From: Matthew Harm Bekkema <id@mbekkema.name>
Date: Wed, 15 Apr 2020 12:49:54 +0000 (+1000)
Subject: lib/pwdutils: add xgetgrnam
X-Git-Tag: v2.36-rc1~140^2~1
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=dc96ca29d872a611801bdfd671c43c10c045cd3a;p=thirdparty%2Futil-linux.git

lib/pwdutils: add xgetgrnam

Signed-off-by: Matthew Harm Bekkema <id@mbekkema.name>
---

diff --git a/include/pwdutils.h b/include/pwdutils.h
index bea46e57e3..b58268d775 100644
--- a/include/pwdutils.h
+++ b/include/pwdutils.h
@@ -3,8 +3,10 @@
 
 #include <sys/types.h>
 #include <pwd.h>
+#include <grp.h>
 
 extern struct passwd *xgetpwnam(const char *username, char **pwdbuf);
+extern struct group *xgetgrnam(const char *groupname, char **grpbuf);
 extern struct passwd *xgetpwuid(uid_t uid, char **pwdbuf);
 extern char *xgetlogin(void);
 
diff --git a/lib/pwdutils.c b/lib/pwdutils.c
index d54458d65d..d5f4d2e232 100644
--- a/lib/pwdutils.c
+++ b/lib/pwdutils.c
@@ -36,6 +36,38 @@ failed:
 	return NULL;
 }
 
+/* Returns allocated group and allocated grpbuf to store group strings
+ * fields. In case of error returns NULL and set errno, for unknown group set
+ * errno to EINVAL
+ */
+struct group *xgetgrnam(const char *groupname, char **grpbuf)
+{
+	struct group *grp = NULL, *res = NULL;
+	int rc;
+
+	if (!grpbuf || !groupname)
+		return NULL;
+
+	*grpbuf = xmalloc(UL_GETPW_BUFSIZ);
+	grp = xcalloc(1, sizeof(struct group));
+
+	errno = 0;
+	rc = getgrnam_r(groupname, grp, *grpbuf, UL_GETPW_BUFSIZ, &res);
+	if (rc != 0) {
+		errno = rc;
+		goto failed;
+	}
+	if (!res) {
+		errno = EINVAL;
+		goto failed;
+	}
+	return grp;
+failed:
+	free(grp);
+	free(*grpbuf);
+	return NULL;
+}
+
 struct passwd *xgetpwuid(uid_t uid, char **pwdbuf)
 {
 	struct passwd *pwd = NULL, *res = NULL;