 2, 0) != 2)
      35                  perror_msg_and_skip("send");
      36  	if (recvfrom(sv[0], rbuf, 1, MSG_TRUNC, NULL, NULL) != 2)
      37  		perror_msg_and_skip("recvfrom");
      38  	printf("recvfrom(%d, \"A\", 1, MSG_TRUNC, NULL, NULL) = 2\n", sv[0]);
      39  
      40  	puts("+++ exited with 0 +++");
      41  	return 0;
      42  }