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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-27 10:05:51 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-27 10:05:51 +0000 |
commit | 5d1646d90e1f2cceb9f0828f4b28318cd0ec7744 (patch) | |
tree | a94efe259b9009378be6d90eb30d2b019d95c194 /tools/testing/selftests/net/ip_defrag.c | |
parent | Initial commit. (diff) | |
download | linux-5d1646d90e1f2cceb9f0828f4b28318cd0ec7744.tar.xz linux-5d1646d90e1f2cceb9f0828f4b28318cd0ec7744.zip |
Adding upstream version 5.10.209.upstream/5.10.209upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'tools/testing/selftests/net/ip_defrag.c')
-rw-r--r-- | tools/testing/selftests/net/ip_defrag.c | 472 |
1 files changed, 472 insertions, 0 deletions
diff --git a/tools/testing/selftests/net/ip_defrag.c b/tools/testing/selftests/net/ip_defrag.c new file mode 100644 index 000000000..f9ed749fd --- /dev/null +++ b/tools/testing/selftests/net/ip_defrag.c @@ -0,0 +1,472 @@ +// SPDX-License-Identifier: GPL-2.0 + +#define _GNU_SOURCE + +#include <arpa/inet.h> +#include <errno.h> +#include <error.h> +#include <linux/in.h> +#include <netinet/ip.h> +#include <netinet/ip6.h> +#include <netinet/udp.h> +#include <stdbool.h> +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <time.h> +#include <unistd.h> + +static bool cfg_do_ipv4; +static bool cfg_do_ipv6; +static bool cfg_verbose; +static bool cfg_overlap; +static bool cfg_permissive; +static unsigned short cfg_port = 9000; + +const struct in_addr addr4 = { .s_addr = __constant_htonl(INADDR_LOOPBACK + 2) }; +const struct in6_addr addr6 = IN6ADDR_LOOPBACK_INIT; + +#define IP4_HLEN (sizeof(struct iphdr)) +#define IP6_HLEN (sizeof(struct ip6_hdr)) +#define UDP_HLEN (sizeof(struct udphdr)) + +/* IPv6 fragment header lenth. */ +#define FRAG_HLEN 8 + +static int payload_len; +static int max_frag_len; + +#define MSG_LEN_MAX 10000 /* Max UDP payload length. */ + +#define IP4_MF (1u << 13) /* IPv4 MF flag. */ +#define IP6_MF (1) /* IPv6 MF flag. */ + +#define CSUM_MANGLED_0 (0xffff) + +static uint8_t udp_payload[MSG_LEN_MAX]; +static uint8_t ip_frame[IP_MAXPACKET]; +static uint32_t ip_id = 0xabcd; +static int msg_counter; +static int frag_counter; +static unsigned int seed; + +/* Receive a UDP packet. Validate it matches udp_payload. */ +static void recv_validate_udp(int fd_udp) +{ + ssize_t ret; + static uint8_t recv_buff[MSG_LEN_MAX]; + + ret = recv(fd_udp, recv_buff, payload_len, 0); + msg_counter++; + + if (cfg_overlap) { + if (ret == -1 && (errno == ETIMEDOUT || errno == EAGAIN)) + return; /* OK */ + if (!cfg_permissive) { + if (ret != -1) + error(1, 0, "recv: expected timeout; got %d", + (int)ret); + error(1, errno, "recv: expected timeout: %d", errno); + } + } + + if (ret == -1) + error(1, errno, "recv: payload_len = %d max_frag_len = %d", + payload_len, max_frag_len); + if (ret != payload_len) + error(1, 0, "recv: wrong size: %d vs %d", (int)ret, payload_len); + if (memcmp(udp_payload, recv_buff, payload_len)) + error(1, 0, "recv: wrong data"); +} + +static uint32_t raw_checksum(uint8_t *buf, int len, uint32_t sum) +{ + int i; + + for (i = 0; i < (len & ~1U); i += 2) { + sum += (u_int16_t)ntohs(*((u_int16_t *)(buf + i))); + if (sum > 0xffff) + sum -= 0xffff; + } + + if (i < len) { + sum += buf[i] << 8; + if (sum > 0xffff) + sum -= 0xffff; + } + + return sum; +} + +static uint16_t udp_checksum(struct ip *iphdr, struct udphdr *udphdr) +{ + uint32_t sum = 0; + uint16_t res; + + sum = raw_checksum((uint8_t *)&iphdr->ip_src, 2 * sizeof(iphdr->ip_src), + IPPROTO_UDP + (uint32_t)(UDP_HLEN + payload_len)); + sum = raw_checksum((uint8_t *)udphdr, UDP_HLEN, sum); + sum = raw_checksum((uint8_t *)udp_payload, payload_len, sum); + res = 0xffff & ~sum; + if (res) + return htons(res); + else + return CSUM_MANGLED_0; +} + +static uint16_t udp6_checksum(struct ip6_hdr *iphdr, struct udphdr *udphdr) +{ + uint32_t sum = 0; + uint16_t res; + + sum = raw_checksum((uint8_t *)&iphdr->ip6_src, 2 * sizeof(iphdr->ip6_src), + IPPROTO_UDP); + sum = raw_checksum((uint8_t *)&udphdr->len, sizeof(udphdr->len), sum); + sum = raw_checksum((uint8_t *)udphdr, UDP_HLEN, sum); + sum = raw_checksum((uint8_t *)udp_payload, payload_len, sum); + res = 0xffff & ~sum; + if (res) + return htons(res); + else + return CSUM_MANGLED_0; +} + +static void send_fragment(int fd_raw, struct sockaddr *addr, socklen_t alen, + int offset, bool ipv6) +{ + int frag_len; + int res; + int payload_offset = offset > 0 ? offset - UDP_HLEN : 0; + uint8_t *frag_start = ipv6 ? ip_frame + IP6_HLEN + FRAG_HLEN : + ip_frame + IP4_HLEN; + + if (offset == 0) { + struct udphdr udphdr; + udphdr.source = htons(cfg_port + 1); + udphdr.dest = htons(cfg_port); + udphdr.len = htons(UDP_HLEN + payload_len); + udphdr.check = 0; + if (ipv6) + udphdr.check = udp6_checksum((struct ip6_hdr *)ip_frame, &udphdr); + else + udphdr.check = udp_checksum((struct ip *)ip_frame, &udphdr); + memcpy(frag_start, &udphdr, UDP_HLEN); + } + + if (ipv6) { + struct ip6_hdr *ip6hdr = (struct ip6_hdr *)ip_frame; + struct ip6_frag *fraghdr = (struct ip6_frag *)(ip_frame + IP6_HLEN); + if (payload_len - payload_offset <= max_frag_len && offset > 0) { + /* This is the last fragment. */ + frag_len = FRAG_HLEN + payload_len - payload_offset; + fraghdr->ip6f_offlg = htons(offset); + } else { + frag_len = FRAG_HLEN + max_frag_len; + fraghdr->ip6f_offlg = htons(offset | IP6_MF); + } + ip6hdr->ip6_plen = htons(frag_len); + if (offset == 0) + memcpy(frag_start + UDP_HLEN, udp_payload, + frag_len - FRAG_HLEN - UDP_HLEN); + else + memcpy(frag_start, udp_payload + payload_offset, + frag_len - FRAG_HLEN); + frag_len += IP6_HLEN; + } else { + struct ip *iphdr = (struct ip *)ip_frame; + if (payload_len - payload_offset <= max_frag_len && offset > 0) { + /* This is the last fragment. */ + frag_len = IP4_HLEN + payload_len - payload_offset; + iphdr->ip_off = htons(offset / 8); + } else { + frag_len = IP4_HLEN + max_frag_len; + iphdr->ip_off = htons(offset / 8 | IP4_MF); + } + iphdr->ip_len = htons(frag_len); + if (offset == 0) + memcpy(frag_start + UDP_HLEN, udp_payload, + frag_len - IP4_HLEN - UDP_HLEN); + else + memcpy(frag_start, udp_payload + payload_offset, + frag_len - IP4_HLEN); + } + + res = sendto(fd_raw, ip_frame, frag_len, 0, addr, alen); + if (res < 0 && errno != EPERM) + error(1, errno, "send_fragment"); + if (res >= 0 && res != frag_len) + error(1, 0, "send_fragment: %d vs %d", res, frag_len); + + frag_counter++; +} + +static void send_udp_frags(int fd_raw, struct sockaddr *addr, + socklen_t alen, bool ipv6) +{ + struct ip *iphdr = (struct ip *)ip_frame; + struct ip6_hdr *ip6hdr = (struct ip6_hdr *)ip_frame; + int res; + int offset; + int frag_len; + + /* Send the UDP datagram using raw IP fragments: the 0th fragment + * has the UDP header; other fragments are pieces of udp_payload + * split in chunks of frag_len size. + * + * Odd fragments (1st, 3rd, 5th, etc.) are sent out first, then + * even fragments (0th, 2nd, etc.) are