2024-01-02 13:29:35

by Richard Gobert

[permalink] [raw]
Subject: [PATCH net-next v2 3/3] 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 <[email protected]>
---
tools/testing/selftests/net/gro.c | 94 +++++++++++++++++++++++++++++--
1 file changed, 88 insertions(+), 6 deletions(-)

diff --git a/tools/testing/selftests/net/gro.c b/tools/testing/selftests/net/gro.c
index 30024d0ed373..6dbba8ec53a1 100644
--- 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 +598,40 @@ 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;
+
+ if (ext_payload)
+ 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 +753,7 @@ 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 +816,7 @@ 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 +824,7 @@ 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 +937,21 @@ 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 +1068,17 @@ 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) {
--
2.36.1



2024-01-02 15:09:23

by Willem de Bruijn

[permalink] [raw]
Subject: Re: [PATCH net-next v2 3/3] selftests/net: fix GRO coalesce test and add ext header coalesce tests

Richard Gobert wrote:
> 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 <[email protected]>

Reviewed-by: Willem de Bruijn <[email protected]>

Thanks for adding the second test.

> +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;
> +
> + if (ext_payload)
> + memcpy(exthdr_payload_start, ext_payload, MIN_EXTHDR_SIZE - sizeof(*exthdr));

minor nit, in case this gets respun: ext_payload is always true.