Re: [Qemu-devel] [PATCH 21/24] util/cutils: Let qemu_strtosz*() optionally reject trailing crap

["Dr. David Alan Gilbert" <dgilbert@redhat.com>]

* Markus Armbruster (armbru@redhat.com) wrote:
> Change the qemu_strtosz() & friends to return -EINVAL when @endptr is
> null and the conversion doesn't consume the string completely.
> Matches how qemu_strtol() & friends work.
> 
> Only test_qemu_strtosz_simple() passes a null @endptr.  No functional
> change there, because its conversion consumes the string.
> 
> Simplify callers that use @endptr only to fail when it doesn't point
> to '\0' to pass a null @endptr instead.
> 
> Cc: Dr. David Alan Gilbert <dgilbert@redhat.com>
> Cc: Eduardo Habkost <ehabkost@redhat.com> (maintainer:X86)
> Cc: Kevin Wolf <kwolf@redhat.com> (supporter:Block layer core)
> Cc: Max Reitz <mreitz@redhat.com> (supporter:Block layer core)
> Cc: qemu-block@nongnu.org (open list:Block layer core)
> Signed-off-by: Markus Armbruster <armbru@redhat.com>

Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>

(end and endptr are horribly confusing names in do_strtosz)

> ---
>  hmp.c               |  6 ++----
>  hw/misc/ivshmem.c   |  6 ++----
>  qapi/opts-visitor.c |  5 ++---
>  qemu-img.c          |  7 +------
>  qemu-io-cmds.c      |  7 +------
>  target/i386/cpu.c   |  5 ++---
>  tests/test-cutils.c |  6 ++++++
>  util/cutils.c       | 14 +++++++++-----
>  8 files changed, 25 insertions(+), 31 deletions(-)
> 
> diff --git a/hmp.c b/hmp.c
> index 6d0d05b..0eb5b6d 100644
> --- a/hmp.c
> +++ b/hmp.c
> @@ -1340,7 +1340,6 @@ void hmp_migrate_set_parameter(Monitor *mon, const QDict *qdict)
>      const char *valuestr = qdict_get_str(qdict, "value");
>      int64_t valuebw = 0;
>      long valueint = 0;
> -    char *endp;
>      Error *err = NULL;
>      bool use_int_value = false;
>      int i;
> @@ -1379,9 +1378,8 @@ void hmp_migrate_set_parameter(Monitor *mon, const QDict *qdict)
>                  break;
>              case MIGRATION_PARAMETER_MAX_BANDWIDTH:
>                  p.has_max_bandwidth = true;
> -                valuebw = qemu_strtosz_mebi(valuestr, &endp);
> -                if (valuebw < 0 || (size_t)valuebw != valuebw
> -                    || *endp != '\0') {
> +                valuebw = qemu_strtosz_mebi(valuestr, NULL);
> +                if (valuebw < 0 || (size_t)valuebw != valuebw) {
>                      error_setg(&err, "Invalid size %s", valuestr);
>                      goto cleanup;
>                  }
> diff --git a/hw/misc/ivshmem.c b/hw/misc/ivshmem.c
> index 382dd8b..f00cd75 100644
> --- a/hw/misc/ivshmem.c
> +++ b/hw/misc/ivshmem.c
> @@ -1267,10 +1267,8 @@ static void ivshmem_realize(PCIDevice *dev, Error **errp)
>      if (s->sizearg == NULL) {
>          s->legacy_size = 4 << 20; /* 4 MB default */
>      } else {
> -        char *end;
> -        int64_t size = qemu_strtosz_mebi(s->sizearg, &end);
> -        if (size < 0 || (size_t)size != size || *end != '\0'
> -            || !is_power_of_2(size)) {
> +        int64_t size = qemu_strtosz_mebi(s->sizearg, NULL);
> +        if (size < 0 || (size_t)size != size || !is_power_of_2(size)) {
>              error_setg(errp, "Invalid size %s", s->sizearg);
>              return;
>          }
> diff --git a/qapi/opts-visitor.c b/qapi/opts-visitor.c
> index 360d337..911a0ee 100644
> --- a/qapi/opts-visitor.c
> +++ b/qapi/opts-visitor.c
> @@ -482,15 +482,14 @@ opts_type_size(Visitor *v, const char *name, uint64_t *obj, Error **errp)
>      OptsVisitor *ov = to_ov(v);
>      const QemuOpt *opt;
>      int64_t val;
> -    char *endptr;
>  
>      opt = lookup_scalar(ov, name, errp);
>      if (!opt) {
>          return;
>      }
>  
> -    val = qemu_strtosz(opt->str ? opt->str : "", &endptr);
> -    if (val < 0 || *endptr) {
> +    val = qemu_strtosz(opt->str ? opt->str : "", NULL);
> +    if (val < 0) {
>          error_setg(errp, QERR_INVALID_PARAMETER_VALUE, opt->name,
