selftests/bpf: Fix msg_verify_data in test_sockmap

Function msg_verify_data should have context of bytes_cnt and k instead of
assuming they are zero. Otherwise, test_sockmap with data integrity test
will report some errors. I also fix the logic related to size and index j

1/ 6  sockmap::txmsg test passthrough:FAIL
2/ 6  sockmap::txmsg test redirect:FAIL
7/12  sockmap::txmsg test apply:FAIL
10/11  sockmap::txmsg test push_data:FAIL
11/17  sockmap::txmsg test pull-data:FAIL
12/ 9  sockmap::txmsg test pop-data:FAIL
13/ 1  sockmap::txmsg test push/pop data:FAIL
...
Pass: 24 Fail: 52

After applying this patch, some of the errors are solved, but for push,
pull and pop, we may need more fixes to msg_verify_data, added a TODO

10/11  sockmap::txmsg test push_data:FAIL
11/17  sockmap::txmsg test pull-data:FAIL
12/ 9  sockmap::txmsg test pop-data:FAIL
...
Pass: 37 Fail: 15

Besides, added a custom errno EDATAINTEGRITY for msg_verify_data, we
shall not ignore the error in txmsg_cork case.

Fixes: 753fb2ee0934 ("bpf: sockmap, add msg_peek tests to test_sockmap")
Fixes: 16edddfe3c5d ("selftests/bpf: test_sockmap, check test failure")
Acked-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Zijian Zhang <zijianzhang@bytedance.com>
Link: https://lore.kernel.org/r/20241012203731.1248619-2-zijianzhang@bytedance.com
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>

diff --git a/tools/testing/selftests/bpf/test_sockmap.c b/tools/testing/selftests/bpf/test_sockmap.c
index 3e02d7267de8bb557b12bcbc6b6675aab4d3097b..8249f3c1fbd659ef3867db8b62bec5351757c82a 100644 (file)
--- a/tools/testing/selftests/bpf/test_sockmap.c
+++ b/tools/testing/selftests/bpf/test_sockmap.c
@@ -56,6 +56,8 @@ static void running_handler(int a);
 #define BPF_SOCKHASH_FILENAME "test_sockhash_kern.bpf.o"
 #define CG_PATH "/sockmap"
 
+#define EDATAINTEGRITY 2001
+
 /* global sockets */
 int s1, s2, c1, c2, p1, p2;
 int test_cnt;
@@ -510,23 +512,25 @@ unwind_iov:
        return -ENOMEM;
 }
 
-static int msg_verify_data(struct msghdr *msg, int size, int chunk_sz)
+/* TODO: Add verification logic for push, pull and pop data */
+static int msg_verify_data(struct msghdr *msg, int size, int chunk_sz,
+                                unsigned char *k_p, int *bytes_cnt_p)
 {
-       int i, j = 0, bytes_cnt = 0;
-       unsigned char k = 0;
+       int i, j, bytes_cnt = *bytes_cnt_p;
+       unsigned char k = *k_p;
 
-       for (i = 0; i < msg->msg_iovlen; i++) {
+       for (i = 0, j = 0; i < msg->msg_iovlen && size; i++, j = 0) {
                unsigned char *d = msg->msg_iov[i].iov_base;
 
                /* Special case test for skb ingress + ktls */
                if (i == 0 && txmsg_ktls_skb) {
                        if (msg->msg_iov[i].iov_len < 4)
-                               return -EIO;
+                               return -EDATAINTEGRITY;
                        if (memcmp(d, "PASS", 4) != 0) {
                                fprintf(stderr,
                                        "detected skb data error with skb ingress update @iov[%i]:%i \"%02x %02x %02x %02x\" != \"PASS\"\n",
                                        i, 0, d[0], d[1], d[2], d[3]);
-                               return -EIO;
+                               return -EDATAINTEGRITY;
                        }
                        j = 4; /* advance index past PASS header */
                }
@@ -536,7 +540,7 @@ static int msg_verify_data(struct msghdr *msg, int size, int chunk_sz)
                                fprintf(stderr,
                                        "detected data corruption @iov[%i]:%i %02x != %02x, %02x ?= %02x\n",
                                        i, j, d[j], k - 1, d[j+1], k);
-                               return -EIO;
+                               return -EDATAINTEGRITY;
                        }
                        bytes_cnt++;
                        if (bytes_cnt == chunk_sz) {
@@ -546,6 +550,8 @@ static int msg_verify_data(struct msghdr *msg, int size, int chunk_sz)
                        size--;
                }
        }
+       *k_p = k;
+       *bytes_cnt_p = bytes_cnt;
        return 0;
 }
 
@@ -602,6 +608,8 @@ static int msg_loop(int fd, int iov_count, int iov_length, int cnt,
                float total_bytes, txmsg_pop_total;
                int fd_flags = O_NONBLOCK;
                struct timeval timeout;
+               unsigned char k = 0;
+               int bytes_cnt = 0;
                fd_set w;
 
                fcntl(fd, fd_flags);
@@ -696,7 +704,7 @@ static int msg_loop(int fd, int iov_count, int iov_length, int cnt,
                                                iov_length * cnt :
                                                iov_length * iov_count;
 
-                               errno = msg_verify_data(&msg, recv, chunk_sz);
+                               errno = msg_verify_data(&msg, recv, chunk_sz, &k, &bytes_cnt);
                                if (errno) {
                                        perror("data verify msg failed");
                                        goto out_errno;
@@ -704,7 +712,9 @@ static int msg_loop(int fd, int iov_count, int iov_length, int cnt,
                                if (recvp) {
                                        errno = msg_verify_data(&msg_peek,
                                                                recvp,
-                                                               chunk_sz);
+                                                               chunk_sz,
+                                                               &k,
+                                                               &bytes_cnt);
                                        if (errno) {
                                                perror("data verify msg_peek failed");
                                                goto out_errno;
@@ -812,7 +822,7 @@ static int sendmsg_test(struct sockmap_options *opt)
                                s.bytes_sent, sent_Bps, sent_Bps/giga,
                                s.bytes_recvd, recvd_Bps, recvd_Bps/giga,
                                peek_flag ? "(peek_msg)" : "");
-               if (err && txmsg_cork)
+               if (err && err != -EDATAINTEGRITY && txmsg_cork)
                        err = 0;
                exit(err ? 1 : 0);
        } else if (rxpid == -1) {