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-rw-r--r--include/net/tcp.h10
-rw-r--r--include/uapi/linux/bpf.h30
-rw-r--r--net/core/filter.c73
-rw-r--r--net/ipv4/tcp_input.c81
-rw-r--r--net/ipv4/tcp_ipv4.c15
-rw-r--r--net/ipv6/tcp_ipv6.c15
-rw-r--r--tools/include/uapi/linux/bpf.h37
-rw-r--r--tools/testing/selftests/bpf/bpf_helpers.h3
-rw-r--r--tools/testing/selftests/bpf/progs/test_tcp_check_syncookie_kern.c48
-rwxr-xr-xtools/testing/selftests/bpf/test_tcp_check_syncookie.sh3
-rw-r--r--tools/testing/selftests/bpf/test_tcp_check_syncookie_user.c61
11 files changed, 354 insertions, 22 deletions
diff --git a/include/net/tcp.h b/include/net/tcp.h
index e5cf514ba118..fb7e153aecc5 100644
--- a/include/net/tcp.h
+++ b/include/net/tcp.h
@@ -415,6 +415,16 @@ void tcp_parse_options(const struct net *net, const struct sk_buff *skb,
const u8 *tcp_parse_md5sig_option(const struct tcphdr *th);
/*
+ * BPF SKB-less helpers
+ */
+u16 tcp_v4_get_syncookie(struct sock *sk, struct iphdr *iph,
+ struct tcphdr *th, u32 *cookie);
+u16 tcp_v6_get_syncookie(struct sock *sk, struct ipv6hdr *iph,
+ struct tcphdr *th, u32 *cookie);
+u16 tcp_get_syncookie_mss(struct request_sock_ops *rsk_ops,
+ const struct tcp_request_sock_ops *af_ops,
+ struct sock *sk, struct tcphdr *th);
+/*
* TCP v4 functions exported for the inet6 API
*/
diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h
index 6bbef0c7f585..4393bd4b2419 100644
--- a/include/uapi/linux/bpf.h
+++ b/include/uapi/linux/bpf.h
@@ -2714,6 +2714,33 @@ union bpf_attr {
* **-EPERM** if no permission to send the *sig*.
*
* **-EAGAIN** if bpf program can try again.
+ *
+ * s64 bpf_tcp_gen_syncookie(struct bpf_sock *sk, void *iph, u32 iph_len, struct tcphdr *th, u32 th_len)
+ * Description
+ * Try to issue a SYN cookie for the packet with corresponding
+ * IP/TCP headers, *iph* and *th*, on the listening socket in *sk*.
+ *
+ * *iph* points to the start of the IPv4 or IPv6 header, while
+ * *iph_len* contains **sizeof**\ (**struct iphdr**) or
+ * **sizeof**\ (**struct ip6hdr**).
+ *
+ * *th* points to the start of the TCP header, while *th_len*
+ * contains the length of the TCP header.
+ *
+ * Return
+ * On success, lower 32 bits hold the generated SYN cookie in
+ * followed by 16 bits which hold the MSS value for that cookie,
+ * and the top 16 bits are unused.
+ *
+ * On failure, the returned value is one of the following:
+ *
+ * **-EINVAL** SYN cookie cannot be issued due to error
+ *
+ * **-ENOENT** SYN cookie should not be issued (no SYN flood)
+ *
+ * **-EOPNOTSUPP** kernel configuration does not enable SYN cookies
+ *
+ * **-EPROTONOSUPPORT** IP packet version is not 4 or 6
*/
#define __BPF_FUNC_MAPPER(FN) \
FN(unspec), \
@@ -2825,7 +2852,8 @@ union bpf_attr {
FN(strtoul), \
FN(sk_storage_get), \
FN(sk_storage_delete), \
- FN(send_signal),
+ FN(send_signal), \
+ FN(tcp_gen_syncookie),
/* integer value in 'imm' field of BPF_CALL instruction selects which helper
* function eBPF program intends to call
diff --git a/net/core/filter.c b/net/core/filter.c
index 1eee70f80fba..5a2707918629 100644
--- a/net/core/filter.c
+++ b/net/core/filter.c
@@ -5855,6 +5855,75 @@ static const struct bpf_func_proto bpf_tcp_check_syncookie_proto = {
.arg5_type = ARG_CONST_SIZE,
};
+BPF_CALL_5(bpf_tcp_gen_syncookie, struct sock *, sk, void *, iph, u32, iph_len,
+ struct tcphdr *, th, u32, th_len)
+{
+#ifdef CONFIG_SYN_COOKIES
+ u32 cookie;
+ u16 mss;
+
+ if (unlikely(th_len < sizeof(*th) || th_len != th->doff * 4))
+ return -EINVAL;
+
+ if (sk->sk_protocol != IPPROTO_TCP || sk->sk_state != TCP_LISTEN)
+ return -EINVAL;
+
+ if (!sock_net(sk)->ipv4.sysctl_tcp_syncookies)
+ return -ENOENT;
+
+ if (!th->syn || th->ack || th->fin || th->rst)
+ return -EINVAL;
+
+ if (unlikely(iph_len < sizeof(struct iphdr)))
+ return -EINVAL;
+
+ /* Both struct iphdr and struct ipv6hdr have the version field at the
+ * same offset so we can cast to the shorter header (struct iphdr).
