Re: [Qemu-devel] [PATCH v2 07/22] qemu-nbd: Avoid strtol open-coding

["Richard W.M. Jones" <rjones@redhat.com>]

On Sat, Dec 15, 2018 at 07:53:09AM -0600, Eric Blake wrote:
> Our copy-and-pasted open-coding of strtol handling forgot to
> handle overflow conditions.  Use qemu_strto*() instead.
> 
> In the case of --partition, since we insist on a user-supplied
> partition to be non-zero, we can use 0 rather than -1 for our
> initial value to distinguish when a partition is not being
> served, for slightly more optimal code.
> 
> The error messages for out-of-bounds values are less specific,
> but should not be a terrible loss in quality.
> 
> Signed-off-by: Eric Blake <eblake@redhat.com>
> 
> ---
> v2: Retitle, catch more uses of strtol
> [Hmm - this depends on int64_t and off_t being compatible; if they
> aren't that way on all platforms, I'll need a temporary variable]
> ---
>  qemu-nbd.c | 33 ++++++++++-----------------------
>  1 file changed, 10 insertions(+), 23 deletions(-)
> 
> diff --git a/qemu-nbd.c b/qemu-nbd.c
> index 2807e132396..e3f739671b5 100644
> --- a/qemu-nbd.c
> +++ b/qemu-nbd.c
> @@ -544,9 +544,8 @@ int main(int argc, char **argv)
>      };
>      int ch;
>      int opt_ind = 0;
> -    char *end;
>      int flags = BDRV_O_RDWR;
> -    int partition = -1;
> +    int partition = 0;
>      int ret = 0;
>      bool seen_cache = false;
>      bool seen_discard = false;
> @@ -657,13 +656,9 @@ int main(int argc, char **argv)
>              port = optarg;
>              break;
>          case 'o':
> -                dev_offset = strtoll (optarg, &end, 0);
> -            if (*end) {
> -                error_report("Invalid offset `%s'", optarg);
> -                exit(EXIT_FAILURE);
> -            }
> -            if (dev_offset < 0) {
> -                error_report("Offset must be positive `%s'", optarg);
> +            if (qemu_strtoi64(optarg, NULL, 0, &dev_offset) < 0 ||
> +                dev_offset < 0) {
> +                error_report("Invalid offset '%s'", optarg);
>                  exit(EXIT_FAILURE);
>              }
>              break;
> @@ -685,13 +680,9 @@ int main(int argc, char **argv)
>              flags &= ~BDRV_O_RDWR;
>              break;
>          case 'P':
> -            partition = strtol(optarg, &end, 0);
> -            if (*end) {
> -                error_report("Invalid partition `%s'", optarg);
> -                exit(EXIT_FAILURE);
> -            }
> -            if (partition < 1 || partition > 8) {
> -                error_report("Invalid partition %d", partition);
> +            if (qemu_strtoi(optarg, NULL, 0, &partition) < 0 ||
> +                partition < 1 || partition > 8) {
> +                error_report("Invalid partition '%s'", optarg);
>                  exit(EXIT_FAILURE);
>              }
>              break;
> @@ -709,15 +700,11 @@ int main(int argc, char **argv)
>              device = optarg;
>              break;
>          case 'e':
> -            shared = strtol(optarg, &end, 0);
> -            if (*end) {
> +            if (qemu_strtoi(optarg, NULL, 0, &shared) < 0 ||
> +                shared < 1) {
>                  error_report("Invalid shared device number '%s'", optarg);
>                  exit(EXIT_FAILURE);
>              }
> -            if (shared < 1) {
> -                error_report("Shared device number must be greater than 0");
> -                exit(EXIT_FAILURE);
> -            }
>              break;
>          case 'f':
>              fmt = optarg;
> @@ -1006,7 +993,7 @@ int main(int argc, char **argv)
>      }
>      fd_size -= dev_offset;
> 
> -    if (partition != -1) {
> +    if (partition) {
>          ret = find_partition(blk, partition, &dev_offset, &fd_size);
>          if (ret < 0) {
>              error_report("Could not find partition %d: %s", partition,

Using qemu_strtoi has made the patch slightly bigger that last time
but is still a simplification, so:

Reviewed-by: Richard W.M. Jones <rjones@redhat.com>

Rich.

-- 
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