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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-28 09:51:24 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-28 09:51:24 +0000 |
commit | f7548d6d28c313cf80e6f3ef89aed16a19815df1 (patch) | |
tree | a3f6f2a3f247293bee59ecd28e8cd8ceb6ca064a /src/lib/safe-mkstemp.c | |
parent | Initial commit. (diff) | |
download | dovecot-upstream.tar.xz dovecot-upstream.zip |
Adding upstream version 1:2.3.19.1+dfsg1.upstream/1%2.3.19.1+dfsg1upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'src/lib/safe-mkstemp.c')
-rw-r--r-- | src/lib/safe-mkstemp.c | 106 |
1 files changed, 106 insertions, 0 deletions
diff --git a/src/lib/safe-mkstemp.c b/src/lib/safe-mkstemp.c new file mode 100644 index 0000000..27b401e --- /dev/null +++ b/src/lib/safe-mkstemp.c @@ -0,0 +1,106 @@ +/* Copyright (c) 2007-2018 Dovecot authors, see the included COPYING file */ + +#include "lib.h" +#include "str.h" +#include "hex-binary.h" +#include "randgen.h" +#include "hostpid.h" +#include "eacces-error.h" +#include "safe-mkstemp.h" + +#include <unistd.h> +#include <fcntl.h> +#include <sys/stat.h> + +static int ATTR_NULL(5) +safe_mkstemp_full(string_t *prefix, mode_t mode, uid_t uid, gid_t gid, + const char *gid_origin) +{ + size_t prefix_len; + struct stat st; + unsigned char randbuf[8]; + mode_t old_umask; + int fd; + + prefix_len = str_len(prefix); + for (;;) { + do { + random_fill(randbuf, sizeof(randbuf)); + str_truncate(prefix, prefix_len); + str_append(prefix, + binary_to_hex(randbuf, sizeof(randbuf))); + } while (lstat(str_c(prefix), &st) == 0); + + if (errno != ENOENT) { + i_error("stat(%s) failed: %m", str_c(prefix)); + str_truncate(prefix, prefix_len); + return -1; + } + + old_umask = umask(0666 ^ mode); + fd = open(str_c(prefix), O_RDWR | O_EXCL | O_CREAT, 0666); + umask(old_umask); + if (fd != -1) + break; + + if (errno != EEXIST) { + if (errno != ENOENT && errno != EACCES) + i_error("open(%s) failed: %m", str_c(prefix)); + str_truncate(prefix, prefix_len); + return -1; + } + } + if (uid == (uid_t)-1 && gid == (gid_t)-1) + return fd; + + if (fchown(fd, uid, gid) < 0) { + if (errno == EPERM) { + i_error("%s", eperm_error_get_chgrp("fchown", + str_c(prefix), gid, gid_origin)); + } else { + i_error("fchown(%s, %ld, %ld) failed: %m", + str_c(prefix), + uid == (uid_t)-1 ? -1L : (long)uid, + gid == (gid_t)-1 ? -1L : (long)gid); + } + i_close_fd(&fd); + i_unlink(str_c(prefix)); + str_truncate(prefix, prefix_len); + return -1; + } + return fd; +} + +int safe_mkstemp(string_t *prefix, mode_t mode, uid_t uid, gid_t gid) +{ + return safe_mkstemp_full(prefix, mode, uid, gid, NULL); +} + +int safe_mkstemp_group(string_t *prefix, mode_t mode, + gid_t gid, const char *gid_origin) +{ + return safe_mkstemp_full(prefix, mode, (uid_t)-1, gid, gid_origin); +} + +int safe_mkstemp_hostpid(string_t *prefix, mode_t mode, uid_t uid, gid_t gid) +{ + size_t orig_prefix_len = str_len(prefix); + int fd; + + str_printfa(prefix, "%s.%s.", my_hostname, my_pid); + if ((fd = safe_mkstemp(prefix, mode, uid, gid)) == -1) + str_truncate(prefix, orig_prefix_len); + return fd; +} + +int safe_mkstemp_hostpid_group(string_t *prefix, mode_t mode, + gid_t gid, const char *gid_origin) +{ + size_t orig_prefix_len = str_len(prefix); + int fd; + + str_printfa(prefix, "%s.%s.", my_hostname, my_pid); + if ((fd = safe_mkstemp_group(prefix, mode, gid, gid_origin)) == -1) + str_truncate(prefix, orig_prefix_len); + return fd; +} |