+ */
+ switch (((struct iphdr *)iph)->version) {
+ case 4:
+ if (sk->sk_family == AF_INET6 && sk->sk_ipv6only)
+ return -EINVAL;
+
+ mss = tcp_v4_get_syncookie(sk, iph, th, &cookie);
+ break;
+
+#if IS_BUILTIN(CONFIG_IPV6)
+ case 6:
+ if (unlikely(iph_len < sizeof(struct ipv6hdr)))
+ return -EINVAL;
+
+ if (sk->sk_family != AF_INET6)
+ return -EINVAL;
+
+ mss = tcp_v6_get_syncookie(sk, iph, th, &cookie);
+ break;
+#endif /* CONFIG_IPV6 */
+
+ default:
+ return -EPROTONOSUPPORT;
+ }
+ if (mss <= 0)
+ return -ENOENT;
+
+ return cookie | ((u64)mss << 32);
+#else
+ return -EOPNOTSUPP;
+#endif /* CONFIG_SYN_COOKIES */
+}
+
+static const struct bpf_func_proto bpf_tcp_gen_syncookie_proto = {
+ .func = bpf_tcp_gen_syncookie,
+ .gpl_only = true, /* __cookie_v*_init_sequence() is GPL */
+ .pkt_access = true,
+ .ret_type = RET_INTEGER,
+ .arg1_type = ARG_PTR_TO_SOCK_COMMON,
+ .arg2_type = ARG_PTR_TO_MEM,
+ .arg3_type = ARG_CONST_SIZE,
+ .arg4_type = ARG_PTR_TO_MEM,
+ .arg5_type = ARG_CONST_SIZE,
+};
+
#endif /* CONFIG_INET */
bool bpf_helper_changes_pkt_data(void *func)
@@ -6144,6 +6213,8 @@ tc_cls_act_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
return &bpf_tcp_check_syncookie_proto;
case BPF_FUNC_skb_ecn_set_ce:
return &bpf_skb_ecn_set_ce_proto;
+ case BPF_FUNC_tcp_gen_syncookie:
+ return &bpf_tcp_gen_syncookie_proto;
#endif
default:
return bpf_base_func_proto(func_id);
@@ -6183,6 +6254,8 @@ xdp_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
return &bpf_xdp_skc_lookup_tcp_proto;
case BPF_FUNC_tcp_check_syncookie:
return &bpf_tcp_check_syncookie_proto;
+ case BPF_FUNC_tcp_gen_syncookie:
+ return &bpf_tcp_gen_syncookie_proto;
#endif
default:
return bpf_base_func_proto(func_id);
diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
index c21e8a22fb3b..706cbb3b2986 100644
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c
@@ -3782,6 +3782,49 @@ static void smc_parse_options(const struct tcphdr *th,
#endif
}
+/* Try to parse the MSS option from the TCP header. Return 0 on failure, clamped
+ * value on success.
+ */
+static u16 tcp_parse_mss_option(const struct tcphdr *th, u16 user_mss)
+{
+ const unsigned char *ptr = (const unsigned char *)(th + 1);
+ int length = (th->doff * 4) - sizeof(struct tcphdr);
+ u16 mss = 0;
+
+ while (length > 0) {
+ int opcode = *ptr++;
+ int opsize;
+
+ switch (opcode) {
+ case TCPOPT_EOL:
+ return mss;
+ case TCPOPT_NOP: /* Ref: RFC 793 section 3.1 */
+ length--;
+ continue;
+ default:
+ if (length < 2)
+ return mss;
+ opsize = *ptr++;
+ if (opsize < 2) /* "silly options" */
+ return mss;
+ if (opsize > length)
+ return mss; /* fail on partial options */
+ if (opcode == TCPOPT_MSS && opsize == TCPOLEN_MSS) {
+ u16 in_mss = get_unaligned_be16(ptr);
+
+ if (in_mss) {
+ if (user_mss && user_mss < in_mss)
+ in_mss = user_mss;
+ mss = in_mss;
+ }
+ }
+ ptr += opsize - 2;
+ length -= opsize;
+ }
+ }
+ return mss;
+}
+
/* Look for tcp options. Normally only called on SYN and SYNACK packets.
