Implement getgrgid_r and getgrnam_r. Rework group handling code to be fully

reentrant, since there was still a shared static value.  indent stuff,

1 files changed, 114 insertions, 0 deletions

diff --git a/libc/pwd_grp/__getgrent_r.c b/libc/pwd_grp/__getgrent_r.c
new file mode 100644
index 000000000..69559bdb1
--- /dev/null
+++ b/libc/pwd_grp/__getgrent_r.c
@@ -0,0 +1,114 @@
+/* vi: set sw=4 ts=4: */
+/*
+ * __getgrent.c - This file is part of the libc-8086/grp package for ELKS,
+ * Copyright (C) 1995, 1996 Nat Friedman <ndf@linux.mit.edu>.
+ * Copyright (C) 2001-2003 Erik Andersen <andersee@debian.org>
+ * 
+ *  This library is free software; you can redistribute it and/or
+ *  modify it under the terms of the GNU Library General Public
+ *  License as published by the Free Software Foundation; either
+ *  version 2 of the License, or (at your option) any later version.
+ *
+ *  This library is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ *  Library General Public License for more details.
+ *
+ *  You should have received a copy of the GNU Library General Public
+ *  License along with this library; if not, write to the Free
+ *  Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ *
+ */
+
+#include <features.h>
+#include <unistd.h>
+#include <stdlib.h>
+#include <string.h>
+#include <errno.h>
+#include "config.h"
+
+
+/*
+ * This is the core group-file read function.  It behaves exactly like
+ * getgrent() except that it is passed a file descriptor.  getgrent()
+ * is just a wrapper for this function.
+ */
+int __getgrent_r (struct group *__restrict group, 
+	char *__restrict line_buff, size_t buflen, int grp_fd)
+{
+	char *endptr, *field_begin, **members;
+	int i, line_len, member_num = 0;
+
+
+	if (buflen<GRP_BUFFER_SIZE) {
+		return ERANGE;
+	}
+
+	/* We use the restart label to handle malformatted lines */
+restart:
+	/* Read the group line into the buffer for processing */
+	if ((line_len = read(grp_fd, line_buff, buflen)) <= 0) {
+		return EIO;
+	}
+	field_begin = strchr(line_buff, '\n');
+	if (field_begin != NULL)
+		lseek(grp_fd, (long) (1 + field_begin - (line_buff + line_len)), SEEK_CUR);
+	else {
+		/* The line is too long - skip it. :-\ */
+		do {
+			if ((line_len = read(grp_fd, line_buff, buflen)) <= 0) {
+				return EIO;
+			}
+		} while (!(field_begin = strchr(line_buff, '\n')));
+		lseek(grp_fd, (long) (field_begin - line_buff) - line_len + 1, SEEK_CUR);
+		goto restart;
+	}
+	if (*line_buff == '#' || *line_buff == ' ' || *line_buff == '\n' || *line_buff == '\t')
+		goto restart;
+	*field_begin = '\0';
+
+	/* We've read the line; now parse it. */
+	field_begin = line_buff;
+	for (i = 0; i < 3; i++) {
+		switch (i) {
+			case 0:
+				group->gr_name = field_begin;
+				break;
+			case 1:
+				group->gr_passwd = field_begin;
+				break;
+			case 2:
+				group->gr_gid = (__gid_t) strtoul(field_begin, &endptr, 10);
+				if (*endptr != ':')
+					goto restart;
+				break;
+		}
+		if (i < 3) {
+			field_begin = strchr(field_begin, ':');
+			if (field_begin == NULL)
+				break;
+			*field_begin++ = '\0';
+		}
+	}
+
+	members = (char **) malloc(sizeof(char *));
+	if (members==NULL) {
+		return ENOMEM;
+	}
+	while(field_begin && strlen(field_begin)) {
+		members[member_num++] = field_begin;
+		members = (char **) realloc(members, (member_num + 1) * sizeof(char *));
+		if (members==NULL) {
+			return ENOMEM;
+		}
+		endptr = strchr(field_begin, ',');
+		if (endptr == NULL) {
+			/* Final entry */
+			break;
+		}
+		*field_begin++ = '\0';
+	}
+	members[member_num] = NULL;
+	group->gr_mem = members;
+	return 0;
+}