diff options
Diffstat (limited to 'tools/testing/selftests/net/mptcp/mptcp_sockopt.c')
-rw-r--r-- | tools/testing/selftests/net/mptcp/mptcp_sockopt.c | 866 |
1 files changed, 866 insertions, 0 deletions
diff --git a/tools/testing/selftests/net/mptcp/mptcp_sockopt.c b/tools/testing/selftests/net/mptcp/mptcp_sockopt.c new file mode 100644 index 0000000000..926b0be87c --- /dev/null +++ b/tools/testing/selftests/net/mptcp/mptcp_sockopt.c @@ -0,0 +1,866 @@ +// SPDX-License-Identifier: GPL-2.0 + +#define _GNU_SOURCE + +#include <assert.h> +#include <errno.h> +#include <fcntl.h> +#include <limits.h> +#include <string.h> +#include <stdarg.h> +#include <stdbool.h> +#include <stdint.h> +#include <inttypes.h> +#include <stdio.h> +#include <stdlib.h> +#include <strings.h> +#include <time.h> +#include <unistd.h> + +#include <sys/socket.h> +#include <sys/types.h> +#include <sys/wait.h> + +#include <netdb.h> +#include <netinet/in.h> + +#include <linux/tcp.h> + +static int pf = AF_INET; + +#ifndef IPPROTO_MPTCP +#define IPPROTO_MPTCP 262 +#endif +#ifndef SOL_MPTCP +#define SOL_MPTCP 284 +#endif + +#ifndef MPTCP_INFO +struct mptcp_info { + __u8 mptcpi_subflows; + __u8 mptcpi_add_addr_signal; + __u8 mptcpi_add_addr_accepted; + __u8 mptcpi_subflows_max; + __u8 mptcpi_add_addr_signal_max; + __u8 mptcpi_add_addr_accepted_max; + __u32 mptcpi_flags; + __u32 mptcpi_token; + __u64 mptcpi_write_seq; + __u64 mptcpi_snd_una; + __u64 mptcpi_rcv_nxt; + __u8 mptcpi_local_addr_used; + __u8 mptcpi_local_addr_max; + __u8 mptcpi_csum_enabled; + __u32 mptcpi_retransmits; + __u64 mptcpi_bytes_retrans; + __u64 mptcpi_bytes_sent; + __u64 mptcpi_bytes_received; + __u64 mptcpi_bytes_acked; +}; + +struct mptcp_subflow_data { + __u32 size_subflow_data; /* size of this structure in userspace */ + __u32 num_subflows; /* must be 0, set by kernel */ + __u32 size_kernel; /* must be 0, set by kernel */ + __u32 size_user; /* size of one element in data[] */ +} __attribute__((aligned(8))); + +struct mptcp_subflow_addrs { + union { + __kernel_sa_family_t sa_family; + struct sockaddr sa_local; + struct sockaddr_in sin_local; + struct sockaddr_in6 sin6_local; + struct __kernel_sockaddr_storage ss_local; + }; + union { + struct sockaddr sa_remote; + struct sockaddr_in sin_remote; + struct sockaddr_in6 sin6_remote; + struct __kernel_sockaddr_storage ss_remote; + }; +}; + +#define MPTCP_INFO 1 +#define MPTCP_TCPINFO 2 +#define MPTCP_SUBFLOW_ADDRS 3 +#endif + +#ifndef MPTCP_FULL_INFO +struct mptcp_subflow_info { + __u32 id; + struct mptcp_subflow_addrs addrs; +}; + +struct mptcp_full_info { + __u32 size_tcpinfo_kernel; /* must be 0, set by kernel */ + __u32 size_tcpinfo_user; + __u32 size_sfinfo_kernel; /* must be 0, set by kernel */ + __u32 size_sfinfo_user; + __u32 num_subflows; /* must be 0, set by kernel (real subflow count) */ + __u32 size_arrays_user; /* max subflows that userspace is interested in; + * the buffers at subflow_info/tcp_info + * are