* But, this can also be called on packets in the established flow when
* the fast version below fails.
@@ -6422,9 +6465,7 @@ EXPORT_SYMBOL(inet_reqsk_alloc);
/*
* Return true if a syncookie should be sent
*/
-static bool tcp_syn_flood_action(const struct sock *sk,
- const struct sk_buff *skb,
- const char *proto)
+static bool tcp_syn_flood_action(const struct sock *sk, const char *proto)
{
struct request_sock_queue *queue = &inet_csk(sk)->icsk_accept_queue;
const char *msg = "Dropping request";
@@ -6444,7 +6485,7 @@ static bool tcp_syn_flood_action(const struct sock *sk,
net->ipv4.sysctl_tcp_syncookies != 2 &&
xchg(&queue->synflood_warned, 1) == 0)
net_info_ratelimited("%s: Possible SYN flooding on port %d. %s. Check SNMP counters.\n",
- proto, ntohs(tcp_hdr(skb)->dest), msg);
+ proto, sk->sk_num, msg);
return want_cookie;
}
@@ -6466,6 +6507,36 @@ static void tcp_reqsk_record_syn(const struct sock *sk,
}
}
+/* If a SYN cookie is required and supported, returns a clamped MSS value to be
+ * used for SYN cookie generation.
+ */
+u16 tcp_get_syncookie_mss(struct request_sock_ops *rsk_ops,
+ const struct tcp_request_sock_ops *af_ops,
+ struct sock *sk, struct tcphdr *th)
+{
+ struct tcp_sock *tp = tcp_sk(sk);
+ u16 mss;
+
+ if (sock_net(sk)->ipv4.sysctl_tcp_syncookies != 2 &&
+ !inet_csk_reqsk_queue_is_full(sk))
+ return 0;
+
+ if (!tcp_syn_flood_action(sk, rsk_ops->slab_name))
+ return 0;
+
+ if (sk_acceptq_is_full(sk)) {
+ NET_INC_STATS(sock_net(sk), LINUX_MIB_LISTENOVERFLOWS);
+ return 0;
+ }
+
+ mss = tcp_parse_mss_option(th, tp->rx_opt.user_mss);
+ if (!mss)
+ mss = af_ops->mss_clamp;
+
+ return mss;
+}
+EXPORT_SYMBOL_GPL(tcp_get_syncookie_mss);
+
int tcp_conn_request(struct request_sock_ops *rsk_ops,
const struct tcp_request_sock_ops *af_ops,
struct sock *sk, struct sk_buff *skb)
@@ -6487,7 +6558,7 @@ int tcp_conn_request(struct request_sock_ops *rsk_ops,
*/
if ((net->ipv4.sysctl_tcp_syncookies == 2 ||
inet_csk_reqsk_queue_is_full(sk)) && !isn) {
- want_cookie = tcp_syn_flood_action(sk, skb, rsk_ops->slab_name);
+ want_cookie = tcp_syn_flood_action(sk, rsk_ops->slab_name);
if (!want_cookie)
goto drop;
}
diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c
index d57641cb3477..10217393cda6 100644
--- a/net/ipv4/tcp_ipv4.c
+++ b/net/ipv4/tcp_ipv4.c
@@ -1515,6 +1515,21 @@ static struct sock *tcp_v4_cookie_check(struct sock *sk, struct sk_buff *skb)
return sk;
}
+u16 tcp_v4_get_syncookie(struct sock *sk, struct iphdr *iph,
+ struct tcphdr *th, u32 *cookie)
+{
+ u16 mss = 0;
+#ifdef CONFIG_SYN_COOKIES
+ mss = tcp_get_syncookie_mss(&tcp_request_sock_ops,
+ &tcp_request_sock_ipv4_ops, sk, th);
+ if (mss) {
+ *cookie = __cookie_v4_init_sequence(iph, th, &mss);
+ tcp_synq_overflow(sk);
+ }
+#endif
+ return mss;
+}
+
/* The socket must have it's spinlock held when we get
* here, unless it is a TCP_LISTEN socket.
