bpf: sockmap sample, add data verification option

To verify data is not being dropped or corrupted this adds an option
to verify test-patterns on recv.

Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>

samples/sockmap/sockmap_user.c

@@ -68,6 +68,7 @@ static const struct option long_options[] = {
 	{"iov_count",	required_argument,	NULL, 'i' },
 	{"length",	required_argument,	NULL, 'l' },
 	{"test",	required_argument,	NULL, 't' },
+	{"data_test",   no_argument,		NULL, 'd' },
 	{"txmsg",		no_argument,	&txmsg_pass,  1  },
 	{"txmsg_noisy",		no_argument,	&txmsg_noisy, 1  },
 	{"txmsg_redir",		no_argument,	&txmsg_redir, 1  },
@@ -208,45 +209,49 @@ struct msg_stats {
 static int msg_loop_sendpage(int fd, int iov_length, int cnt,
 			     struct msg_stats *s)
 {
-	off_t offset = 0;
+	unsigned char k = 0;
 	FILE *file;
 	int i, fp;
 
 	file = fopen(".sendpage_tst.tmp", "w+");
-	fseek(file, iov_length * cnt, SEEK_CUR);
+	for (i = 0; i < iov_length * cnt; i++, k++)
-	fprintf(file, "A");
+		fwrite(&k, sizeof(char), 1, file);
+	fflush(file);
 	fseek(file, 0, SEEK_SET);
+	fclose(file);
 
-	fp = fileno(file);
+	fp = open(".sendpage_tst.tmp", O_RDONLY);
 	clock_gettime(CLOCK_MONOTONIC, &s->start);
 	for (i = 0; i < cnt; i++) {
-		int sent = sendfile(fd, fp, &offset, iov_length);
+		int sent = sendfile(fd, fp, NULL, iov_length);
 
 		if (sent < 0) {
 			perror("send loop error:");
-			fclose(file);
+			close(fp);
 			return sent;
 		}
 		s->bytes_sent += sent;
 	}
 	clock_gettime(CLOCK_MONOTONIC, &s->end);
-	fclose(file);
+	close(fp);
 	return 0;
 }
 
 static int msg_loop(int fd, int iov_count, int iov_length, int cnt,
-		    struct msg_stats *s, bool tx)
+		    struct msg_stats *s, bool tx, bool data_test)
 {
 	struct msghdr msg = {0};
 	int err, i, flags = MSG_NOSIGNAL;
 	struct iovec *iov;
+	unsigned char k;
 
 	iov = calloc(iov_count, sizeof(struct iovec));
 	if (!iov)
 		return errno;
 
+	k = 0;
 	for (i = 0; i < iov_count; i++) {
-		char *d = calloc(iov_length, sizeof(char));
+		unsigned char *d = calloc(iov_length, sizeof(char));
 
 		if (!d) {
 			fprintf(stderr, "iov_count %i/%i OOM\n", i, iov_count);
@@ -254,10 +259,18 @@ static int msg_loop(int fd, int iov_count, int iov_length, int cnt,
 		}
 		iov[i].iov_base = d;
 		iov[i].iov_len = iov_length;
+
+		if (data_test && tx) {
+			int j;
+
+			for (j = 0; j < iov_length; j++)
+				d[j] = k++;
+		}
 	}
 
 	msg.msg_iov = iov;
 	msg.msg_iovlen = iov_count;
+	k = 0;
 
 	if (tx) {
 		clock_gettime(CLOCK_MONOTONIC, &s->start);
@@ -311,6 +324,26 @@ static int msg_loop(int fd, int iov_count, int iov_length, int cnt,
 			}
 
 			s->bytes_recvd += recv;
+
+			if (data_test) {
+				int j;
+
+				for (i = 0; i < msg.msg_iovlen; i++) {
+					unsigned char *d = iov[i].iov_base;
+
+					for (j = 0;
+					     j < iov[i].iov_len && recv; j++) {
+						if (d[j] != k++) {
+							errno = -EIO;
+							fprintf(stderr,
+								"detected data corruption @iov[%i]:%i %02x != %02x, %02x ?= %02x\n",
+								i, j, d[j], k - 1, d[j+1], k + 1);
+							goto out_errno;
+						}
+						recv--;
+					}
+				}
+			}
 		}
 		clock_gettime(CLOCK_MONOTONIC, &s->end);
 	}
@@ -338,8 +371,15 @@ static inline float recvdBps(struct msg_stats s)
 	return s.bytes_recvd / (s.end.tv_sec - s.start.tv_sec);
 }
 
+struct sockmap_options {
+	int verbose;
+	bool base;
+	bool sendpage;
+	bool data_test;
+};
+
 static int sendmsg_test(int iov_count, int iov_buf, int cnt,
-			int verbose, bool base, bool sendpage)
+			struct sockmap_options *opt)
 {
 	float sent_Bps = 0, recvd_Bps = 0;
 	int rx_fd, txpid, rxpid, err = 0;
@@ -348,16 +388,17 @@ static int sendmsg_test(int iov_count, int iov_buf, int cnt,
 
 	errno = 0;
 
