selftests/net: fix GRO coalesce test and add ext header coalesce tests

Currently there is no test which checks that IPv6 extension header packets
successfully coalesce. This commit adds a test, which verifies two IPv6
packets with HBH extension headers do coalesce, and another test which
checks that packets with different extension header data do not coalesce
in GRO.

I changed the receive socket filter to accept a packet with one extension
header. This change exposed a bug in the fragment test -- the old BPF did
not accept the fragment packet. I updated correct_num_packets in the
fragment test accordingly.

Signed-off-by: Richard Gobert <richardbgobert@gmail.com>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Link: https://lore.kernel.org/r/69282fed-2415-47e8-b3d3-34939ec3eb56@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

diff --git a/tools/testing/selftests/net/gro.c b/tools/testing/selftests/net/gro.c
index 30024d0ed37391712b0d7eb93794a5fc8fa4e814..353e1e867fbb2e8521a7d23913113de37a142c0f 100644 (file)
--- a/tools/testing/selftests/net/gro.c
+++ b/tools/testing/selftests/net/gro.c
@@ -71,6 +71,12 @@
 #define MAX_PAYLOAD (IP_MAXPACKET - sizeof(struct tcphdr) - sizeof(struct ipv6hdr))
 #define NUM_LARGE_PKT (MAX_PAYLOAD / MSS)
 #define MAX_HDR_LEN (ETH_HLEN + sizeof(struct ipv6hdr) + sizeof(struct tcphdr))
+#define MIN_EXTHDR_SIZE 8
+#define EXT_PAYLOAD_1 "\x00\x00\x00\x00\x00\x00"
+#define EXT_PAYLOAD_2 "\x11\x11\x11\x11\x11\x11"
+
+#define ipv6_optlen(p)  (((p)->hdrlen+1) << 3) /* calculate IPv6 extension header len */
+#define BUILD_BUG_ON(condition) ((void)sizeof(char[1 - 2*!!(condition)]))
 
 static const char *addr6_src = "fdaa::2";
 static const char *addr6_dst = "fdaa::1";
@@ -104,7 +110,7 @@ static void setup_sock_filter(int fd)
        const int dport_off = tcp_offset + offsetof(struct tcphdr, dest);
        const int ethproto_off = offsetof(struct ethhdr, h_proto);
        int optlen = 0;
-       int ipproto_off;
+       int ipproto_off, opt_ipproto_off;
        int next_off;
 
        if (proto == PF_INET)
@@ -116,14 +122,30 @@ static void setup_sock_filter(int fd)
        if (strcmp(testname, "ip") == 0) {
                if (proto == PF_INET)
                        optlen = sizeof(struct ip_timestamp);
-               else
-                       optlen = sizeof(struct ip6_frag);
+               else {
+                       BUILD_BUG_ON(sizeof(struct ip6_hbh) > MIN_EXTHDR_SIZE);
+                       BUILD_BUG_ON(sizeof(struct ip6_dest) > MIN_EXTHDR_SIZE);
+                       BUILD_BUG_ON(sizeof(struct ip6_frag) > MIN_EXTHDR_SIZE);
+
+                       /* same size for HBH and Fragment extension header types */
+                       optlen = MIN_EXTHDR_SIZE;
+                       opt_ipproto_off = ETH_HLEN + sizeof(struct ipv6hdr)
+                               + offsetof(struct ip6_ext, ip6e_nxt);
+               }
        }
 
+       /* this filter validates the following:
+        *      - packet is IPv4/IPv6 according to the running test.
+        *      - packet is TCP. Also handles the case of one extension header and then TCP.
+        *      - checks the packet tcp dport equals to DPORT. Also handles the case of one
+        *        extension header and then TCP.
+        */
        struct sock_filter filter[] = {
                        BPF_STMT(BPF_LD  + BPF_H   + BPF_ABS, ethproto_off),
-                       BPF_JUMP(BPF_JMP + BPF_JEQ + BPF_K, ntohs(ethhdr_proto), 0, 7),
+                       BPF_JUMP(BPF_JMP + BPF_JEQ + BPF_K, ntohs(ethhdr_proto), 0, 9),
                        BPF_STMT(BPF_LD  + BPF_B   + BPF_ABS, ipproto_off),
+                       BPF_JUMP(BPF_JMP + BPF_JEQ + BPF_K, IPPROTO_TCP, 2, 0),
+                       BPF_STMT(BPF_LD  + BPF_B   + BPF_ABS, opt_ipproto_off),
                        BPF_JUMP(BPF_JMP + BPF_JEQ + BPF_K, IPPROTO_TCP, 0, 5),
                        BPF_STMT(BPF_LD  + BPF_H   + BPF_ABS, dport_off),
                        BPF_JUMP(BPF_JMP + BPF_JEQ + BPF_K, DPORT, 2, 0),
@@ -576,6 +598,39 @@ static void add_ipv4_ts_option(void *buf, void *optpkt)
        iph->check = checksum_fold(iph, sizeof(struct iphdr) + optlen, 0);
 }
 