sent out. + */ + if (ipv6) { + struct ip6_frag *fraghdr = (struct ip6_frag *)(ip_frame + IP6_HLEN); + ((struct sockaddr_in6 *)addr)->sin6_port = 0; + memset(ip6hdr, 0, sizeof(*ip6hdr)); + ip6hdr->ip6_flow = htonl(6<<28); /* Version. */ + ip6hdr->ip6_nxt = IPPROTO_FRAGMENT; + ip6hdr->ip6_hops = 255; + ip6hdr->ip6_src = addr6; + ip6hdr->ip6_dst = addr6; + fraghdr->ip6f_nxt = IPPROTO_UDP; + fraghdr->ip6f_reserved = 0; + fraghdr->ip6f_ident = htonl(ip_id++); + } else { + memset(iphdr, 0, sizeof(*iphdr)); + iphdr->ip_hl = 5; + iphdr->ip_v = 4; + iphdr->ip_tos = 0; + iphdr->ip_id = htons(ip_id++); + iphdr->ip_ttl = 0x40; + iphdr->ip_p = IPPROTO_UDP; + iphdr->ip_src.s_addr = htonl(INADDR_LOOPBACK); + iphdr->ip_dst = addr4; + iphdr->ip_sum = 0; + } + + /* Occasionally test in-order fragments. */ + if (!cfg_overlap && (rand() % 100 < 15)) { + offset = 0; + while (offset < (UDP_HLEN + payload_len)) { + send_fragment(fd_raw, addr, alen, offset, ipv6); + offset += max_frag_len; + } + return; + } + + /* Occasionally test IPv4 "runs" (see net/ipv4/ip_fragment.c) */ + if (!cfg_overlap && (rand() % 100 < 20) && + (payload_len > 9 * max_frag_len)) { + offset = 6 * max_frag_len; + while (offset < (UDP_HLEN + payload_len)) { + send_fragment(fd_raw, addr, alen, offset, ipv6); + offset += max_frag_len; + } + offset = 3 * max_frag_len; + while (offset < 6 * max_frag_len) { + send_fragment(fd_raw, addr, alen, offset, ipv6); + offset += max_frag_len; + } + offset = 0; + while (offset < 3 * max_frag_len) { + send_fragment(fd_raw, addr, alen, offset, ipv6); + offset += max_frag_len; + } + return; + } + + /* Odd fragments. */ + offset = max_frag_len; + while (offset < (UDP_HLEN + payload_len)) { + send_fragment(fd_raw, addr, alen, offset, ipv6); + /* IPv4 ignores duplicates, so randomly send a duplicate. */ + if (rand() % 100 == 1) + send_fragment(fd_raw, addr, alen, offset, ipv6); + offset += 2 * max_frag_len; + } + + if (cfg_overlap) { + /* Send an extra random fragment. + * + * Duplicates and some fragments completely inside + * previously sent fragments are dropped/ignored. So + * random offset and frag_len can result in a dropped + * fragment instead of a dropped queue/packet. Thus we + * hard-code offset and frag_len. + */ + if (max_frag_len * 4 < payload_len || max_frag_len < 16) { + /* not enough payload for random offset and frag_len. */ + offset = 8; + frag_len = UDP_HLEN + max_frag_len; + } else { + offset = rand() % (payload_len / 2); + frag_len = 2 * max_frag_len + 1 + rand() % 256; + } + if (ipv6) { + struct ip6_frag *fraghdr = (struct ip6_frag *)(ip_frame + IP6_HLEN); + /* sendto() returns EINVAL if offset + frag_len is too small. */ + /* In IPv6 if !!(frag_len % 8), the fragment is dropped. */ + frag_len &= ~0x7; + fraghdr->ip6f_offlg = htons(offset / 8 | IP6_MF); + ip6hdr->ip6_plen = htons(frag_len); + frag_len += IP6_HLEN; + } else { + frag_len += IP4_HLEN; + iphdr->ip_off = htons(offset / 8 | IP4_MF); + iphdr->ip_len = htons(frag_len); + } + res = sendto(fd_raw, ip_frame, frag_len, 0, addr, alen); + if (res < 0 && errno != EPERM) + error(1, errno, "sendto overlap: %d", frag_len); + if (res >= 0 && res != frag_len) + error(1, 0, "sendto overlap: %d vs %d", (int)res, frag_len); + frag_counter++; + } + + /* Event fragments. */ + offset = 0; + while (offset < (UDP_HLEN + payload_len)) { + send_fragment(fd_raw, addr, alen, offset, ipv6); + /* IPv4 ignores duplicates, so randomly send a duplicate. */ + if (rand() % 100 == 