-	if (base)
+	if (opt->base)
 		rx_fd = p1;
 	else
 		rx_fd = p2;
 
 	rxpid = fork();
 	if (rxpid == 0) {
-		if (sendpage)
+		if (opt->sendpage)
 			iov_count = 1;
-		err = msg_loop(rx_fd, iov_count, iov_buf, cnt, &s, false);
+		err = msg_loop(rx_fd, iov_count, iov_buf,
+			       cnt, &s, false, opt->data_test);
 		if (err)
 			fprintf(stderr,
 				"msg_loop_rx: iov_count %i iov_buf %i cnt %i err %i\n",
@@ -380,10 +421,11 @@ static int sendmsg_test(int iov_count, int iov_buf, int cnt,
 
 	txpid = fork();
 	if (txpid == 0) {
-		if (sendpage)
+		if (opt->sendpage)
 			err = msg_loop_sendpage(c1, iov_buf, cnt, &s);
 		else
-			err = msg_loop(c1, iov_count, iov_buf, cnt, &s, true);
+			err = msg_loop(c1, iov_count, iov_buf,
+				       cnt, &s, true, opt->data_test);
 
 		if (err)
 			fprintf(stderr,
@@ -409,7 +451,7 @@ static int sendmsg_test(int iov_count, int iov_buf, int cnt,
 	return err;
 }
 
-static int forever_ping_pong(int rate, int verbose)
+static int forever_ping_pong(int rate, struct sockmap_options *opt)
 {
 	struct timeval timeout;
 	char buf[1024] = {0};
@@ -474,7 +516,7 @@ static int forever_ping_pong(int rate, int verbose)
 		if (rate)
 			sleep(rate);
 
-		if (verbose) {
+		if (opt->verbose) {
 			printf(".");
 			fflush(stdout);
 
@@ -494,13 +536,14 @@ enum {
 
 int main(int argc, char **argv)
 {
-	int iov_count = 1, length = 1024, rate = 1, verbose = 0, tx_prog_fd;
+	int iov_count = 1, length = 1024, rate = 1, tx_prog_fd;
 	struct rlimit r = {10 * 1024 * 1024, RLIM_INFINITY};
 	int opt, longindex, err, cg_fd = 0;
+	struct sockmap_options options = {0};
 	int test = PING_PONG;
 	char filename[256];
 
-	while ((opt = getopt_long(argc, argv, ":hvc:r:i:l:t:",
+	while ((opt = getopt_long(argc, argv, ":dhvc:r:i:l:t:",
 				  long_options, &longindex)) != -1) {
 		switch (opt) {
 		/* Cgroup configuration */
@@ -517,7 +560,7 @@ int main(int argc, char **argv)
 			rate = atoi(optarg);
 			break;
 		case 'v':
-			verbose = 1;
+			options.verbose = 1;
 			break;
 		case 'i':
 			iov_count = atoi(optarg);
@@ -525,6 +568,9 @@ int main(int argc, char **argv)
 		case 'l':
 			length = atoi(optarg);
 			break;
+		case 'd':
+			options.data_test = true;
+			break;
 		case 't':
 			if (strcmp(optarg, "ping") == 0) {
 				test = PING_PONG;
@@ -655,20 +701,24 @@ run:
 		}
 	}
 	if (test == PING_PONG)
-		err = forever_ping_pong(rate, verbose);
+		err = forever_ping_pong(rate, &options);
-	else if (test == SENDMSG)
+	else if (test == SENDMSG) {
-		err = sendmsg_test(iov_count, length, rate,
+		options.base = false;
-				   verbose, false, false);
+		options.sendpage = false;
-	else if (test == SENDPAGE)
+		err = sendmsg_test(iov_count, length, rate, &options);
-		err = sendmsg_test(iov_count, length, rate,
+	} else if (test == SENDPAGE) {
-				   verbose, false, true);
+		options.base = false;
-	else if (test == BASE)
+		options.sendpage = true;
-		err = sendmsg_test(iov_count, length, rate,
+		err = sendmsg_test(iov_count, length, rate, &options);
-				   verbose, true, false);
+	} else if (test == BASE) {
-	else if (test == BASE_SENDPAGE)
+		options.base = true;
-		err = sendmsg_test(iov_count, length, rate,
+		options.sendpage = false;
-				   verbose, true, true);
+		err = sendmsg_test(iov_count, length, rate, &options);
-	else
+	} else if (test == BASE_SENDPAGE) {
+		options.base = true;
+		options.sendpage = true;
+		err = sendmsg_test(iov_count, length, rate, &options);
+	} else
 		fprintf(stderr, "unknown test\n");
 out:
 	bpf_prog_detach2(prog_fd[2], cg_fd, BPF_CGROUP_SOCK_OPS);