/* * Copyright (c) 2015-2016 Dmitry V. Levin * Copyright (c) 2015-2018 The strace developers. * All rights reserved. * * SPDX-License-Identifier: GPL-2.0-or-later */ #include "tests.h" #include #include #include #include #include #include #include #include static void print_pktinfo(const struct cmsghdr *c) { printf("IP_PKTINFO, cmsg_data={ipi_ifindex=%s" ", ipi_spec_dst=inet_addr(\"%s\")" ", ipi_addr=inet_addr(\"%s\")}", IFINDEX_LO_STR, "127.0.0.1", "127.0.0.1"); } static void print_ttl(const struct cmsghdr *c) { const unsigned int *ttl = (const unsigned int *) CMSG_DATA(c); printf("IP_TTL, cmsg_data=[%u]", *ttl); } static void print_tos(const struct cmsghdr *c) { const uint8_t *tos = (const uint8_t *) CMSG_DATA(c); printf("IP_TOS, cmsg_data=[%#x]", *tos); } static void print_opts(const char *name, const struct cmsghdr *c) { const unsigned char *opts = (const unsigned char *) CMSG_DATA(c); const size_t len = c->cmsg_len - CMSG_ALIGN(sizeof(*c)); printf("%s", name); if (len) { printf(", cmsg_data=["); size_t i; for (i = 0; i < len; ++i) printf("%s0x%02x", i ? ", " : "", opts[i]); printf("]"); } } #ifdef IP_ORIGDSTADDR static void print_origdstaddr(const struct cmsghdr *c) { const struct sockaddr_in *sin = (const struct sockaddr_in *) CMSG_DATA(c); printf("IP_ORIGDSTADDR, cmsg_data={sa_family=AF_INET, sin_port=htons(%u)" ", sin_addr=inet_addr(\"127.0.0.1\")}", ntohs(sin->sin_port)); } #endif int main(void) { int i; while ((i = open("/dev/null", O_RDWR)) < 3) assert(i >= 0); assert(!close(0)); assert(!close(3)); if (socket(AF_INET, SOCK_DGRAM, 0)) perror_msg_and_skip("socket"); struct sockaddr_in addr = { .sin_family = AF_INET, .sin_addr.s_addr = htonl(INADDR_LOOPBACK) }; socklen_t len = sizeof(addr); if (bind(0, (struct sockaddr *) &addr, len)) perror_msg_and_skip("bind"); assert(!getsockname(0, (struct sockaddr *) &addr, &len)); assert(socket(AF_INET, SOCK_DGRAM, 0) == 3); assert(!connect(3, (struct sockaddr *) &addr, len)); const int opt_1 = htonl(0x01000000); #define SETSOCKOPT(fd, name) assert(!setsockopt(fd, IPPROTO_IP, (name), &opt_1, sizeof(opt_1))) SETSOCKOPT(3, IP_OPTIONS); SETSOCKOPT(0, IP_PKTINFO); SETSOCKOPT(0, IP_RECVTTL); SETSOCKOPT(0, IP_RECVTOS); SETSOCKOPT(0, IP_RECVOPTS); SETSOCKOPT(0, IP_RETOPTS); #ifdef IP_RECVORIGDSTADDR SETSOCKOPT(0, IP_RECVORIGDSTADDR); #endif static const char data[] = "data"; const size_t size = sizeof(data) - 1; assert(send(3, data, size, 0) == (int) size); assert(!close(3)); char buf[size]; struct iovec iov = { .iov_base = buf, .iov_len = sizeof(buf) }; struct cmsghdr control[16]; struct msghdr mh = { .msg_name = &addr, .msg_namelen = len, .msg_iov = &iov, .msg_iovlen = 1, .msg_control = control, .msg_controllen = sizeof(control) }; assert(recvmsg(0, &mh, 0) == (int) size); assert(!close(0)); printf("recvmsg(0, {msg_name={sa_family=AF_INET, sin_port=htons(%u)" ", sin_addr=inet_addr(\"127.0.0.1\")}, msg_namelen=%u" ", msg_iov=[{iov_base=\"%s\", iov_len=%u}], msg_iovlen=1" ", msg_control=[", ntohs(addr.sin_port), (unsigned) mh.msg_namelen, data, (unsigned) size); struct cmsghdr *c; for (c = CMSG_FIRSTHDR(&mh); c; c = CMSG_NXTHDR(&mh, c)) { if (IPPROTO_IP != c->cmsg_level) continue; if (c != control) printf(", "); printf("{cmsg_len=%lu, cmsg_level=SOL_IP, cmsg_type=", (unsigned long) c->cmsg_len); switch (c->cmsg_type) { case IP_PKTINFO: print_pktinfo(c); break; case IP_TTL: print_ttl(c); break; case IP_TOS: print_tos(c); break; case IP_RECVOPTS: print_opts("IP_RECVOPTS", c); break; case IP_RETOPTS: print_opts("IP_RETOPTS", c); break; #ifdef IP_ORIGDSTADDR case IP_ORIGDSTADDR: print_origdstaddr(c); break; #endif default: printf("%d", c->cmsg_type); break; } printf("}"); } printf("], msg_controllen=%lu, msg_flags=0}, 0) = %u\n", (unsigned long) mh.msg_controllen, (unsigned) size); puts("+++ exited with 0 +++"); return 0; }