1) + send_fragment(fd_raw, addr, alen, offset, ipv6); + offset += 2 * max_frag_len; + } +} + +static void run_test(struct sockaddr *addr, socklen_t alen, bool ipv6) +{ + int fd_tx_raw, fd_rx_udp; + /* Frag queue timeout is set to one second in the calling script; + * socket timeout should be just a bit longer to avoid tests interfering + * with each other. + */ + struct timeval tv = { .tv_sec = 1, .tv_usec = 10 }; + int idx; + int min_frag_len = 8; + + /* Initialize the payload. */ + for (idx = 0; idx < MSG_LEN_MAX; ++idx) + udp_payload[idx] = idx % 256; + + /* Open sockets. */ + fd_tx_raw = socket(addr->sa_family, SOCK_RAW, IPPROTO_RAW); + if (fd_tx_raw == -1) + error(1, errno, "socket tx_raw"); + + fd_rx_udp = socket(addr->sa_family, SOCK_DGRAM, 0); + if (fd_rx_udp == -1) + error(1, errno, "socket rx_udp"); + if (bind(fd_rx_udp, addr, alen)) + error(1, errno, "bind"); + /* Fail fast. */ + if (setsockopt(fd_rx_udp, SOL_SOCKET, SO_RCVTIMEO, &tv, sizeof(tv))) + error(1, errno, "setsockopt rcv timeout"); + + for (payload_len = min_frag_len; payload_len < MSG_LEN_MAX; + payload_len += (rand() % 4096)) { + if (cfg_verbose) + printf("payload_len: %d\n", payload_len); + + if (cfg_overlap) { + /* With overlaps, one send/receive pair below takes + * at least one second (== timeout) to run, so there + * is not enough test time to run a nested loop: + * the full overlap test takes 20-30 seconds. + */ + max_frag_len = min_frag_len + + rand() % (1500 - FRAG_HLEN - min_frag_len); + send_udp_frags(fd_tx_raw, addr, alen, ipv6); + recv_validate_udp(fd_rx_udp); + } else { + /* Without overlaps, each packet reassembly (== one + * send/receive pair below) takes very little time to + * run, so we can easily afford more thourough testing + * with a nested loop: the full non-overlap test takes + * less than one second). + */ + max_frag_len = min_frag_len; + do { + send_udp_frags(fd_tx_raw, addr, alen, ipv6); + recv_validate_udp(fd_rx_udp); + max_frag_len += 8 * (rand() % 8); + } while (max_frag_len < (1500 - FRAG_HLEN) && + max_frag_len <= payload_len); + } + } + + /* Cleanup. */ + if (close(fd_tx_raw)) + error(1, errno, "close tx_raw"); + if (close(fd_rx_udp)) + error(1, errno, "close rx_udp"); + + if (cfg_verbose) + printf("processed %d messages, %d fragments\n", + msg_counter, frag_counter); + + fprintf(stderr, "PASS\n"); +} + + +static void run_test_v4(void) +{ + struct sockaddr_in addr = {0}; + + addr.sin_family = AF_INET; + addr.sin_port = htons(cfg_port); + addr.sin_addr = addr4; + + run_test((void *)&addr, sizeof(addr), false /* !ipv6 */); +} + +static void run_test_v6(void) +{ + struct sockaddr_in6 addr = {0}; + + addr.sin6_family = AF_INET6; + addr.sin6_port = htons(cfg_port); + addr.sin6_addr = addr6; + + run_test((void *)&addr, sizeof(addr), true /* ipv6 */); +} + +static void parse_opts(int argc, char **argv) +{ + int c; + + while ((c = getopt(argc, argv, "46opv")) != -1) { + switch (c) { + case '4': + cfg_do_ipv4 = true; + break; + case '6': + cfg_do_ipv6 = true; + break; + case 'o': + cfg_overlap = true; + break; + case 'p': + cfg_permissive = true; + break; + case 'v': + cfg_verbose = true; + break; + default: + error(1, 0, "%s: parse error", argv[0]); + } + } +} + +int main(int argc, char **argv) +{ + parse_opts(argc, argv); + seed = time(NULL); + srand(seed); + /* Print the seed to track/reproduce potential failures. */ + printf("seed = %d\n", seed); + + if (cfg_do_ipv4) + run_test_v4(); + if (cfg_do_ipv6) + run_test_v6(); + + return 0; +} |