setup: grouprename.c (NEW) - shameles ripoff of joinpasswd.c
baggins
baggins at pld-linux.org
Mon Jan 26 19:26:41 CET 2009
Author: baggins Date: Mon Jan 26 18:26:41 2009 GMT
Module: setup Tag: HEAD
---- Log message:
- shameles ripoff of joinpasswd.c
---- Files affected:
setup:
grouprename.c (NONE -> 1.1) (NEW)
---- Diffs:
================================================================
Index: setup/grouprename.c
diff -u /dev/null setup/grouprename.c:1.1
--- /dev/null Mon Jan 26 19:26:41 2009
+++ setup/grouprename.c Mon Jan 26 19:26:35 2009
@@ -0,0 +1,342 @@
+/*
+ * $Id$
+ *
+ * Copyright (c) 2001 Michal Moskal <malekith at pld-linux.org>.
+ * Copyright (c) 2009 Jan Rękorajski <baggins at pld-linux.org>.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ * 3. All advertising materials mentioning features or use of this software
+ * must display the following acknowledgement:
+ * This product includes software developed by Michal Moskal.
+ * 4. Neither the name of the author nor the names of any co-contributors
+ * may be used to endorse or promote products derived from this software
+ * without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY MICHAL MOSKAL AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ *
+ *
+ * USAGE: grouprename old-name new-name
+ *
+ * Change the name of a group from old-name to new-name,
+ * It is usable as part of setup package, during upgrade in case a group name
+ * has to change. If new-name is already found in system database or old-name
+ * is not found, nothing changes,. UIDs/GIDs are *not* checked anyhow.
+ *
+ * Written for PLD Linux (http://www.pld-linux.org/) setup package.
+ *
+ * Compilation against uClibc:
+ * UCROOT=/usr/lib/bootdisk/usr
+ * gcc -I$UCROOT/include -nostdlib -O2 grouprename.c $UCROOT/lib/crt0.o \
+ * $UCROOT/lib/libc.a -lgcc -o grouprename
+ * strip -R .comment -R .note grouprename
+ *
+ * Shamelss ripoff of the joinpasswd.c program
+ *
+ */
+
+#include <sys/types.h>
+#include <sys/mman.h>
+#include <sys/stat.h>
+#include <unistd.h>
+#include <fcntl.h>
+#include <stdlib.h>
+#include <stdio.h> // for rename(2)
+#include <string.h>
+#include <signal.h>
+
+#define FILE3 "/etc/group"
+#define FILE4 "/etc/gshadow"
+
+/* #define OLD_LOCK */
+
+#define LOCK_FILE "/etc/.pwd.lock"
+
+/* maybe "-" or sth? */
+#define BACKUP ".old"
+
+/* #define SILENT */
+
+void eputs(const char *msg)
+{
+ write(2, msg, strlen(msg));
+}
+
+void fatal(const char *msg)
+{
+ eputs(msg);
+ eputs("\n");
+ exit(1);
+}
+
+char *map_file(const char *name, int *sz, int *mfd)
+{
+ int fd;
+ void *ptr;
+ struct stat st;
+
+ fd = open(name, O_RDONLY);
+ if (fd == -1)
+ return NULL;
+ *mfd = fd;
+ fstat(fd, &st);
+ *sz = st.st_size;
+ ptr = mmap(NULL, st.st_size, PROT_READ, MAP_PRIVATE, fd, 0);
+ if (ptr == MAP_FAILED)
+ return NULL;
+
+ return ptr;
+}
+
+int exist(char *id, int id_len, char *ptr, int sz)
+{
+ int i;
+
+ for (i = 0; i < sz; ) {
+ if (sz - i > id_len && memcmp(id, ptr, id_len) == 0)
+ return 1;
+ while (i < sz && ptr[i] != '\n')
+ i++;
+ i++;
+ }
+
+ return 0;
+}
+
+void itoa(char *buf, long i)
+{
+ char tmp[32];
+ char *p;
+
+ if (i < 0) {
+ strcpy(buf, "-");
+ buf++;
+ i = -i;
+ }
+ if (i == 0) {
+ strcpy(buf, "0");
+ return;
+ }
+ for (p = tmp; i; i /= 10)
+ *p++ = (i % 10) + '0';
+ while (p > tmp)
+ *buf++ = *--p;
+ *buf = 0;
+}
+
+#ifndef OLD_LOCK
+int lock_fd = -1;
+void noop(int x)
+{
+ (void)x;
+}
+#endif
+
+int try_lock(const char *name)
+{