respectively at least: + * size_arrays * size_sfinfo_user + * size_arrays * size_tcpinfo_user + * bytes wide + */ + __aligned_u64 subflow_info; + __aligned_u64 tcp_info; + struct mptcp_info mptcp_info; +}; + +#define MPTCP_FULL_INFO 4 +#endif + +struct so_state { + struct mptcp_info mi; + struct mptcp_info last_sample; + struct tcp_info tcp_info; + struct mptcp_subflow_addrs addrs; + uint64_t mptcpi_rcv_delta; + uint64_t tcpi_rcv_delta; + bool pkt_stats_avail; +}; + +#ifndef MIN +#define MIN(a, b) ((a) < (b) ? (a) : (b)) +#endif + +static void die_perror(const char *msg) +{ + perror(msg); + exit(1); +} + +static void die_usage(int r) +{ + fprintf(stderr, "Usage: mptcp_sockopt [-6]\n"); + exit(r); +} + +static void xerror(const char *fmt, ...) +{ + va_list ap; + + va_start(ap, fmt); + vfprintf(stderr, fmt, ap); + va_end(ap); + fputc('\n', stderr); + exit(1); +} + +static const char *getxinfo_strerr(int err) +{ + if (err == EAI_SYSTEM) + return strerror(errno); + + return gai_strerror(err); +} + +static void xgetaddrinfo(const char *node, const char *service, + const struct addrinfo *hints, + struct addrinfo **res) +{ + int err = getaddrinfo(node, service, hints, res); + + if (err) { + const char *errstr = getxinfo_strerr(err); + + fprintf(stderr, "Fatal: getaddrinfo(%s:%s): %s\n", + node ? node : "", service ? service : "", errstr); + exit(1); + } +} + +static int sock_listen_mptcp(const char * const listenaddr, + const char * const port) +{ + int sock = -1; + struct addrinfo hints = { + .ai_protocol = IPPROTO_TCP, + .ai_socktype = SOCK_STREAM, + .ai_flags = AI_PASSIVE | AI_NUMERICHOST + }; + + hints.ai_family = pf; + + struct addrinfo *a, *addr; + int one = 1; + + xgetaddrinfo(listenaddr, port, &hints, &addr); + hints.ai_family = pf; + + for (a = addr; a; a = a->ai_next) { + sock = socket(a->ai_family, a->ai_socktype, IPPROTO_MPTCP); + if (sock < 0) + continue; + + if (-1 == setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, &one, + sizeof(one))) + perror("setsockopt"); + + if (bind(sock, a->ai_addr, a->ai_addrlen) == 0) + break; /* success */ + + perror("bind"); + close(sock); + sock = -1; + } + + freeaddrinfo(addr); + + if (sock < 0) + xerror("could not create listen socket"); + + if (listen(sock, 20)) + die_perror("listen"); + + return sock; +} + +static int sock_connect_mptcp(const char * const remoteaddr, + const char * const port, int proto) +{ + struct addrinfo hints = { + .ai_protocol = IPPROTO_TCP, + .ai_socktype = SOCK_STREAM, + }; + struct addrinfo *a, *addr; + int sock = -1; + + hints.ai_family = pf; + + xgetaddrinfo(remoteaddr, port, &hints, &addr); + for (a = addr; a; a = a->ai_next) { + sock = socket(a->ai_family, a->ai_socktype, proto); + if (sock < 0) + continue; + + if (connect(sock, a->ai_addr, a->ai_addrlen) == 0) + break; /* success */ + + die_perror("connect"); + } + + if (sock < 0) + xerror("could not create connect socket"); + + freeaddrinfo(addr); + return sock; +} + +static