>                     "a size value representible as a non-negative int64");
>          return;
> diff --git a/qemu-img.c b/qemu-img.c
> index 2a47966..adcb511 100644
> --- a/qemu-img.c
> +++ b/qemu-img.c
> @@ -370,14 +370,9 @@ static int add_old_style_options(const char *fmt, QemuOpts *opts,
>  
>  static int64_t cvtnum(const char *s)
>  {
> -    char *end;
>      int64_t ret;
>  
> -    ret = qemu_strtosz(s, &end);
> -    if (*end != '\0') {
> -        /* Detritus at the end of the string */
> -        return -EINVAL;
> -    }
> +    ret = qemu_strtosz(s, NULL);
>      return ret;
>  }
>  
> diff --git a/qemu-io-cmds.c b/qemu-io-cmds.c
> index 6b7a89c..417a4e0 100644
> --- a/qemu-io-cmds.c
> +++ b/qemu-io-cmds.c
> @@ -137,14 +137,9 @@ static char **breakline(char *input, int *count)
>  
>  static int64_t cvtnum(const char *s)
>  {
> -    char *end;
>      int64_t ret;
>  
> -    ret = qemu_strtosz(s, &end);
> -    if (*end != '\0') {
> -        /* Detritus at the end of the string */
> -        return -EINVAL;
> -    }
> +    ret = qemu_strtosz(s, NULL);
>      return ret;
>  }
>  
> diff --git a/target/i386/cpu.c b/target/i386/cpu.c
> index 3a8d72d..5cb0b4b 100644
> --- a/target/i386/cpu.c
> +++ b/target/i386/cpu.c
> @@ -2034,10 +2034,9 @@ static void x86_cpu_parse_featurestr(const char *typename, char *features,
>          /* Special case: */
>          if (!strcmp(name, "tsc-freq")) {
>              int64_t tsc_freq;
> -            char *err;
>  
> -            tsc_freq = qemu_strtosz_metric(val, &err);
> -            if (tsc_freq < 0 || *err) {
> +            tsc_freq = qemu_strtosz_metric(val, NULL);
> +            if (tsc_freq < 0) {
>                  error_setg(errp, "bad numerical value %s", val);
>                  return;
>              }
> diff --git a/tests/test-cutils.c b/tests/test-cutils.c
> index 585912b..07095e3 100644
> --- a/tests/test-cutils.c
> +++ b/tests/test-cutils.c
> @@ -1510,10 +1510,16 @@ static void test_qemu_strtosz_trailing(void)
>      g_assert_cmpint(res, ==, 123 * M_BYTE);
>      g_assert(endptr == str + 3);
>  
> +    res = qemu_strtosz(str, NULL);
> +    g_assert_cmpint(res, ==, -EINVAL);
> +
>      str = "1kiB";
>      res = qemu_strtosz(str, &endptr);
>      g_assert_cmpint(res, ==, 1024);
>      g_assert(endptr == str + 2);
> +
> +    res = qemu_strtosz(str, NULL);
> +    g_assert_cmpint(res, ==, -EINVAL);
>  }
>  
>  static void test_qemu_strtosz_erange(void)
> diff --git a/util/cutils.c b/util/cutils.c
> index 4a290ea..5c1bfe5 100644
> --- a/util/cutils.c
> +++ b/util/cutils.c
> @@ -208,7 +208,7 @@ static int64_t suffix_mul(char suffix, int64_t unit)
>  static int64_t do_strtosz(const char *nptr, char **end,
>                            const char default_suffix, int64_t unit)
>  {
> -    int64_t retval = -EINVAL;
> +    int64_t retval;
>      char *endptr;
>      unsigned char c;
>      int mul_required = 0;
> @@ -217,7 +217,8 @@ static int64_t do_strtosz(const char *nptr, char **end,
>      errno = 0;
>      val = strtod(nptr, &endptr);
>      if (isnan(val) || endptr == nptr || errno != 0) {
> -        goto fail;
> +        retval = -EINVAL;
> +        goto out;
>      }
>      fraction = modf(val, &integral);
>      if (fraction != 0) {
> @@ -232,17 +233,20 @@ static int64_t do_strtosz(const char *nptr, char **end,
>          assert(mul >= 0);
>      }
>      if (mul == 1 && mul_required) {
> -        goto fail;
> +        retval = -EINVAL;
> +        goto out;
>      }
>      if ((val * mul >= INT64_MAX) || val < 0) {
>          retval = -ERANGE;
> -        goto fail;
> +        goto out;
>      }
>      retval = val * mul;
>  
> -fail:
> +out:
>      if (end) {
>          *end = endptr;
> +    } else if (*endptr) {
> +        retval = -EINVAL;
>      }
>  
>      return retval;
> -- 
> 2.7.4
> 
--
Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK