selftests/net: add ipv6 tests to ip_defrag selftest

This patch adds ipv6 defragmentation tests to ip_defrag selftest,
to complement existing ipv4 tests.

Signed-off-by: Peter Oskolkov <posk@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/tools/testing/selftests/net/ip_defrag.c b/tools/testing/selftests/net/ip_defrag.c
index 55fdcdc..2366dc6 100644 (file)
--- a/tools/testing/selftests/net/ip_defrag.c
+++ b/tools/testing/selftests/net/ip_defrag.c
@@ -23,21 +23,28 @@ static bool         cfg_overlap;
 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))
 
-static int msg_len;
+/* IPv6 fragment header lenth. */
+#define FRAG_HLEN      8
+
+static int payload_len;
 static int max_frag_len;
 
 #define MSG_LEN_MAX    60000   /* 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 uint16_t ip_id = 0xabcd;
+static uint32_t ip_id = 0xabcd;
 static int msg_counter;
 static int frag_counter;
 static unsigned int seed;
@@ -48,25 +55,25 @@ 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, msg_len, 0);
+       ret = recv(fd_udp, recv_buff, payload_len, 0);
        msg_counter++;
 
        if (cfg_overlap) {
                if (ret != -1)
-                       error(1, 0, "recv: expected timeout; got %d; seed = %u",
-                               (int)ret, seed);
+                       error(1, 0, "recv: expected timeout; got %d",
+                               (int)ret);
                if (errno != ETIMEDOUT && errno != EAGAIN)
-                       error(1, errno, "recv: expected timeout: %d; seed = %u",
-                                errno, seed);
+                       error(1, errno, "recv: expected timeout: %d",
+                                errno);
                return;  /* OK */
        }
 
        if (ret == -1)
-               error(1, errno, "recv: msg_len = %d max_frag_len = %d",
-                       msg_len, max_frag_len);
-       if (ret != msg_len)
-               error(1, 0, "recv: wrong size: %d vs %d", (int)ret, msg_len);
-       if (memcmp(udp_payload, recv_buff, msg_len))
+               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");
 }
 
@@ -92,31 +99,95 @@ static uint32_t raw_checksum(uint8_t *buf, int len, uint32_t 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 + msg_len));
-       sum = raw_checksum((uint8_t *)udp_payload, msg_len, sum);
+                               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);
-       return htons(0xffff & ~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,
-                               struct ip *iphdr, int offset)
+                               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 (msg_len - offset <= max_frag_len) {
-               /* This is the last fragment. */
-               frag_len = IP4_HLEN + msg_len - offset;
-               iphdr->ip_off = htons((offset + UDP_HLEN) / 8);
+       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 {
-               frag_len = IP4_HLEN + max_frag_len;
-               iphdr->ip_off = htons((offset + UDP_HLEN) / 8 | IP4_MF);
+               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);
        }
-       iphdr->ip_len = htons(frag_len);
-       memcpy(ip_frame + IP4_HLEN, udp_payload + offset,
-                frag_len - IP4_HLEN);
 
        res = sendto(fd_raw, ip_frame, frag_len, 0, addr, alen);
        if (res < 0)
@@ -127,9 +198,11 @@ static void send_fragment(int fd_raw, struct sockaddr *addr, socklen_t alen,
        frag_counter++;
 }
 
-static void send_udp_frags_v4(int fd_raw, struct sockaddr *addr, socklen_t alen)
+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;
        struct udphdr udphdr;
        int res;
        int offset;
@@ -142,31 +215,55 @@ static void send_udp_frags_v4(int fd_raw, struct sockaddr *addr, socklen_t alen)
         * Odd fragments (1st, 3rd, 5th, etc.) are sent out first, then
         * even fragments (0th, 2nd, etc.) are sent out.
         */
-       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;
+       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;
+       }
 
        /* Odd fragments. */
-       offset = 0;
-       while (offset < msg_len) {
-               send_fragment(fd_raw, addr, alen, iphdr, offset);
+       offset = max_frag_len;
+       while (offset < (UDP_HLEN + payload_len)) {
+               send_fragment(fd_raw, addr, alen, offset, ipv6);
                offset += 2 * max_frag_len;
        }
 
        if (cfg_overlap) {
                /* Send an extra random fragment. */
-               offset = rand() % (UDP_HLEN + msg_len - 1);
+               offset = rand() % (UDP_HLEN + payload_len - 1);
                /* sendto() returns EINVAL if offset + frag_len is too small. */
-               frag_len = IP4_HLEN + UDP_HLEN + rand() % 256;
-               iphdr->ip_off = htons(offset / 8 | IP4_MF);
-               iphdr->ip_len = htons(frag_len);
+               if (ipv6) {
+                       struct ip6_frag *fraghdr = (struct ip6_frag *)(ip_frame + IP6_HLEN);
+                       frag_len = max_frag_len + rand() % 256;
+                       /* 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 + UDP_HLEN + rand() % 256;
+                       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)
                        error(1, errno, "sendto overlap");
@@ -175,48 +272,26 @@ static void send_udp_frags_v4(int fd_raw, struct sockaddr *addr, socklen_t alen)
                frag_counter++;
        }
 
