diff options
Diffstat (limited to 'doc/platform-requirements/tcp-close-rst.c')
| -rw-r--r-- | doc/platform-requirements/tcp-close-rst.c | 204 |
1 files changed, 204 insertions, 0 deletions
diff --git a/doc/platform-requirements/tcp-close-rst.c b/doc/platform-requirements/tcp-close-rst.c new file mode 100644 index 0000000..0e508f6 --- /dev/null +++ b/doc/platform-requirements/tcp-close-rst.c @@ -0,0 +1,204 @@ +// SPDX-License-Identifier: GPL-2.0-or-later + +/* tcp-close-rst.c + * + * Check what operations on a TCP socket will trigger an RST. + * + * Copyright Red Hat + * Author: David Gibson <david@gibson.dropbear.id.au> + */ + +#include <arpa/inet.h> +#include <errno.h> +#include <fcntl.h> +#include <net/if.h> +#include <netinet/in.h> +#include <stdbool.h> +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <sys/socket.h> +#include <unistd.h> + +#include "common.h" + +#define DSTPORT 13258U + +#define SRCADDR(n) \ + (0x7f000000U | (n) << 16U | (n) << 8U | 0x1U) + +#define BASENUM 100 + +/* 127.0.0.1:DSTPORT */ +static const struct sockaddr_in lo_dst = SOCKADDR_INIT(INADDR_LOOPBACK, DSTPORT); + +#define LINGER 0x01U +#define SHUT_CLIENT 0x02U +#define SHUT_SERVER 0x04U + +#define NUM_OPTIONS (SHUT_SERVER << 1U) + +static void client_close(int sl, unsigned flags) +{ + struct sockaddr_in src = SOCKADDR_INIT(SRCADDR(flags), 0); + struct linger linger0 = { + .l_onoff = 1, + .l_linger = 0, + }; + int sockerr, sc, sa; + socklen_t errlen = sizeof(sockerr); + + printf("Client close %u:%s%s%s\n", flags, + flags & LINGER ? " LINGER" : "", + flags & SHUT_CLIENT ? " SHUT_CLIENT" : "", + flags & SHUT_SERVER ? " SHUT_SERVER" : ""); + + sc = socket(PF_INET, SOCK_STREAM, IPPROTO_TCP); + if (sc < 0) + die("socket() for connect(): %s\n", strerror(errno)); + + if (bind(sc, (struct sockaddr *)&src, sizeof(src)) < 0) + die("bind() for connect: %s\n", strerror(errno)); + + if (connect(sc, (struct sockaddr *)&lo_dst, sizeof(lo_dst)) < 0) + die("connect(): %s\n", strerror(errno)); + + /* cppcheck-suppress [android-cloexec-accept,unmatchedSuppression] */ + sa = accept(sl, NULL, NULL); + if (sa < 0) + die("accept(): %s\n", strerror(errno)); + + if (flags & SHUT_SERVER) + if (shutdown(sa, SHUT_WR) < 0) + die("shutdown() server: %s\n", strerror(errno)); + + if (flags & SHUT_CLIENT) + if (shutdown(sc, SHUT_WR) < 0) + die("shutdown() client: %s\n", strerror(errno)); + + if (flags & LINGER) + if (setsockopt(sc, SOL_SOCKET, SO_LINGER, + &linger0, sizeof(linger0)) < 0) + die("SO_LINGER: %s\n", strerror(errno)); + + close(sc); + + if (getsockopt(sa, SOL_SOCKET, SO_ERROR, &sockerr, &errlen) < 0) + die("SO_ERROR: %s\n", strerror(errno)); + + if (errlen != sizeof(sockerr)) + die("SO_ERROR: bad option length\n"); + + printf("Server error: %s\n", strerror(sockerr)); + + if (flags & LINGER) { + if (!(flags & SHUT_SERVER) || !(flags & SHUT_CLIENT)) { + if (sockerr == 0) + die("No error after abrupt close(), no RST?\n"); + } else { + if (sockerr != 0) + die("Error after full shutdown, bogus RST?\n"); + } + } + + close(sa); +} + +static void server_close(int sl, unsigned flags) +{ + struct sockaddr_in src = SOCKADDR_INIT(SRCADDR(flags), 0); + struct linger linger0 = { + .l_onoff = 1, + .l_linger = 0, + }; + int sockerr, sc, sa; + socklen_t errlen = sizeof(sockerr); + + printf("Server close %u:%s%s%s\n", flags, + flags & LINGER ? " LINGER" : "", + flags & SHUT_CLIENT ? " SHUT_CLIENT" : "", + flags & SHUT_SERVER ? " SHUT_SERVER" : ""); + + sc = socket(PF_INET, SOCK_STREAM, IPPROTO_TCP); + if (sc < 0) + die("socket() for connect(): %s\n", strerror(errno)); + + if (bind(sc, (struct sockaddr *)&src, sizeof(src)) < 0) + die("bind() for connect: %s\n", strerror(errno)); + + if (connect(sc, (struct sockaddr *)&lo_dst, sizeof(lo_dst)) < 0) + die("connect(): %s\n", strerror(errno)); + + /* cppcheck-suppress [android-cloexec-accept,unmatchedSuppression] */ + sa = accept(sl, NULL, NULL); + if (sa < 0) + die("accept(): %s\n", strerror(errno)); + + if (flags & SHUT_SERVER) + if (shutdown(sa, SHUT_WR) < 0) + die("shutdown() server: %s\n", strerror(errno)); + + if (flags & SHUT_CLIENT) + if (shutdown(sc, SHUT_WR) < 0) + die("shutdown() client: %s\n", strerror(errno)); + + if (flags & LINGER) + if (setsockopt(sa, SOL_SOCKET, SO_LINGER, + &linger0, sizeof(linger0)) < 0) + die("SO_LINGER: %s\n", strerror(errno)); + + close(sa); + + if (getsockopt(sc, SOL_SOCKET, SO_ERROR, &sockerr, &errlen) < 0) + die("SO_ERROR: %s\n", strerror(errno)); + + if (errlen != sizeof(sockerr)) + die("SO_ERROR: bad option length\n"); + + printf("Client error: %s\n", strerror(sockerr)); + + if (flags & LINGER) { + if (!(flags & SHUT_SERVER) || !(flags & SHUT_CLIENT)) { + if (sockerr == 0) + die("No error after abrupt close(), no RST?\n"); + } else { + if (sockerr != 0) + die("Error after full shutdown, bogus RST?\n"); + } + } + + close(sc); +} + +int main(int argc, char *argv[]) +{ + unsigned flags; + int y = 1; + int sl; + + (void)argc; + (void)argv; + + sl = socket(PF_INET, SOCK_STREAM, IPPROTO_TCP); + if (sl < 0) + die("socket() for listen: %s\n", strerror(errno)); + + if (setsockopt(sl, SOL_SOCKET, SO_REUSEADDR, &y, sizeof(y)) < 0) + die("SO_REUSEADDR for listen: %s\n", strerror(errno)); + + if (bind(sl, (struct sockaddr *)&lo_dst, sizeof(lo_dst)) < 0) + die("bind() for listen: %s\n", strerror(errno)); + + if (listen(sl, 1) < 0) + die("listen(): %s\n", strerror(errno)); + + printf("Listening on port %u\n", DSTPORT); + + for (flags = 0; flags < NUM_OPTIONS; flags++) { + client_close(sl, flags); + server_close(sl, flags); + } + + close(sl); + exit(0); +} |