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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
commit2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch)
tree848558de17fb3008cdf4d861b01ac7781903ce39 /tools/testing/selftests/net/ip_defrag.c
parentInitial commit. (diff)
downloadlinux-2c3c1048746a4622d8c89a29670120dc8fab93c4.tar.xz
linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.zip
Adding upstream version 6.1.76.upstream/6.1.76upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to '')
-rw-r--r--tools/testing/selftests/net/ip_defrag.c472
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;
+}