+static void add_ipv6_exthdr(void *buf, void *optpkt, __u8 exthdr_type, char *ext_payload)
+{
+       struct ipv6_opt_hdr *exthdr = (struct ipv6_opt_hdr *)(optpkt + tcp_offset);
+       struct ipv6hdr *iph = (struct ipv6hdr *)(optpkt + ETH_HLEN);
+       char *exthdr_payload_start = (char *)(exthdr + 1);
+
+       exthdr->hdrlen = 0;
+       exthdr->nexthdr = IPPROTO_TCP;
+
+       memcpy(exthdr_payload_start, ext_payload, MIN_EXTHDR_SIZE - sizeof(*exthdr));
+
+       memcpy(optpkt, buf, tcp_offset);
+       memcpy(optpkt + tcp_offset + MIN_EXTHDR_SIZE, buf + tcp_offset,
+               sizeof(struct tcphdr) + PAYLOAD_LEN);
+
+       iph->nexthdr = exthdr_type;
+       iph->payload_len = htons(ntohs(iph->payload_len) + MIN_EXTHDR_SIZE);
+}
+
+static void send_ipv6_exthdr(int fd, struct sockaddr_ll *daddr, char *ext_data1, char *ext_data2)
+{
+       static char buf[MAX_HDR_LEN + PAYLOAD_LEN];
+       static char exthdr_pck[sizeof(buf) + MIN_EXTHDR_SIZE];
+
+       create_packet(buf, 0, 0, PAYLOAD_LEN, 0);
+       add_ipv6_exthdr(buf, exthdr_pck, IPPROTO_HOPOPTS, ext_data1);
+       write_packet(fd, exthdr_pck, total_hdr_len + PAYLOAD_LEN + MIN_EXTHDR_SIZE, daddr);
+
+       create_packet(buf, PAYLOAD_LEN * 1, 0, PAYLOAD_LEN, 0);
+       add_ipv6_exthdr(buf, exthdr_pck, IPPROTO_HOPOPTS, ext_data2);
+       write_packet(fd, exthdr_pck, total_hdr_len + PAYLOAD_LEN + MIN_EXTHDR_SIZE, daddr);
+}
+
 /* IPv4 options shouldn't coalesce */
 static void send_ip_options(int fd, struct sockaddr_ll *daddr)
 {
@@ -697,7 +752,7 @@ static void send_fragment6(int fd, struct sockaddr_ll *daddr)
                create_packet(buf, PAYLOAD_LEN * i, 0, PAYLOAD_LEN, 0);
                write_packet(fd, buf, bufpkt_len, daddr);
        }
-
+       sleep(1);
        create_packet(buf, PAYLOAD_LEN * 2, 0, PAYLOAD_LEN, 0);
        memset(extpkt, 0, extpkt_len);
 
@@ -760,6 +815,7 @@ static void check_recv_pkts(int fd, int *correct_payload,
        vlog("}, Total %d packets\nReceived {", correct_num_pkts);
 
        while (1) {
+               ip_ext_len = 0;
                pkt_size = recv(fd, buffer, IP_MAXPACKET + ETH_HLEN + 1, 0);
                if (pkt_size < 0)
                        error(1, errno, "could not receive");
@@ -767,7 +823,7 @@ static void check_recv_pkts(int fd, int *correct_payload,
                if (iph->version == 4)
                        ip_ext_len = (iph->ihl - 5) * 4;
                else if (ip6h->version == 6 && ip6h->nexthdr != IPPROTO_TCP)
-                       ip_ext_len = sizeof(struct ip6_frag);
+                       ip_ext_len = MIN_EXTHDR_SIZE;
 
                tcph = (struct tcphdr *)(buffer + tcp_offset + ip_ext_len);
 
@@ -880,7 +936,21 @@ static void gro_sender(void)
                        sleep(1);
                        write_packet(txfd, fin_pkt, total_hdr_len, &daddr);
                } else if (proto == PF_INET6) {
+                       sleep(1);
                        send_fragment6(txfd, &daddr);
+                       sleep(1);
+                       write_packet(txfd, fin_pkt, total_hdr_len, &daddr);
+
+                       sleep(1);
+                       /* send IPv6 packets with ext header with same payload */
+                       send_ipv6_exthdr(txfd, &daddr, EXT_PAYLOAD_1, EXT_PAYLOAD_1);
+                       sleep(1);
+                       write_packet(txfd, fin_pkt, total_hdr_len, &daddr);
+
+                       sleep(1);
+                       /* send IPv6 packets with ext header with different payload */
+                       send_ipv6_exthdr(txfd, &daddr, EXT_PAYLOAD_1, EXT_PAYLOAD_2);
+                       sleep(1);
                        write_packet(txfd, fin_pkt, total_hdr_len, &daddr);
                }
        } else if (strcmp(testname, "large") == 0) {
@@ -997,6 +1067,17 @@ static void gro_receiver(void)
                         */
                        printf("fragmented ip6 doesn't coalesce: ");
                        correct_payload[0] = PAYLOAD_LEN * 2;
+                       correct_payload[1] = PAYLOAD_LEN;
+                       correct_payload[2] = PAYLOAD_LEN;
+                       check_recv_pkts(rxfd, correct_payload, 3);
+
+                       printf("ipv6 with ext header does coalesce: ");
+                       correct_payload[0] = PAYLOAD_LEN * 2;
+                       check_recv_pkts(rxfd, correct_payload, 1);
+
+                       printf("ipv6 with ext header with different payloads doesn't coalesce: ");
+                       correct_payload[0] = PAYLOAD_LEN;
+                       correct_payload[1] = PAYLOAD_LEN;
                        check_recv_pkts(rxfd, correct_payload, 2);
                }
        } else if (strcmp(testname, "large") == 0) {