nvme-fcloop: verify wwnn and wwpn format

The nvme host and target verify the wwnn and wwpn format via
nvme_fc_parse_traddr(). For instance, it is required that the length of
wwnn to be either 21 ("nn-0x") or 19 (nn-).

Add this verification to nvme-fcloop so that the input should always be in
hex and the length of input should always be 18.

Otherwise, the user may use e.g. 0x2 to create fcloop local port, while
0x0000000000000002 is required for nvme host and target. This makes the
requirement of format confusing.
Signed-off-by: Dongli Zhang <dongli.zhang@oracle.com>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: James Smart <james.smart@broadcom.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

drivers/nvme/target/fcloop.c

@@ -43,6 +43,17 @@ static const match_table_t opt_tokens = {
 	{ NVMF_OPT_ERR,		NULL		}
 };
 
+static int fcloop_verify_addr(substring_t *s)
+{
+	size_t blen = s->to - s->from + 1;
+
+	if (strnlen(s->from, blen) != NVME_FC_TRADDR_HEXNAMELEN + 2 ||
+	    strncmp(s->from, "0x", 2))
+		return -EINVAL;
+
+	return 0;
+}
+
 static int
 fcloop_parse_options(struct fcloop_ctrl_options *opts,
 		const char *buf)
@@ -64,14 +75,16 @@ fcloop_parse_options(struct fcloop_ctrl_options *opts,
 		opts->mask |= token;
 		switch (token) {
 		case NVMF_OPT_WWNN:
-			if (match_u64(args, &token64)) {
+			if (fcloop_verify_addr(args) ||
+			    match_u64(args, &token64)) {
 				ret = -EINVAL;
 				goto out_free_options;
 			}
 			opts->wwnn = token64;
 			break;
 		case NVMF_OPT_WWPN:
-			if (match_u64(args, &token64)) {
+			if (fcloop_verify_addr(args) ||
+			    match_u64(args, &token64)) {
 				ret = -EINVAL;
 				goto out_free_options;
 			}
@@ -92,14 +105,16 @@ fcloop_parse_options(struct fcloop_ctrl_options *opts,
 			opts->fcaddr = token;
 			break;
 		case NVMF_OPT_LPWWNN:
-			if (match_u64(args, &token64)) {
+			if (fcloop_verify_addr(args) ||
+			    match_u64(args, &token64)) {
 				ret = -EINVAL;
 				goto out_free_options;
 			}
 			opts->lpwwnn = token64;
 			break;
 		case NVMF_OPT_LPWWPN:
-			if (match_u64(args, &token64)) {
+			if (fcloop_verify_addr(args) ||
+			    match_u64(args, &token64)) {
 				ret = -EINVAL;
 				goto out_free_options;
 			}
@@ -141,14 +156,16 @@ fcloop_parse_nm_options(struct device *dev, u64 *nname, u64 *pname,
 		token = match_token(p, opt_tokens, args);
 		switch (token) {
 		case NVMF_OPT_WWNN:
-			if (match_u64(args, &token64)) {
+			if (fcloop_verify_addr(args) ||
+			    match_u64(args, &token64)) {
 				ret = -EINVAL;
 				goto out_free_options;
 			}
 			*nname = token64;
 			break;
 		case NVMF_OPT_WWPN:
-			if (match_u64(args, &token64)) {
+			if (fcloop_verify_addr(args) ||
+			    match_u64(args, &token64)) {
 				ret = -EINVAL;
 				goto out_free_options;
 			}