*
diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c
index 5da069e91cac..87f44d3250ee 100644
--- a/net/ipv6/tcp_ipv6.c
+++ b/net/ipv6/tcp_ipv6.c
@@ -1063,6 +1063,21 @@ static struct sock *tcp_v6_cookie_check(struct sock *sk, struct sk_buff *skb)
return sk;
}
+u16 tcp_v6_get_syncookie(struct sock *sk, struct ipv6hdr *iph,
+ struct tcphdr *th, u32 *cookie)
+{
+ u16 mss = 0;
+#ifdef CONFIG_SYN_COOKIES
+ mss = tcp_get_syncookie_mss(&tcp6_request_sock_ops,
+ &tcp_request_sock_ipv6_ops, sk, th);
+ if (mss) {
+ *cookie = __cookie_v6_init_sequence(iph, th, &mss);
+ tcp_synq_overflow(sk);
+ }
+#endif
+ return mss;
+}
+
static int tcp_v6_conn_request(struct sock *sk, struct sk_buff *skb)
{
if (skb->protocol == htons(ETH_P_IP))
diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h
index 21d0f6863df3..4393bd4b2419 100644
--- a/tools/include/uapi/linux/bpf.h
+++ b/tools/include/uapi/linux/bpf.h
@@ -1572,8 +1572,11 @@ union bpf_attr {
* but this is only implemented for native XDP (with driver
* support) as of this writing).
*
- * All values for *flags* are reserved for future usage, and must
- * be left at zero.
+ * The lower two bits of *flags* are used as the return code if
+ * the map lookup fails. This is so that the return value can be
+ * one of the XDP program return codes up to XDP_TX, as chosen by
+ * the caller. Any higher bits in the *flags* argument must be
+ * unset.
*
* When used to redirect packets to net devices, this helper
* provides a high performance increase over **bpf_redirect**\ ().
@@ -2711,6 +2714,33 @@ union bpf_attr {
* **-EPERM** if no permission to send the *sig*.
*
* **-EAGAIN** if bpf program can try again.
+ *
+ * s64 bpf_tcp_gen_syncookie(struct bpf_sock *sk, void *iph, u32 iph_len, struct tcphdr *th, u32 th_len)
+ * Description
+ * Try to issue a SYN cookie for the packet with corresponding
+ * IP/TCP headers, *iph* and *th*, on the listening socket in *sk*.
+ *
+ * *iph* points to the start of the IPv4 or IPv6 header, while
+ * *iph_len* contains **sizeof**\ (**struct iphdr**) or
+ * **sizeof**\ (**struct ip6hdr**).
+ *
+ * *th* points to the start of the TCP header, while *th_len*
+ * contains the length of the TCP header.
+ *
+ * Return
+ * On success, lower 32 bits hold the generated SYN cookie in
+ * followed by 16 bits which hold the MSS value for that cookie,
+ * and the top 16 bits are unused.
+ *
+ * On failure, the returned value is one of the following:
+ *
+ * **-EINVAL** SYN cookie cannot be issued due to error
+ *
+ * **-ENOENT** SYN cookie should not be issued (no SYN flood)
+ *
+ * **-EOPNOTSUPP** kernel configuration does not enable SYN cookies
+ *
+ * **-EPROTONOSUPPORT** IP packet version is not 4 or 6
*/
#define __BPF_FUNC_MAPPER(FN) \
FN(unspec), \
@@ -2822,7 +2852,8 @@ union bpf_attr {
FN(strtoul), \
FN(sk_storage_get), \
FN(sk_storage_delete), \
- FN(send_signal),
+ FN(send_signal), \
+ FN(tcp_gen_syncookie),
/* integer value in 'imm' field of BPF_CALL instruction selects which helper
* function eBPF program intends to call
diff --git a/tools/testing/selftests/bpf/bpf_helpers.h b/tools/testing/selftests/bpf/bpf_helpers.h
index f804f210244e..120aa86c58d3 100644
--- a/tools/testing/selftests/bpf/bpf_helpers.h
+++ b/tools/testing/selftests/bpf/bpf_helpers.h
@@ -228,6 +228,9 @@ static void *(*bpf_sk_storage_get)(void *map, struct bpf_sock *sk,
static int (*bpf_sk_storage_delete)(void *map, struct bpf_sock *sk) =
(void *)BPF_FUNC_sk_storage_delete;
static int (*bpf_send_signal)(unsigned sig) = (void *)BPF_FUNC_send_signal;
+static long long (*bpf_tcp_gen_syncookie)(struct bpf_sock *sk, void *ip,
+ int ip_len, void *tcp, int tcp_len) =
+ (void *) BPF_FUNC_tcp_gen_syncookie;
/* llvm builtin functions that eBPF C program may use to
* emit BPF_LD_ABS and BPF_LD_IND instructions
diff --git a/tools/testing/selftests/bpf/progs/test_tcp_check_syncookie_kern.c b/tools/testing/selftests/bpf/progs/test_tcp_check_syncookie_kern.c
index 1ab095bcacd8..d8803dfa8d32 100644
--- a/tools/testing/selftests/bpf/progs/test_tcp_check_syncookie_kern.c
+++ b/tools/testing/selftests/bpf/progs/test_tcp_check_syncookie_kern.c
@@ -19,10 +19,29 @@
struct bpf_map_def SEC("maps") results = {
.type = BPF_MAP_TYPE_ARRAY,
.key_size = sizeof(__u32),
- .value_size = sizeof(__u64),
- .max_entries = 1,
+ .value_size = sizeof(__u32),
+ .max_entries = 3,
};
+static __always_inline __s64 gen_syncookie(void *data_end, struct bpf_sock *sk,
+ void *iph, __u32 ip_size,
+ struct tcphdr *tcph)
+{
+ __u32 thlen = tcph->doff * 4;
+
+ if (tcph->syn && !tcph->ack) {
+ // packet should only have an MSS option
+ if (thlen != 24)
+ return 0;
+
+ if ((void *)tcph + thlen > data_end)
+ return 0;
+
+ return bpf_tcp_gen_syncookie(sk, iph, ip_size, tcph, thlen);
+ }
+ return 0;
+}
+
static __always_inline void check_syncookie(void *ctx, void *data,
void *data_end)
{
@@ -33,8 +52,10 @@ static __always_inline void check_syncookie(void *ctx, void *data,
struct ipv6hdr *ipv6h;
struct tcphdr *tcph;
int ret;
+ __u32 key_mss = 2;
+ __u32 key_gen = 1;
__u32 key = 0;
- __u64 value = 1;
+ __s64 seq_mss;
ethh = data;
if (ethh + 1 > data_end)
@@ -66,6 +87,9 @@ static __always_inline void check_syncookie(void *ctx, void *data,
if (sk->state != BPF_TCP_LISTEN)
goto release;
+ seq_mss = gen_syncookie(data_end, sk, ipv4h, sizeof(*ipv4h),
+ tcph);
+
ret = bpf_tcp_check_syncookie(sk, ipv4h, sizeof(*ipv4h),
tcph, sizeof(*tcph));
break;
@@ -95,6 +119,9 @@ static __always_inline void check_syncookie(void *ctx, void *data,
if (sk->state != BPF_TCP_LISTEN)
goto release;
+ seq_mss = gen_syncookie(data_end, sk, ipv6h, sizeof(*ipv6h),
+ tcph);
+
ret = bpf_tcp_check_syncookie(sk, ipv6h, sizeof(*ipv6h),
tcph, sizeof(*tcph));
break;
@@ -103,8 +130,19 @@ static __always_inline void check_syncookie(void *ctx, void *data,
return;
}
- if (ret == 0)
- bpf_map_update_elem(&results, &key, &value, 0);
+ if (seq_mss > 0) {
+ __u32 cookie = (__u32)seq_mss;
+ __u32 mss = seq_mss >> 32;
+
+ bpf_map_update_elem(&results, &key_gen, &cookie, 0);
+ bpf_map_update_elem(&results, &key_mss, &mss, 0);
+ }
+
+ if (ret == 0) {
+ __u32 cookie = bpf_ntohl(tcph->ack_seq) - 1;
+
+ bpf_map_update_elem(&results, &key, &cookie, 0);
+ }
release:
bpf_sk_release(sk);
diff --git a/tools/testing/selftests/bpf/test_tcp_check_syncookie.sh b/tools/testing/selftests/bpf/test_tcp_check_syncookie.sh
index d48e51716d19..9b3617d770a5 100755
--- a/tools/testing/selftests/bpf/test_tcp_check_syncookie.sh
+++ b/tools/testing/selftests/bpf/test_tcp_check_syncookie.sh
@@ -37,6 +37,9 @@ setup()
ns1_exec ip link set lo up
ns1_exec sysctl -w net.ipv4.tcp_syncookies=2
