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

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; +} +