+#ifdef OLD_LOCK
+ char file[strlen(name) + 32], lock[strlen(name) + 32];
+ char buf[32];
+ int fd;
+ long pid;
+
+ strcpy(lock, name);
+ strcpy(file, name);
+ strcat(lock, ".lock");
+ itoa(buf, (long)getpid());
+ strcat(file, ".");
+ strcat(file, buf);
+
+ fd = open(file, O_WRONLY|O_CREAT|O_EXCL|O_TRUNC, 0600);
+ if (fd < 0)
+ return -1;
+ write(fd, buf, strlen(buf));
+ close(fd);
+
+ if (link(file, lock) == 0) {
+ unlink(file);
+ return 0;
+ }
+
+ fd = open(lock, O_RDONLY);
+ if (fd < 0)
+ goto oops;
+ memset(buf, 0, sizeof(buf));
+ read(fd, buf, sizeof(buf));
+ pid = atol(buf);
+ if (pid == 0 || kill(pid, 0) != 0) {
+ /* stale lock */
+ unlink(file);
+ unlink(lock);
+ /* try again */
+ return try_lock(name);
+ }
+
+oops:
+ unlink(file);
+ return -1;
+#else
+ struct flock fl;
+
+ if (lock_fd != -1)
+ return -1;
+ lock_fd = open(LOCK_FILE, O_RDWR|O_CREAT, 0600);
+ if (lock_fd == -1)
+ return -1;
+ signal(SIGALRM, noop);
+ alarm(15);
+ memset(&fl, 0, sizeof(fl));
+ fl.l_type = F_WRLCK;
+ fl.l_whence = SEEK_SET;
+ if (fcntl(lock_fd, F_SETLKW, &fl) != 0) {
+ alarm(0);
+ close(lock_fd);
+ lock_fd = -1;
+ return -1;
+ }
+ alarm(0);
+
+ return 0;
+#endif
+}
+
+void unlock(const char *name)
+{
+#ifdef OLD_LOCK
+ char lock[strlen(name) + 32];
+
+ strcpy(lock, name);
+ strcat(lock, ".lock");
+ unlink(lock);
+#else
+ if (lock_fd != -1)
+ close(lock_fd);
+ lock_fd = -1;
+#endif
+}
+
+void lock(const char *name)
+{
+ int n;
+
+ n = 5;
+ while (n--) {
+ if (try_lock(name) == 0)
+ return;
+ eputs("waiting for lock...\n");
+ sleep(1);
+ }
+ fatal("cannot get lock");
+}
+
+int join(const char *oldgr, const char *newgr, const char *name, const char *backup)
+{
+ char *old, *id;
+ int i, fd, mfd;
+ int sz;
+
+// lock(name);
+ old = map_file(name, &sz, &mfd);
+ if (old == NULL)
+ fatal("cannot mmap old");
+
+ fd = open(backup, O_WRONLY|O_CREAT|O_TRUNC, 0600);
+ if (fd < 0)
+ fatal("cannot make backup");
+ write(fd, old, sz);
+ close(fd);
+
+ munmap(old, sz);
+ close(mfd);
+
+#ifndef SILENT
+ eputs("working on `");
+ eputs(name);
+ eputs("'\n");
+#endif /* SILENT */
+
+ old = map_file(backup, &sz, &mfd);
+ if (old == NULL)
+ fatal("cannot mmap backup");
+
+ fd = open(name, O_CREAT|O_WRONLY|O_TRUNC, 0644);
+ if (fd < 0)
+ fatal("cannot open new file");
+
+ for (i = 0; i < sz; ) {
+ id = old + i;
+ while (i < sz && old[i] != ':' && old[i] != '\n')
+ i++;
+ if (i < sz && old[i] == ':') {
+ int id_len, line_len;
+ char *rem = old + i;
+
+ id_len = i - (id - old);
+ while (i < sz && old[i] != '\n')
+ i++;
+ if (i < sz)
+ i++;
+ line_len = i - (rem - old);
+
+ if (id_len == strlen(oldgr) &&
+ memcmp(id, oldgr, id_len) == 0) {
+#ifndef SILENT
+ eputs(oldgr);
+ eputs(": ranaming to `");
+ eputs(newgr);
+ eputs("'\n");
+#endif /* SILENT */
+ write(fd, newgr, strlen(newgr));
+ } else
+ write(fd, id, id_len);
+ write(fd, rem, line_len);
+ } else if (i < sz)
+ i++;
+ }
+ close(fd);
+
+ munmap(old, sz);
+ close(mfd);
+
+// unlock(name);
+
+ return 0;
+}
+
+int main(int argc, const char *argv[])
+{
+ const char *oldgr, *newgr;
+
+ if (argc != 3) {
+ eputs("Usage: grouprename old-name new-name");
+ return 1;
+ }
+ oldgr = argv[1];
+ newgr = argv[2];
+
+#if 0
+ join(oldgr, newgr, FILE3, FILE3 BACKUP);
+ join(oldgr, newgr, FILE4, FILE4 BACKUP);
+#else
+ join(oldgr, newgr, "test", "test.old");
+#endif
+ return 0;
+}
================================================================
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