void parse_opts(int argc, char **argv) +{ + int c; + + while ((c = getopt(argc, argv, "h6")) != -1) { + switch (c) { + case 'h': + die_usage(0); + break; + case '6': + pf = AF_INET6; + break; + default: + die_usage(1); + break; + } + } +} + +static void do_getsockopt_bogus_sf_data(int fd, int optname) +{ + struct mptcp_subflow_data good_data; + struct bogus_data { + struct mptcp_subflow_data d; + char buf[2]; + } bd; + socklen_t olen, _olen; + int ret; + + memset(&bd, 0, sizeof(bd)); + memset(&good_data, 0, sizeof(good_data)); + + olen = sizeof(good_data); + good_data.size_subflow_data = olen; + + ret = getsockopt(fd, SOL_MPTCP, optname, &bd, &olen); + assert(ret < 0); /* 0 size_subflow_data */ + assert(olen == sizeof(good_data)); + + bd.d = good_data; + + ret = getsockopt(fd, SOL_MPTCP, optname, &bd, &olen); + assert(ret == 0); + assert(olen == sizeof(good_data)); + assert(bd.d.num_subflows == 1); + assert(bd.d.size_kernel > 0); + assert(bd.d.size_user == 0); + + bd.d = good_data; + _olen = rand() % olen; + olen = _olen; + ret = getsockopt(fd, SOL_MPTCP, optname, &bd, &olen); + assert(ret < 0); /* bogus olen */ + assert(olen == _olen); /* must be unchanged */ + + bd.d = good_data; + olen = sizeof(good_data); + bd.d.size_kernel = 1; + ret = getsockopt(fd, SOL_MPTCP, optname, &bd, &olen); + assert(ret < 0); /* size_kernel not 0 */ + + bd.d = good_data; + olen = sizeof(good_data); + bd.d.num_subflows = 1; + ret = getsockopt(fd, SOL_MPTCP, optname, &bd, &olen); + assert(ret < 0); /* num_subflows not 0 */ + + /* forward compat check: larger struct mptcp_subflow_data on 'old' kernel */ + bd.d = good_data; + olen = sizeof(bd); + bd.d.size_subflow_data = sizeof(bd); + + ret = getsockopt(fd, SOL_MPTCP, optname, &bd, &olen); + assert(ret == 0); + + /* olen must be truncated to real data size filled by kernel: */ + assert(olen == sizeof(good_data)); + + assert(bd.d.size_subflow_data == sizeof(bd)); + + bd.d = good_data; + bd.d.size_subflow_data += 1; + bd.d.size_user = 1; + olen = bd.d.size_subflow_data + 1; + _olen = olen; + + ret = getsockopt(fd, SOL_MPTCP, optname, &bd, &_olen); + assert(ret == 0); + + /* no truncation, kernel should have filled 1 byte of optname payload in buf[1]: */ + assert(olen == _olen); + + assert(bd.d.size_subflow_data == sizeof(good_data) + 1); + assert(bd.buf[0] == 0); +} + +static void do_getsockopt_mptcp_info(struct so_state *s, int fd, size_t w) +{ + struct mptcp_info i; + socklen_t olen; + int ret; + + olen = sizeof(i); + ret = getsockopt(fd, SOL_MPTCP, MPTCP_INFO, &i, &olen); + + if (ret < 0) + die_perror("getsockopt MPTCP_INFO"); + + s->pkt_stats_avail = olen >= sizeof(i); + + s->last_sample = i; + if (s->mi.mptcpi_write_seq == 0) + s->mi = i; + + assert(s->mi.mptcpi_write_seq + w == i.mptcpi_write_seq); + + s->mptcpi_rcv_delta = i.mptcpi_rcv_nxt - s->mi.mptcpi_rcv_nxt; +} + +static void do_getsockopt_tcp_info(struct so_state *s, int fd, size_t r, size_t w) +{ + struct