granicus.if.org Git - strace/blob - tests/inet-cmsg.c

   1 /*
   2  * Copyright (c) 2015-2016 Dmitry V. Levin <ldv@altlinux.org>
   3  * Copyright (c) 2015-2018 The strace developers.
   4  * All rights reserved.
   5  *
   6  * SPDX-License-Identifier: GPL-2.0-or-later
   7  */
   8
   9 #include "tests.h"
  10 #include <assert.h>
  11 #include <fcntl.h>
  12 #include <stdio.h>
  13 #include <stdint.h>
  14 #include <unistd.h>
  15 #include <sys/socket.h>
  16 #include <netinet/in.h>
  17 #include <arpa/inet.h>
  18
  19 static void
  20 print_pktinfo(const struct cmsghdr *c)
  21 {
  22         printf("IP_PKTINFO, cmsg_data={ipi_ifindex=%s"
  23                ", ipi_spec_dst=inet_addr(\"%s\")"
  24                ", ipi_addr=inet_addr(\"%s\")}",
  25                IFINDEX_LO_STR, "127.0.0.1", "127.0.0.1");
  26 }
  27
  28 static void
  29 print_ttl(const struct cmsghdr *c)
  30 {
  31         const unsigned int *ttl = (const unsigned int *) CMSG_DATA(c);
  32
  33         printf("IP_TTL, cmsg_data=[%u]", *ttl);
  34 }
  35
  36 static void
  37 print_tos(const struct cmsghdr *c)
  38 {
  39         const uint8_t *tos = (const uint8_t *) CMSG_DATA(c);
  40
  41         printf("IP_TOS, cmsg_data=[%#x]", *tos);
  42 }
  43
  44 static void
  45 print_opts(const char *name, const struct cmsghdr *c)
  46 {
  47         const unsigned char *opts = (const unsigned char *) CMSG_DATA(c);
  48         const size_t len = c->cmsg_len - CMSG_ALIGN(sizeof(*c));
  49
  50         printf("%s", name);
  51         if (len) {
  52                 printf(", cmsg_data=[");
  53                 size_t i;
  54                 for (i = 0; i < len; ++i)
  55                         printf("%s0x%02x", i ? ", " : "", opts[i]);
  56                 printf("]");
  57         }
  58 }
  59
  60 #ifdef IP_ORIGDSTADDR
  61 static void
  62 print_origdstaddr(const struct cmsghdr *c)
  63 {
  64         const struct sockaddr_in *sin =
  65                 (const struct sockaddr_in *) CMSG_DATA(c);
  66
  67         printf("IP_ORIGDSTADDR, cmsg_data={sa_family=AF_INET, sin_port=htons(%u)"
  68                ", sin_addr=inet_addr(\"127.0.0.1\")}", ntohs(sin->sin_port));
  69 }
  70 #endif
  71
  72 int
  73 main(void)
  74 {
  75         int i;
  76         while ((i = open("/dev/null", O_RDWR)) < 3)
  77                 assert(i >= 0);
  78         assert(!close(0));
  79         assert(!close(3));
  80
  81         if (socket(AF_INET, SOCK_DGRAM, 0))
  82                 perror_msg_and_skip("socket");
  83         struct sockaddr_in addr = {
  84                 .sin_family = AF_INET,
  85                 .sin_addr.s_addr = htonl(INADDR_LOOPBACK)
  86         };
  87         socklen_t len = sizeof(addr);
  88         if (bind(0, (struct sockaddr *) &addr, len))
  89                 perror_msg_and_skip("bind");
  90         assert(!getsockname(0, (struct sockaddr *) &addr, &len));
  91
  92         assert(socket(AF_INET, SOCK_DGRAM, 0) == 3);
  93         assert(!connect(3, (struct sockaddr *) &addr, len));
  94
  95         const int opt_1 = htonl(0x01000000);
  96 #define SETSOCKOPT(fd, name) assert(!setsockopt(fd, IPPROTO_IP, (name), &opt_1, sizeof(opt_1)))
  97         SETSOCKOPT(3, IP_OPTIONS);
  98         SETSOCKOPT(0, IP_PKTINFO);
  99         SETSOCKOPT(0, IP_RECVTTL);
 100         SETSOCKOPT(0, IP_RECVTOS);
 101         SETSOCKOPT(0, IP_RECVOPTS);
 102         SETSOCKOPT(0, IP_RETOPTS);
 103 #ifdef IP_RECVORIGDSTADDR
 104         SETSOCKOPT(0, IP_RECVORIGDSTADDR);
 105 #endif
 106
 107         static const char data[] = "data";
 108         const size_t size = sizeof(data) - 1;
 109         assert(send(3, data, size, 0) == (int) size);
 110         assert(!close(3));
 111
 112         char buf[size];
 113         struct iovec iov = {
 114                 .iov_base = buf,
 115                 .iov_len = sizeof(buf)
 116         };
 117         struct cmsghdr control[16];
 118         struct msghdr mh = {
 119                 .msg_name = &addr,
 120                 .msg_namelen = len,
 121                 .msg_iov = &iov,
 122                 .msg_iovlen = 1,
 123                 .msg_control = control,
 124                 .msg_controllen = sizeof(control)
 125         };
 126
 127         assert(recvmsg(0, &mh, 0) == (int) size);
 128         assert(!close(0));
 129
 130         printf("recvmsg(0, {msg_name={sa_family=AF_INET, sin_port=htons(%u)"
 131                ", sin_addr=inet_addr(\"127.0.0.1\")}, msg_namelen=%u"
 132                ", msg_iov=[{iov_base=\"%s\", iov_len=%u}], msg_iovlen=1"
 133                ", msg_control=[",
 134                ntohs(addr.sin_port), (unsigned) mh.msg_namelen,
 135                data, (unsigned) size);
 136
 137         struct cmsghdr *c;
 138         for (c = CMSG_FIRSTHDR(&mh); c; c = CMSG_NXTHDR(&mh, c)) {
 139                 if (IPPROTO_IP != c->cmsg_level)
 140                         continue;
 141                 if (c != control)
 142                         printf(", ");
 143                 printf("{cmsg_len=%lu, cmsg_level=SOL_IP, cmsg_type=",
 144                        (unsigned long) c->cmsg_len);
 145                 switch (c->cmsg_type) {
 146                         case IP_PKTINFO:
 147                                 print_pktinfo(c);
 148                                 break;
 149                         case IP_TTL:
 150                                 print_ttl(c);
 151                                 break;
 152                         case IP_TOS:
 153                                 print_tos(c);
 154                                 break;
 155                         case IP_RECVOPTS:
 156                                 print_opts("IP_RECVOPTS", c);
 157                                 break;
 158                         case IP_RETOPTS:
 159                                 print_opts("IP_RETOPTS", c);
 160                                 break;
 161 #ifdef IP_ORIGDSTADDR
 162                         case IP_ORIGDSTADDR:
 163                                 print_origdstaddr(c);
 164                                 break;
 165 #endif
 166                         default:
 167                                 printf("%d", c->cmsg_type);
 168                                 break;
 169                 }
 170                 printf("}");
 171         }
 172         printf("], msg_controllen=%lu, msg_flags=0}, 0) = %u\n",
 173                (unsigned long) mh.msg_controllen, (unsigned) size);
 174         puts("+++ exited with 0 +++");
 175
 176         return 0;
 177 }