summaryrefslogtreecommitdiffstats
path: root/lib/iolog/iolog_open.c
diff options
context:
space:
mode:
Diffstat (limited to 'lib/iolog/iolog_open.c')
-rw-r--r--lib/iolog/iolog_open.c127
1 files changed, 127 insertions, 0 deletions
diff --git a/lib/iolog/iolog_open.c b/lib/iolog/iolog_open.c
new file mode 100644
index 0000000..c2556a7
--- /dev/null
+++ b/lib/iolog/iolog_open.c
@@ -0,0 +1,127 @@
+/*
+ * SPDX-License-Identifier: ISC
+ *
+ * Copyright (c) 2009-2021 Todd C. Miller <Todd.Miller@sudo.ws>
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+/*
+ * This is an open source non-commercial project. Dear PVS-Studio, please check it.
+ * PVS-Studio Static Code Analyzer for C, C++ and C#: http://www.viva64.com
+ */
+
+#include <config.h>
+
+#include <stdio.h>
+#include <stdlib.h>
+#ifdef HAVE_STDBOOL_H
+# include <stdbool.h>
+#else
+# include "compat/stdbool.h"
+#endif
+#include <errno.h>
+#include <fcntl.h>
+#include <time.h>
+#include <unistd.h>
+
+#include "sudo_compat.h"
+#include "sudo_debug.h"
+#include "sudo_iolog.h"
+#include "sudo_util.h"
+
+static unsigned char const gzip_magic[2] = {0x1f, 0x8b};
+
+/*
+ * Open the specified I/O log file and store in iol.
+ * Stores the open file handle which has the close-on-exec flag set.
+ */
+bool
+iolog_open(struct iolog_file *iol, int dfd, int iofd, const char *mode)
+{
+ int flags;
+ const char *file;
+ unsigned char magic[2];
+ const uid_t iolog_uid = iolog_get_uid();
+ const gid_t iolog_gid = iolog_get_gid();
+ debug_decl(iolog_open, SUDO_DEBUG_UTIL);
+
+ if (mode[0] == 'r') {
+ flags = mode[1] == '+' ? O_RDWR : O_RDONLY;
+ } else if (mode[0] == 'w') {
+ flags = O_CREAT|O_TRUNC;
+ flags |= mode[1] == '+' ? O_RDWR : O_WRONLY;
+ } else {
+ sudo_debug_printf(SUDO_DEBUG_ERROR,
+ "%s: invalid I/O mode %s", __func__, mode);
+ debug_return_bool(false);
+ }
+ if ((file = iolog_fd_to_name(iofd)) == NULL) {
+ sudo_debug_printf(SUDO_DEBUG_ERROR,
+ "%s: invalid iofd %d", __func__, iofd);
+ debug_return_bool(false);
+ }
+
+ iol->writable = false;
+ iol->compressed = false;
+ if (iol->enabled) {
+ int fd = iolog_openat(dfd, file, flags);
+ if (fd != -1) {
+ if (*mode == 'w') {
+ if (fchown(fd, iolog_uid, iolog_gid) != 0) {
+ sudo_debug_printf(SUDO_DEBUG_ERROR|SUDO_DEBUG_ERRNO,
+ "%s: unable to fchown %d:%d %s", __func__,
+ (int)iolog_uid, (int)iolog_gid, file);
+ }
+ iol->compressed = iolog_get_compress();
+ } else {
+ /* check for gzip magic number */
+ if (pread(fd, magic, sizeof(magic), 0) == ssizeof(magic)) {
+ if (magic[0] == gzip_magic[0] && magic[1] == gzip_magic[1])
+ iol->compressed = true;
+ }
+ }
+ if (fcntl(fd, F_SETFD, FD_CLOEXEC) != -1) {
+#ifdef HAVE_ZLIB_H
+ if (iol->compressed)
+ iol->fd.g = gzdopen(fd, mode);
+ else
+#endif
+ iol->fd.f = fdopen(fd, mode);
+ }
+ if (iol->fd.v != NULL) {
+ switch ((flags & O_ACCMODE)) {
+ case O_WRONLY:
+ case O_RDWR:
+ iol->writable = true;
+ break;
+ }
+ } else {
+ int save_errno = errno;
+ close(fd);
+ errno = save_errno;
+ fd = -1;
+ }
+ }
+ if (fd == -1) {
+ iol->enabled = false;
+ debug_return_bool(false);
+ }
+ } else {
+ if (*mode == 'w') {
+ /* Remove old log file in case we recycled sequence numbers. */
+ (void)unlinkat(dfd, file, 0);
+ }
+ }
+ debug_return_bool(true);
+}