my_tcp_info { + struct mptcp_subflow_data d; + struct tcp_info ti[2]; + } ti; + int ret, tries = 5; + socklen_t olen; + + do { + memset(&ti, 0, sizeof(ti)); + + ti.d.size_subflow_data = sizeof(struct mptcp_subflow_data); + ti.d.size_user = sizeof(struct tcp_info); + olen = sizeof(ti); + + ret = getsockopt(fd, SOL_MPTCP, MPTCP_TCPINFO, &ti, &olen); + if (ret < 0) + xerror("getsockopt MPTCP_TCPINFO (tries %d, %m)"); + + assert(olen <= sizeof(ti)); + assert(ti.d.size_kernel > 0); + assert(ti.d.size_user == + MIN(ti.d.size_kernel, sizeof(struct tcp_info))); + assert(ti.d.num_subflows == 1); + + assert(olen > (socklen_t)sizeof(struct mptcp_subflow_data)); + olen -= sizeof(struct mptcp_subflow_data); + assert(olen == ti.d.size_user); + + s->tcp_info = ti.ti[0]; + + if (ti.ti[0].tcpi_bytes_sent == w && + ti.ti[0].tcpi_bytes_received == r) + goto done; + + if (r == 0 && ti.ti[0].tcpi_bytes_sent == w && + ti.ti[0].tcpi_bytes_received) { + s->tcpi_rcv_delta = ti.ti[0].tcpi_bytes_received; + goto done; + } + + /* wait and repeat, might be that tx is still ongoing */ + sleep(1); + } while (tries-- > 0); + + xerror("tcpi_bytes_sent %" PRIu64 ", want %zu. tcpi_bytes_received %" PRIu64 ", want %zu", + ti.ti[0].tcpi_bytes_sent, w, ti.ti[0].tcpi_bytes_received, r); + +done: + do_getsockopt_bogus_sf_data(fd, MPTCP_TCPINFO); +} + +static void do_getsockopt_subflow_addrs(struct so_state *s, int fd) +{ + struct sockaddr_storage remote, local; + socklen_t olen, rlen, llen; + int ret; + struct my_addrs { + struct mptcp_subflow_data d; + struct mptcp_subflow_addrs addr[2]; + } addrs; + + memset(&addrs, 0, sizeof(addrs)); + memset(&local, 0, sizeof(local)); + memset(&remote, 0, sizeof(remote)); + + addrs.d.size_subflow_data = sizeof(struct mptcp_subflow_data); + addrs.d.size_user = sizeof(struct mptcp_subflow_addrs); + olen = sizeof(addrs); + + ret = getsockopt(fd, SOL_MPTCP, MPTCP_SUBFLOW_ADDRS, &addrs, &olen); + if (ret < 0) + die_perror("getsockopt MPTCP_SUBFLOW_ADDRS"); + + assert(olen <= sizeof(addrs)); + assert(addrs.d.size_kernel > 0); + assert(addrs.d.size_user == + MIN(addrs.d.size_kernel, sizeof(struct mptcp_subflow_addrs))); + assert(addrs.d.num_subflows == 1); + + assert(olen > (socklen_t)sizeof(struct mptcp_subflow_data)); + olen -= sizeof(struct mptcp_subflow_data); + assert(olen == addrs.d.size_user); + + llen = sizeof(local); + ret = getsockname(fd, (struct sockaddr *)&local, &llen); + if (ret < 0) + die_perror("getsockname"); + rlen = sizeof(remote); + ret = getpeername(fd, (struct sockaddr *)&remote, &rlen); + if (ret < 0) + die_perror("getpeername"); + + assert(rlen > 0); + assert(rlen == llen); + + assert(remote.ss_family == local.ss_family); + + assert(memcmp(&local, &addrs.addr[0].ss_local, sizeof(local)) == 0); + assert(memcmp(&remote, &addrs.addr[0].ss_remote, sizeof(remote)) == 0); + s->addrs = addrs.addr[0]; + + memset(&addrs, 0, sizeof(addrs)); + + addrs.d.size_subflow_data = sizeof(struct mptcp_subflow_data); + addrs.d.size_user = sizeof(sa_family_t); + olen = sizeof(addrs.d) + sizeof(sa_family_t); + + ret = getsockopt(fd, SOL_MPTCP, MPTCP_SUBFLOW_ADDRS, &addrs, &olen); + assert(ret == 0); + assert(olen == sizeof(addrs.d) + sizeof(sa_family_t)); + + assert(addrs.addr[0].sa_family == pf); + assert(addrs.addr[0].sa_family == local.ss_family); + + assert(memcmp(&local, &addrs.addr[0].ss_local, sizeof(local)) != 0); + assert(memcmp(&remote, &addrs.addr[0].ss_remote, sizeof(remote)) != 0); + + do_getsockopt_bogus_sf_data(fd, MPTCP_SUBFLOW_ADDRS); +} + +static void do_getsockopt_mptcp_full_info(struct so_state *s, int fd) +{ + size_t data_size = sizeof(struct mptcp_full_info); + struct mptcp_subflow_info sfinfo[2]; + struct tcp_info tcp_info[2]; + struct mptcp_full_info mfi; + socklen_t olen; + int ret; + + memset(&mfi, 0, data_size); + memset(tcp_info, 0, sizeof(tcp_info)); + memset(sfinfo, 0, sizeof(sfinfo)); + + mfi.size_tcpinfo_user = sizeof(struct tcp_info); + mfi.size_sfinfo_user = sizeof(struct mptcp_subflow_info); + mfi.size_arrays_user = 2; + mfi.subflow_info = (unsigned long)&sfinfo[0]; + mfi.tcp_info = (unsigned long)&tcp_info[0]; + olen = data_size; + + ret = getsockopt(fd, SOL_MPTCP, MPTCP_FULL_INFO, &mfi, &olen); + if (ret < 0) { + if (errno == EOPNOTSUPP) { + perror("MPTCP_FULL_INFO test skipped"); + return; + } + xerror("getsockopt MPTCP_FULL_INFO"); + } + + assert(olen <= data_size); + assert(mfi.size_tcpinfo_kernel > 0); + assert(mfi.size_tcpinfo_user == + MIN(mfi.size_tcpinfo_kernel, sizeof(struct tcp_info))); + assert(mfi.size_sfinfo_kernel > 0); + assert(mfi.size_sfinfo_user == + MIN(mfi.size_sfinfo_kernel, sizeof(struct mptcp_subflow_info))); + assert(mfi.num_subflows == 1); + + /* Tolerate future extension to mptcp_info struct and running newer + * test on top of older kernel. + * Anyway any kernel supporting MPTCP_FULL_INFO must at least include + * the following in mptcp_info. + */ + assert(olen > (socklen_t)__builtin_offsetof(struct mptcp_full_info, tcp_info)); + assert(mfi.mptcp_info.mptcpi_subflows == 0); + assert(mfi.mptcp_info.mptcpi_bytes_sent == s->last_sample.mptcpi_bytes_sent); + assert(mfi.mptcp_info.mptcpi_bytes_received == s->last_sample.mptcpi_bytes_received); + + assert(sfinfo[0].id == 1); + assert(tcp_info[0].tcpi_bytes_sent == s->tcp_info.tcpi_bytes_sent); + assert(tcp_info[0].tcpi_bytes_received == s->tcp_info.tcpi_bytes_received); + assert(!memcmp(&sfinfo->addrs, &s->addrs, sizeof(struct mptcp_subflow_addrs))); +} + +static void do_getsockopts(struct so_state *s, int fd, size_t r, size_t w) +{ + do_getsockopt_mptcp_info(s, fd, w); + + do_getsockopt_tcp_info(s, fd, r, w); + + do_getsockopt_subflow_addrs(s, fd); + + if (r) + do_getsockopt_mptcp_full_info(s, fd); +} + +static void connect_one_server(int fd, int pipefd) +{ + char buf[4096], buf2[4096]; + size_t len, i, total; + struct so_state s; + bool eof = false; + ssize_t ret; + + memset(&s, 0, sizeof(s)); + + len = rand() % (sizeof(buf) - 1); + + if (len < 128) + len = 128; + + for (i = 0; i < len ; i++) { + buf[i] = rand() % 26; + buf[i] += 'A'; + } + + buf[i] = '\n'; + + do_getsockopts(&s, fd, 0, 0); + + /* un-block server */ + ret = read(pipefd, buf2, 4); + assert(ret == 4); + close(pipefd); + + assert(strncmp(buf2, "xmit", 4) == 0); + + ret = write(fd, buf, len); + if (ret < 0) + die_perror("write"); + + if (ret != (ssize_t)len) + xerror("short write"); + + total = 0; + do { + ret = read(fd, buf2 + total, sizeof(buf2) - total); + if (ret < 0) + die_perror("read"); + if (ret == 0) { + eof = true; + break; + } + + total += ret; + } while (total < len); + + if (total != len) + xerror("total %lu, len %lu eof %d\n", total, len, eof); + + if (memcmp(buf, buf2, len)) + xerror("data corruption"); + + if (s.tcpi_rcv_delta) + assert(s.tcpi_rcv_delta <= total); + + do_getsockopts(&s, fd, ret, ret); + + if (eof) + total += 1; /* sequence advances due to FIN */ + + assert(s.mptcpi_rcv_delta == (uint64_t)total); + close(fd); +} + +static void process_one_client(int fd, int pipefd) +{ + ssize_t ret, ret2, ret3; + struct so_state s; + char buf[4096]; + + memset(&s, 0, sizeof(s)); + do_getsockopts(&s, fd, 0, 0); + + ret = write(pipefd, "xmit", 4); + assert(ret == 4); + + ret = read(fd, buf, sizeof(buf)); + if (ret < 0) + die_perror("read"); + + assert(s.mptcpi_rcv_delta <= (uint64_t)ret); + + if (s.tcpi_rcv_delta) + assert(s.tcpi_rcv_delta == (uint64_t)ret); + + ret2 = write(fd, buf, ret); + if (ret2 < 0) + die_perror("write"); + + /* wait for hangup */ + ret3 = read(fd, buf, 1); + if (ret3 != 0) + xerror("expected EOF, got %lu", ret3); + + do_getsockopts(&s, fd, ret, ret2); + if (s.mptcpi_rcv_delta != (uint64_t)ret + 1) + xerror("mptcpi_rcv_delta %" PRIu64 ", expect %" PRIu64, s.mptcpi_rcv_delta, ret + 1, s.mptcpi_rcv_delta - ret); + + /* be nice when running on top of older kernel */ + if (s.pkt_stats_avail) { + if (s.last_sample.mptcpi_bytes_sent != ret2) + xerror("mptcpi_bytes_sent %" PRIu64 ", expect %" PRIu64, + s.last_sample.mptcpi_bytes_sent, ret2, + s.last_sample.mptcpi_bytes_sent - ret2); + if (s.last_sample.mptcpi_bytes_received != ret) + xerror("mptcpi_bytes_received %" PRIu64 ", expect %" PRIu64, + s.last_sample.mptcpi_bytes_received, ret, + s.last_sample.mptcpi_bytes_received - ret); + if (s.last_sample.mptcpi_bytes_acked != ret) + xerror("mptcpi_bytes_acked %" PRIu64 ", expect %" PRIu64, + s.last_sample.mptcpi_bytes_acked, ret2, + s.last_sample.mptcpi_bytes_acked - ret2); + } + + close(fd); +} + +static int xaccept(int s) +{ + int fd = accept(s, NULL, 0); + + if (fd < 0) + die_perror("accept"); + + return fd; +} + +static int server(int pipefd) +{ + int fd = -1, r; + + switch (pf) { + case AF_INET: + fd = sock_listen_mptcp("127.0.0.1", "15432"); + break; + case AF_INET6: + fd = sock_listen_mptcp("::1", "15432"); + break; + default: + xerror("Unknown pf %d\n", pf); + break; + } + + r = write(pipefd, "conn", 