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Subject: Re: [PATCH 1/1] nvme-fcloop: verify wwnn and wwpn format
From:   Dongli Zhang <dongli.zhang@oracle.com>
To:     linux-nvme@lists.infradead.org, james.smart@broadcom.com
Cc:     sagi@grimberg.me, linux-kernel@vger.kernel.org,
        chaitanya.kulkarni@wdc.com, hch@lst.de
References: <20200526042118.17836-1-dongli.zhang@oracle.com>
Message-ID: <38a2cfb9-df2a-c5cb-6797-2b96ef049c7c@oracle.com>
Date:   Wed, 3 Jun 2020 23:43:47 -0700
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May I get feedback for this?

For the first time I use fcloop, I set:

# echo "wwnn=0x3,wwpn=0x1" > /sys/class/fcloop/ctl/add_target_port

However, I would not be able to move forward if I use "0x3" or "0x1" for nvme-fc
target or host further. Instead, the address and port should be
0x0000000000000003 and 0x0000000000000001.

This patch would sync the requirements of input format for nvme-fc and
nvme-fcloop, unless this would break existing test suite (e.g., blktest).

Thank you very much!

Dongli Zhang

On 5/25/20 9:21 PM, Dongli Zhang wrote:
> 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>
> ---
>  drivers/nvme/target/fcloop.c | 29 +++++++++++++++++++++++------
>  1 file changed, 23 insertions(+), 6 deletions(-)
> 
> diff --git a/drivers/nvme/target/fcloop.c b/drivers/nvme/target/fcloop.c
> index f69ce66e2d44..14124e6d4bf2 100644
> --- a/drivers/nvme/target/fcloop.c
> +++ b/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;
>  			}
>