[libvirt] [PATCH 1/2] util: extend virGetUserID and virGetGroupID to support names and IDs

Marcelo Cerri mhcerri at linux.vnet.ibm.com
Mon Oct 8 13:18:40 UTC 2012


On Fri, Oct 05, 2012 at 11:52:23PM -0300, Marcelo Cerri wrote:
> This patch updates virGetUserID and virGetGroupID to be able to parse a
> user or group name in a similar way to coreutils' chown. This means that
> a numeric value with a leading plus sign is always parsed as an ID,
> otherwise the functions try to parse the input first as a user or group
> name and if this fails they try to parse it as an ID.
> ---
>  src/util/util.c | 87 ++++++++++++++++++++++++++++++++++++++++++++++++---------
>  1 file changed, 74 insertions(+), 13 deletions(-)
> 
> diff --git a/src/util/util.c b/src/util/util.c
> index 43fdaf1..694ed3d 100644
> --- a/src/util/util.c
> +++ b/src/util/util.c
> @@ -2495,9 +2495,11 @@ char *virGetGroupName(gid_t gid)
>      return virGetGroupEnt(gid);
>  }
> 
> -
> -int virGetUserID(const char *name,
> -                 uid_t *uid)
> +/* Search in the password database for a user id that matches the user name
> + * `name`. Returns 0 on success, -1 on a critical failure or 1 if name cannot
> + * be parsed.
> + */
> +static int virGetUserIDByName(const char *name, uid_t *uid)
>  {
>      char *strbuf;
>      struct passwd pwbuf;
> @@ -2530,11 +2532,10 @@ int virGetUserID(const char *name,
>          }
>      }
>      if (rc != 0 || pw == NULL) {
> -        virReportSystemError(rc,
> -                             _("Failed to find user record for name '%s'"),
> -                             name);
> +        VIR_DEBUG("Failed to find user record for user '%s' (error = %d)",
> +                  name, rc);
>          VIR_FREE(strbuf);
> -        return -1;
> +        return 1;
>      }
> 
>      *uid = pw->pw_uid;
> @@ -2544,9 +2545,41 @@ int virGetUserID(const char *name,
>      return 0;
>  }
> 
> +/* Try to match a user id based on `user`. The default behavior is to parse
> + * `user` first as a user name and then as a user id. However if `user`
> + * contains a leading '+', the rest of the string is always parsed as a uid.
> + *
> + * Returns 0 on success and -1 otherwise.
> + */
> +int virGetUserID(const char *user, uid_t *uid)
> +{
> +    unsigned int uint_uid;
> 
> -int virGetGroupID(const char *name,
> -                  gid_t *gid)
> +    if (*user == '+') {
> +        user++;
> +    } else {
> +        int rc = virGetUserIDByName(user, uid);
> +        if (rc <= 0)
> +            return rc;
> +    }
> +
> +    if (virStrToLong_ui(user, NULL, 10, &uint_uid) < 0 ||
> +        ((uid_t) uint_uid) != uint_uid) {
> +        virReportError(VIR_ERR_INVALID_ARG, _("Failed to parse user '%s'"),
> +                       user);
> +        return -1;
> +    }
> +
> +    *uid = uint_uid;
> +
> +    return 0;
> +}
> +
> +/* Search in the group database for a group id that matches the group name
> + * `name`. Returns 0 on success, -1 on a critical failure or 1 if name cannot
> + * be parsed.
> + */
> +static int virGetGroupIDByName(const char *name, gid_t *gid)
>  {
>      char *strbuf;
>      struct group grbuf;
> @@ -2579,11 +2612,10 @@ int virGetGroupID(const char *name,
>          }
>      }
>      if (rc != 0 || gr == NULL) {
> -        virReportSystemError(rc,
> -                             _("Failed to find group record for name '%s'"),
> -                             name);
> +        VIR_DEBUG("Failed to find group record for group '%s' (error = %d)",
> +                  name, rc);
>          VIR_FREE(strbuf);
> -        return -1;
> +        return 1;
>      }
> 
>      *gid = gr->gr_gid;
> @@ -2593,6 +2625,35 @@ int virGetGroupID(const char *name,
>      return 0;
>  }
> 
> +/* Try to match a group id based on `group`. The default behavior is to parse
> + * `group` first as a group name and then as a group id. However if `group`
> + * contains a leading '+', the rest of the string is always parsed as a guid.
> + *
> + * Returns 0 on success and -1 otherwise.
> + */
> +int virGetGroupID(const char *group, gid_t *gid)
> +{
> +    unsigned int uint_gid;
> +
> +    if (*group == '+') {
> +        group++;
> +    } else {
> +        int rc = virGetGroupIDByName(group, gid);
> +        if (rc <= 0)
> +            return rc;
> +    }
> +
> +    if (virStrToLong_ui(group, NULL, 10, &uint_gid) < 0 ||
> +        ((gid_t) uint_gid) != uint_gid) {
> +        virReportError(VIR_ERR_INVALID_ARG, _("Failed to parse user '%s'"),

Hmmm.. There's a copy-and-paste problem here. It should be 'group'
instead of 'user'.

I will wait to check if any other fixes will be needed and include it in
a next version of this series.

> +                       group);
> +        return -1;
> +    }
> +
> +    *gid = uint_gid;
> +
> +    return 0;
> +}
> 
>  /* Set the real and effective uid and gid to the given values, and call
>   * initgroups so that the process has all the assumed group membership of
> -- 
> 1.7.12
> 




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