From a541cfd31dca351a736362b4e06b626236f340dd Mon Sep 17 00:00:00 2001 From: Matthew Smith Date: Mon, 12 Feb 2024 18:39:21 +0000 Subject: ipsec: check each packet for no algs in esp-encrypt In esp_encrypt_inline(), if two or more consecutive packets are associated with the same SA which has no crypto or integrity algorithms set, only the first one gets dropped. Subsequent packets either get sent (synchronous crypto) or cause a segv (asynchronous crypto). The current SA's index and pool entry are cached before it can be determined whether the packet should be dropped due to no algorithms being set. The check for no algorithms is only performed when the cached SA index is different than the SA index for the current packet. So packets after the first one associated with the "none" alg SA aren't handled properly. This was broken by my previous commit ("ipsec: keep esp encrypt pointer and index synced") which fixed a segv that occurred under a different set of circumstances. Check whether each packet should be dropped instead of only checking when a new SA is encountered. Update unit tests: - Add a test for no algs on tunnel interface which enables asynchronous crypto. - Send more than one packet in the tests for no algs. Type: fix Fixes: dac9e566cd16fc375fff14280b37cb5135584fc6 Signed-off-by: Matthew Smith Change-Id: I69e951f22044051eb8557da187cb58f5535b54bf (cherry picked from commit ff71939c30ae81241808da1843e82cf2dfa92344) --- src/vnet/ipsec/esp_encrypt.c | 23 +++++++++++++---------- test/test_ipsec_tun_if_esp.py | 24 +++++++++++++++++++++++- 2 files changed, 36 insertions(+), 11 deletions(-) diff --git a/src/vnet/ipsec/esp_encrypt.c b/src/vnet/ipsec/esp_encrypt.c index 8a1ac7e1ebb..46f7fe6cd06 100644 --- a/src/vnet/ipsec/esp_encrypt.c +++ b/src/vnet/ipsec/esp_encrypt.c @@ -607,6 +607,7 @@ esp_encrypt_inline (vlib_main_t *vm, vlib_node_runtime_t *node, u32 current_sa_bytes = 0, spi = 0; u8 esp_align = 4, iv_sz = 0, icv_sz = 0; ipsec_sa_t *sa0 = 0; + u8 sa_drop_no_crypto = 0; vlib_buffer_t *lb; vnet_crypto_op_t **crypto_ops = &ptd->crypto_ops; vnet_crypto_op_t **integ_ops = &ptd->integ_ops; @@ -692,16 +693,10 @@ esp_encrypt_inline (vlib_main_t *vm, vlib_node_runtime_t *node, sa0 = ipsec_sa_get (sa_index0); current_sa_index = sa_index0; - if (PREDICT_FALSE ((sa0->crypto_alg == IPSEC_CRYPTO_ALG_NONE && - sa0->integ_alg == IPSEC_INTEG_ALG_NONE) && - !ipsec_sa_is_set_NO_ALGO_NO_DROP (sa0))) - { - err = ESP_ENCRYPT_ERROR_NO_ENCRYPTION; - esp_encrypt_set_next_index (b[0], node, thread_index, err, - n_noop, noop_nexts, drop_next, - sa_index0); - goto trace; - } + sa_drop_no_crypto = ((sa0->crypto_alg == IPSEC_CRYPTO_ALG_NONE && + sa0->integ_alg == IPSEC_INTEG_ALG_NONE) && + !ipsec_sa_is_set_NO_ALGO_NO_DROP (sa0)); + vlib_prefetch_combined_counter (&ipsec_sa_counters, thread_index, current_sa_index); @@ -715,6 +710,14 @@ esp_encrypt_inline (vlib_main_t *vm, vlib_node_runtime_t *node, is_async = im->async_mode | ipsec_sa_is_set_IS_ASYNC (sa0); } + if (PREDICT_FALSE (sa_drop_no_crypto != 0)) + { + err = ESP_ENCRYPT_ERROR_NO_ENCRYPTION; + esp_encrypt_set_next_index (b[0], node, thread_index, err, n_noop, + noop_nexts, drop_next, sa_index0); + goto trace; + } + if (PREDICT_FALSE ((u16) ~0 == sa0->thread_index)) { /* this is the first packet to use this SA, claim the SA diff --git a/test/test_ipsec_tun_if_esp.py b/test/test_ipsec_tun_if_esp.py index 5131fbefe7d..a7f91b9e967 100644 --- a/test/test_ipsec_tun_if_esp.py +++ b/test/test_ipsec_tun_if_esp.py @@ -1231,13 +1231,35 @@ class TestIpsec4TunIfEspNoAlgo(TemplateIpsec4TunProtect, TemplateIpsec, IpsecTun self.config_sa_tra(p) self.config_protect(p) - tx = self.gen_pkts(self.pg1, src=self.pg1.remote_ip4, dst=p.remote_tun_if_host) + tx = self.gen_pkts( + self.pg1, src=self.pg1.remote_ip4, dst=p.remote_tun_if_host, count=127 + ) self.send_and_assert_no_replies(self.pg1, tx) self.unconfig_protect(p) self.unconfig_sa(p) self.unconfig_network(p) + def test_tun_44_async(self): + """IPSec SA with NULL algos using async crypto""" + p = self.ipv4_params + + self.vapi.ipsec_set_async_mode(async_enable=True) + self.config_network(p) + self.config_sa_tra(p) + self.config_protect(p) + + tx = self.gen_pkts( + self.pg1, src=self.pg1.remote_ip4, dst=p.remote_tun_if_host, count=127 + ) + self.send_and_assert_no_replies(self.pg1, tx) + + self.unconfig_protect(p) + self.unconfig_sa(p) + self.unconfig_network(p) + + self.vapi.ipsec_set_async_mode(async_enable=False) + @tag_fixme_vpp_workers class TestIpsec6MultiTunIfEsp(TemplateIpsec6TunProtect, TemplateIpsec, IpsecTun6): -- cgit 1.2.3-korg