+ ns1_exec sysctl -w net.ipv4.tcp_window_scaling=0
+ ns1_exec sysctl -w net.ipv4.tcp_timestamps=0
+ ns1_exec sysctl -w net.ipv4.tcp_sack=0
wait_for_ip 127.0.0.1
wait_for_ip ::1
diff --git a/tools/testing/selftests/bpf/test_tcp_check_syncookie_user.c b/tools/testing/selftests/bpf/test_tcp_check_syncookie_user.c
index 87829c86c746..b9e991d43155 100644
--- a/tools/testing/selftests/bpf/test_tcp_check_syncookie_user.c
+++ b/tools/testing/selftests/bpf/test_tcp_check_syncookie_user.c
@@ -2,6 +2,7 @@
// Copyright (c) 2018 Facebook
// Copyright (c) 2019 Cloudflare
+#include <limits.h>
#include <string.h>
#include <stdlib.h>
#include <unistd.h>
@@ -77,7 +78,7 @@ out:
return fd;
}
-static int get_map_fd_by_prog_id(int prog_id)
+static int get_map_fd_by_prog_id(int prog_id, bool *xdp)
{
struct bpf_prog_info info = {};
__u32 info_len = sizeof(info);
@@ -104,6 +105,8 @@ static int get_map_fd_by_prog_id(int prog_id)
goto err;
}
+ *xdp = info.type == BPF_PROG_TYPE_XDP;
+
map_fd = bpf_map_get_fd_by_id(map_ids[0]);
if (map_fd < 0)
log_err("Failed to get fd by map id %d", map_ids[0]);
@@ -113,18 +116,32 @@ err:
return map_fd;
}
-static int run_test(int server_fd, int results_fd)
+static int run_test(int server_fd, int results_fd, bool xdp)
{
int client = -1, srv_client = -1;
int ret = 0;
__u32 key = 0;
- __u64 value = 0;
+ __u32 key_gen = 1;
+ __u32 key_mss = 2;
+ __u32 value = 0;
+ __u32 value_gen = 0;
+ __u32 value_mss = 0;
if (bpf_map_update_elem(results_fd, &key, &value, 0) < 0) {
log_err("Can't clear results");
goto err;
}
+ if (bpf_map_update_elem(results_fd, &key_gen, &value_gen, 0) < 0) {
+ log_err("Can't clear results");
+ goto err;
+ }
+
+ if (bpf_map_update_elem(results_fd, &key_mss, &value_mss, 0) < 0) {
+ log_err("Can't clear results");
+ goto err;
+ }
+
client = connect_to_server(server_fd);
if (client == -1)
goto err;
@@ -140,8 +157,35 @@ static int run_test(int server_fd, int results_fd)
goto err;
}
- if (value != 1) {
- log_err("Didn't match syncookie: %llu", value);
+ if (value == 0) {
+ log_err("Didn't match syncookie: %u", value);
+ goto err;
+ }
+
+ if (bpf_map_lookup_elem(results_fd, &key_gen, &value_gen) < 0) {
+ log_err("Can't lookup result");
+ goto err;
+ }
+
+ if (xdp && value_gen == 0) {
+ // SYN packets do not get passed through generic XDP, skip the
+ // rest of the test.
+ printf("Skipping XDP cookie check\n");
+ goto out;
+ }
+
+ if (bpf_map_lookup_elem(results_fd, &key_mss, &value_mss) < 0) {
+ log_err("Can't lookup result");
+ goto err;
+ }
+
+ if (value != value_gen) {
+ log_err("BPF generated cookie does not match kernel one");
+ goto err;
+ }
+
+ if (value_mss < 536 || value_mss > USHRT_MAX) {
+ log_err("Unexpected MSS retrieved");
goto err;
}
@@ -163,13 +207,14 @@ int main(int argc, char **argv)
int server_v6 = -1;
int results = -1;
int err = 0;
+ bool xdp;
if (argc < 2) {
fprintf(stderr, "Usage: %s prog_id\n", argv[0]);
exit(1);
}
- results = get_map_fd_by_prog_id(atoi(argv[1]));
+ results = get_map_fd_by_prog_id(atoi(argv[1]), &xdp);
if (results < 0) {
log_err("Can't get map");
goto err;
@@ -194,10 +239,10 @@ int main(int argc, char **argv)
if (server_v6 == -1)
goto err;
- if (run_test(server, results))
+ if (run_test(server, results, xdp))
goto err;
- if (run_test(server_v6, results))
+ if (run_test(server_v6, results, xdp))
goto err;
printf("ok\n");