4); + assert(r == 4); + + alarm(15); + r = xaccept(fd); + + process_one_client(r, pipefd); + + return 0; +} + +static void test_ip_tos_sockopt(int fd) +{ + uint8_t tos_in, tos_out; + socklen_t s; + int r; + + tos_in = rand() & 0xfc; + r = setsockopt(fd, SOL_IP, IP_TOS, &tos_in, sizeof(tos_out)); + if (r != 0) + die_perror("setsockopt IP_TOS"); + + tos_out = 0; + s = sizeof(tos_out); + r = getsockopt(fd, SOL_IP, IP_TOS, &tos_out, &s); + if (r != 0) + die_perror("getsockopt IP_TOS"); + + if (tos_in != tos_out) + xerror("tos %x != %x socklen_t %d\n", tos_in, tos_out, s); + + if (s != 1) + xerror("tos should be 1 byte"); + + s = 0; + r = getsockopt(fd, SOL_IP, IP_TOS, &tos_out, &s); + if (r != 0) + die_perror("getsockopt IP_TOS 0"); + if (s != 0) + xerror("expect socklen_t == 0"); + + s = -1; + r = getsockopt(fd, SOL_IP, IP_TOS, &tos_out, &s); + if (r != -1 && errno != EINVAL) + die_perror("getsockopt IP_TOS did not indicate -EINVAL"); + if (s != -1) + xerror("expect socklen_t == -1"); +} + +static int client(int pipefd) +{ + int fd = -1; + + alarm(15); + + switch (pf) { + case AF_INET: + fd = sock_connect_mptcp("127.0.0.1", "15432", IPPROTO_MPTCP); + break; + case AF_INET6: + fd = sock_connect_mptcp("::1", "15432", IPPROTO_MPTCP); + break; + default: + xerror("Unknown pf %d\n", pf); + } + + test_ip_tos_sockopt(fd); + + connect_one_server(fd, pipefd); + + return 0; +} + +static pid_t xfork(void) +{ + pid_t p = fork(); + + if (p < 0) + die_perror("fork"); + + return p; +} + +static int rcheck(int wstatus, const char *what) +{ + if (WIFEXITED(wstatus)) { + if (WEXITSTATUS(wstatus) == 0) + return 0; + fprintf(stderr, "%s exited, status=%d\n", what, WEXITSTATUS(wstatus)); + return WEXITSTATUS(wstatus); + } else if (WIFSIGNALED(wstatus)) { + xerror("%s killed by signal %d\n", what, WTERMSIG(wstatus)); + } else if (WIFSTOPPED(wstatus)) { + xerror("%s stopped by signal %d\n", what, WSTOPSIG(wstatus)); + } + + return 111; +} + +static void init_rng(void) +{ + int fd = open("/dev/urandom", O_RDONLY); + + if (fd >= 0) { + unsigned int foo; + ssize_t ret; + + /* can't fail */ + ret = read(fd, &foo, sizeof(foo)); + assert(ret == sizeof(foo)); + + close(fd); + srand(foo); + } else { + srand(time(NULL)); + } +} + +int main(int argc, char *argv[]) +{ + int e1, e2, wstatus; + pid_t s, c, ret; + int pipefds[2]; + + parse_opts(argc, argv); + + init_rng(); + + e1 = pipe(pipefds); + if (e1 < 0) + die_perror("pipe"); + + s = xfork(); + if (s == 0) + return server(pipefds[1]); + + close(pipefds[1]); + + /* wait until server bound a socket */ + e1 = read(pipefds[0], &e1, 4); + assert(e1 == 4); + + c = xfork(); + if (c == 0) + return client(pipefds[0]); + + close(pipefds[0]); + + ret = waitpid(s, &wstatus, 0); + if (ret == -1) + die_perror("waitpid"); + e1 = rcheck(wstatus, "server"); + ret = waitpid(c, &wstatus, 0); + if (ret == -1) + die_perror("waitpid"); + e2 = rcheck(wstatus, "client"); + + return e1 ? e1 : e2; +} |