-       /* Zeroth fragment (UDP header). */
-       frag_len = IP4_HLEN + UDP_HLEN;
-       iphdr->ip_len = htons(frag_len);
-       iphdr->ip_off = htons(IP4_MF);
-
-       udphdr.source = htons(cfg_port + 1);
-       udphdr.dest = htons(cfg_port);
-       udphdr.len = htons(UDP_HLEN + msg_len);
-       udphdr.check = 0;
-       udphdr.check = udp_checksum(iphdr, &udphdr);
-
-       memcpy(ip_frame + IP4_HLEN, &udphdr, UDP_HLEN);
-       res = sendto(fd_raw, ip_frame, frag_len, 0, addr, alen);
-       if (res < 0)
-               error(1, errno, "sendto UDP header");
-       if (res != frag_len)
-               error(1, 0, "sendto UDP header: %d vs %d", (int)res, frag_len);
-       frag_counter++;
-
-       /* Even fragments. */
-       offset = max_frag_len;
-       while (offset < msg_len) {
-               send_fragment(fd_raw, addr, alen, iphdr, offset);
+       /* Event fragments. */
+       offset = 0;
+       while (offset < (UDP_HLEN + payload_len)) {
+               send_fragment(fd_raw, addr, alen, offset, ipv6);
                offset += 2 * max_frag_len;
        }
 }
 
-static void run_test(struct sockaddr *addr, socklen_t alen)
+static void run_test(struct sockaddr *addr, socklen_t alen, bool ipv6)
 {
-       int fd_tx_udp, fd_tx_raw, fd_rx_udp;
+       int fd_tx_raw, fd_rx_udp;
        struct timeval tv = { .tv_sec = 0, .tv_usec = 10 * 1000 };
        int idx;
+       int min_frag_len = ipv6 ? 1280 : 8;
 
        /* Initialize the payload. */
        for (idx = 0; idx < MSG_LEN_MAX; ++idx)
                udp_payload[idx] = idx % 256;
 
        /* Open sockets. */
-       fd_tx_udp = socket(addr->sa_family, SOCK_DGRAM, 0);
-       if (fd_tx_udp == -1)
-               error(1, errno, "socket tx_udp");
-
        fd_tx_raw = socket(addr->sa_family, SOCK_RAW, IPPROTO_RAW);
        if (fd_tx_raw == -1)
                error(1, errno, "socket tx_raw");
@@ -230,22 +305,21 @@ static void run_test(struct sockaddr *addr, socklen_t alen)
        if (setsockopt(fd_rx_udp, SOL_SOCKET, SO_RCVTIMEO, &tv, sizeof(tv)))
                error(1, errno, "setsockopt rcv timeout");
 
-       for (msg_len = 1; msg_len < MSG_LEN_MAX; msg_len += (rand() % 4096)) {
+       for (payload_len = min_frag_len; payload_len < MSG_LEN_MAX;
+                       payload_len += (rand() % 4096)) {
                if (cfg_verbose)
-                       printf("msg_len: %d\n", msg_len);
-               max_frag_len = addr->sa_family == AF_INET ? 8 : 1280;
-               for (; max_frag_len < 1500 && max_frag_len <= msg_len;
-                               max_frag_len += 8) {
-                       send_udp_frags_v4(fd_tx_raw, addr, alen);
+                       printf("payload_len: %d\n", payload_len);
+               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_tx_udp))
-               error(1, errno, "close tx_udp");
        if (close(fd_rx_udp))
                error(1, errno, "close rx_udp");
 
@@ -265,13 +339,18 @@ static void run_test_v4(void)
        addr.sin_port = htons(cfg_port);
        addr.sin_addr = addr4;
 
-       run_test((void *)&addr, sizeof(addr));
+       run_test((void *)&addr, sizeof(addr), false /* !ipv6 */);
 }
 
 static void run_test_v6(void)
 {
-       fprintf(stderr, "NOT IMPL.\n");
-       exit(1);
+       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)
@@ -303,6 +382,8 @@ 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();

diff --git a/tools/testing/selftests/net/ip_defrag.sh b/tools/testing/selftests/net/ip_defrag.sh
index 78743ad..3a4042d 100755 (executable)
--- a/tools/testing/selftests/net/ip_defrag.sh
+++ b/tools/testing/selftests/net/ip_defrag.sh
@@ -6,23 +6,34 @@
 set +x
 set -e
 
-echo "ipv4 defrag"
+readonly NETNS="ns-$(mktemp -u XXXXXX)"
+
+setup() {
+       ip netns add "${NETNS}"
+       ip -netns "${NETNS}" link set lo up
+       ip netns exec "${NETNS}" sysctl -w net.ipv4.ipfrag_high_thresh=9000000 &> /dev/null
+       ip netns exec "${NETNS}" sysctl -w net.ipv4.ipfrag_low_thresh=7000000 &> /dev/null
+       ip netns exec "${NETNS}" sysctl -w net.ipv6.ip6frag_high_thresh=9000000 &> /dev/null
+       ip netns exec "${NETNS}" sysctl -w net.ipv6.ip6frag_low_thresh=7000000 &> /dev/null
+}
 
-run_v4() {
-sysctl -w net.ipv4.ipfrag_high_thresh=9000000 &> /dev/null
-sysctl -w net.ipv4.ipfrag_low_thresh=7000000 &> /dev/null
-./ip_defrag -4
+cleanup() {
+       ip netns del "${NETNS}"
 }
-export -f run_v4
 
-./in_netns.sh "run_v4"
+trap cleanup EXIT
+setup
+
+echo "ipv4 defrag"
+ip netns exec "${NETNS}" ./ip_defrag -4
+
 
 echo "ipv4 defrag with overlaps"
-run_v4o() {
-sysctl -w net.ipv4.ipfrag_high_thresh=9000000 &> /dev/null
-sysctl -w net.ipv4.ipfrag_low_thresh=7000000 &> /dev/null
-./ip_defrag -4o
-}
-export -f run_v4o
+ip netns exec "${NETNS}" ./ip_defrag -4o
+
+echo "ipv6 defrag"
+ip netns exec "${NETNS}" ./ip_defrag -6
+
+echo "ipv6 defrag with overlaps"
+ip netns exec "${NETNS}" ./ip_defrag -6o
 
-./in_netns.sh "run_v4o"