inetd: use change_identity().

libbb: shrink our internal initgroups().
httpd: remove stray 'else' and 'index_page = "index.html"'

function                                             old     new   delta
httpd_main                                           750     743      -7
inetd_main                                          2033    2011     -22
bb_internal_initgroups                               251     228     -23
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 0/3 up/down: 0/-52)             Total: -52 bytes

libbb/change_identity.c

@@ -35,7 +35,7 @@ void change_identity(const struct passwd *pw)
 {
 	if (initgroups(pw->pw_name, pw->pw_gid) == -1)
 		bb_perror_msg_and_die("can't set groups");
-	endgrent(); /* ?? */
+	endgrent(); /* helps to close a fd used internally by libc */
 	xsetgid(pw->pw_gid);
 	xsetuid(pw->pw_uid);
 }

libpwdgrp/pwd_grp.c

@@ -630,12 +630,11 @@ int initgroups(const char *user, gid_t gid)
 	char buff[PWD_BUFFER_SIZE];
 
 	rv = -1;
+	grfile = fopen(_PATH_GROUP, "r");
+	if (grfile != NULL) {
 
 		/* We alloc space for 8 gids at a time. */
-	group_list = (gid_t *) malloc(8*sizeof(gid_t *));
+		group_list = xmalloc(8 * sizeof(gid_t *));
-	if (group_list
-	 && ((grfile = fopen(_PATH_GROUP, "r")) != NULL)
-	) {
 		*group_list = gid;
 		num_groups = 1;
 
@@ -645,13 +644,8 @@ int initgroups(const char *user, gid_t gid)
 				for (m = group.gr_mem; *m; m++) {
 					if (!strcmp(*m, user)) {
 						if (!(num_groups & 7)) {
-							gid_t *tmp = (gid_t *)
+							gid_t *tmp = xrealloc(group_list,
-								realloc(group_list,
 									(num_groups+8) * sizeof(gid_t *));
-							if (!tmp) {
-								rv = -1;
-								goto DO_CLOSE;
-							}
 							group_list = tmp;
 						}
 						group_list[num_groups++] = group.gr_gid;
@@ -662,13 +656,10 @@ int initgroups(const char *user, gid_t gid)
 		}
 
 		rv = setgroups(num_groups, group_list);
-	DO_CLOSE:
+		free(group_list);
 		fclose(grfile);
 	}
 
-	/* group_list will be NULL if initial malloc failed, which may trigger
-	 * warnings from various malloc debuggers. */
-	free(group_list);
 	return rv;
 }
 
@@ -677,7 +668,7 @@ int putpwent(const struct passwd *__restrict p, FILE *__restrict f)
 	int rv = -1;
 
 	if (!p || !f) {
-		errno=EINVAL;
+		errno = EINVAL;
 	} else {
 		/* No extra thread locking is needed above what fprintf does. */
 		if (fprintf(f, "%s:%s:%lu:%lu:%s:%s:%s\n",
@@ -702,7 +693,7 @@ int putgrent(const struct group *__restrict p, FILE *__restrict f)
 	int rv = -1;
 
 	if (!p || !f) {				/* Sigh... glibc checks. */
-		errno=EINVAL;
+		errno = EINVAL;
 	} else {
 		if (fprintf(f, "%s:%s:%lu:",
 					p->gr_name, p->gr_passwd,

networking/httpd.c

@@ -2340,7 +2340,7 @@ int httpd_main(int argc ATTRIBUTE_UNUSED, char **argv)
 #if ENABLE_FEATURE_HTTPD_SETUID
 	if (opt & OPT_SETUID) {
 		if (!get_uidgid(&ugid, s_ugid, 1))
-			bb_error_msg_and_die("unrecognized user[:group] "
+			bb_error_msg_and_die("unknown user[:group] "
 						"name '%s'", s_ugid);
 	}
 #endif
@@ -2389,9 +2389,7 @@ int httpd_main(int argc ATTRIBUTE_UNUSED, char **argv)
 #if ENABLE_FEATURE_HTTPD_RELOAD_CONFIG_SIGHUP
 	if (!(opt & OPT_INETD))
 		sighup_handler(0);
-	else /* do not install HUP handler in inetd mode */
 #endif
-		index_page = "index.html";
 	parse_conf(default_path_httpd_conf, FIRST_PARSE);
 
 	xfunc_error_retval = 0;

networking/inetd.c

@@ -142,15 +142,15 @@
 /* Here's the scoop concerning the user[:group] feature:
  * 1) group is not specified:
  *      a) user = root: NO setuid() or setgid() is done
- *      b) other:       setgid(primary group as found in passwd)
+ *      b) other:       initgroups(name, primary group)
- *                      initgroups(name, primary group)
+ *                      setgid(primary group as found in passwd)
  *                      setuid()
  * 2) group is specified:
  *      a) user = root: setgid(specified group)
  *                      NO initgroups()
  *                      NO setuid()
- *      b) other:       setgid(specified group)
+ *      b) other:       initgroups(name, specified group)
- *                      initgroups(name, specified group)
+ *                      setgid(specified group)
  *                      setuid()
  */
 
@@ -1383,9 +1383,8 @@ int inetd_main(int argc ATTRIBUTE_UNUSED, char **argv)
 			if (pwd->pw_uid) {
 				if (sep->se_group)
 					pwd->pw_gid = grp->gr_gid;
-				xsetgid(pwd->pw_gid);
+				/* initgroups, setgid, setuid: */
-				initgroups(pwd->pw_name, pwd->pw_gid);
+				change_identity(pwd);
-				xsetuid(pwd->pw_uid);
 			} else if (sep->se_group) {
 				xsetgid(grp->gr_gid);
 				setgroups(1, &grp->gr_gid);