diff options
Diffstat (limited to 'shared/systemd/src/basic/fileio.c')
| -rw-r--r-- | shared/systemd/src/basic/fileio.c | 162 |
1 files changed, 138 insertions, 24 deletions
diff --git a/shared/systemd/src/basic/fileio.c b/shared/systemd/src/basic/fileio.c index 3bffa1c5..543dd4eb 100644 --- a/shared/systemd/src/basic/fileio.c +++ b/shared/systemd/src/basic/fileio.c @@ -56,6 +56,44 @@ int fdopen_unlocked(int fd, const char *options, FILE **ret) { return 0; } +int take_fdopen_unlocked(int *fd, const char *options, FILE **ret) { + int r; + + assert(fd); + + r = fdopen_unlocked(*fd, options, ret); + if (r < 0) + return r; + + *fd = -1; + + return 0; +} + +FILE* take_fdopen(int *fd, const char *options) { + assert(fd); + + FILE *f = fdopen(*fd, options); + if (!f) + return NULL; + + *fd = -1; + + return f; +} + +DIR* take_fdopendir(int *dfd) { + assert(dfd); + + DIR *d = fdopendir(*dfd); + if (!d) + return NULL; + + *dfd = -1; + + return d; +} + FILE* open_memstream_unlocked(char **ptr, size_t *sizeloc) { FILE *f = open_memstream(ptr, sizeloc); if (!f) @@ -139,16 +177,21 @@ static int write_string_file_atomic( assert(fn); assert(line); + /* Note that we'd really like to use O_TMPFILE here, but can't really, since we want replacement + * semantics here, and O_TMPFILE can't offer that. i.e. rename() replaces but linkat() doesn't. */ + r = fopen_temporary(fn, &f, &p); if (r < 0) return r; - (void) fchmod_umask(fileno(f), 0644); - r = write_string_stream_ts(f, line, flags, ts); if (r < 0) goto fail; + r = fchmod_umask(fileno(f), FLAGS_SET(flags, WRITE_STRING_FILE_MODE_0600) ? 0600 : 0644); + if (r < 0) + goto fail; + if (rename(p, fn) < 0) { r = -errno; goto fail; @@ -168,7 +211,7 @@ int write_string_file_ts( struct timespec *ts) { _cleanup_fclose_ FILE *f = NULL; - int q, r; + int q, r, fd; assert(fn); assert(line); @@ -193,26 +236,20 @@ int write_string_file_ts( } else assert(!ts); - if (flags & WRITE_STRING_FILE_CREATE) { - r = fopen_unlocked(fn, "we", &f); - if (r < 0) - goto fail; - } else { - int fd; - - /* We manually build our own version of fopen(..., "we") that - * works without O_CREAT */ - fd = open(fn, O_WRONLY|O_CLOEXEC|O_NOCTTY | ((flags & WRITE_STRING_FILE_NOFOLLOW) ? O_NOFOLLOW : 0)); - if (fd < 0) { - r = -errno; - goto fail; - } + /* We manually build our own version of fopen(..., "we") that works without O_CREAT and with O_NOFOLLOW if needed. */ + fd = open(fn, O_WRONLY|O_CLOEXEC|O_NOCTTY | + (FLAGS_SET(flags, WRITE_STRING_FILE_NOFOLLOW) ? O_NOFOLLOW : 0) | + (FLAGS_SET(flags, WRITE_STRING_FILE_CREATE) ? O_CREAT : 0), + (FLAGS_SET(flags, WRITE_STRING_FILE_MODE_0600) ? 0600 : 0666)); + if (fd < 0) { + r = -errno; + goto fail; + } - r = fdopen_unlocked(fd, "w", &f); - if (r < 0) { - safe_close(fd); - goto fail; - } + r = fdopen_unlocked(fd, "w", &f); + if (r < 0) { + safe_close(fd); + goto fail; } if (flags & WRITE_STRING_FILE_DISABLE_BUFFER) @@ -547,17 +584,19 @@ finalize: return r; } -int read_full_file_full(const char *filename, ReadFullFileFlags flags, char **contents, size_t *size) { +int read_full_file_full(int dir_fd, const char *filename, ReadFullFileFlags flags, char **contents, size_t *size) { _cleanup_fclose_ FILE *f = NULL; int r; assert(filename); assert(contents); - r = fopen_unlocked(filename, "re", &f); + r = xfopenat(dir_fd, filename, "re", 0, &f); if (r < 0) return r; + (void) __fsetlocking(f, FSETLOCKING_BYCALLER); + return read_full_stream_full(f, filename, flags, contents, size); } @@ -686,6 +725,81 @@ DIR *xopendirat(int fd, const char *name, int flags) { return d; } +static int mode_to_flags(const char *mode) { + const char *p; + int flags; + + if ((p = startswith(mode, "r+"))) + flags = O_RDWR; + else if ((p = startswith(mode, "r"))) + flags = O_RDONLY; + else if ((p = startswith(mode, "w+"))) + flags = O_RDWR|O_CREAT|O_TRUNC; + else if ((p = startswith(mode, "w"))) + flags = O_WRONLY|O_CREAT|O_TRUNC; + else if ((p = startswith(mode, "a+"))) + flags = O_RDWR|O_CREAT|O_APPEND; + else if ((p = startswith(mode, "a"))) + flags = O_WRONLY|O_CREAT|O_APPEND; + else + return -EINVAL; + + for (; *p != 0; p++) { + + switch (*p) { + + case 'e': + flags |= O_CLOEXEC; + break; + + case 'x': + flags |= O_EXCL; + break; + + case 'm': + /* ignore this here, fdopen() might care later though */ + break; + + case 'c': /* not sure what to do about this one */ + default: + return -EINVAL; + } + } + + return flags; +} + +int xfopenat(int dir_fd, const char *path, const char *mode, int flags, FILE **ret) { + FILE *f; + + /* A combination of fopen() with openat() */ + + if (dir_fd == AT_FDCWD && flags == 0) { + f = fopen(path, mode); + if (!f) + return -errno; + } else { + int fd, mode_flags; + + mode_flags = mode_to_flags(mode); + if (mode_flags < 0) + return mode_flags; + + fd = openat(dir_fd, path, mode_flags | flags); + if (fd < 0) + return -errno; + + f = fdopen(fd, mode); + if (!f) { + safe_close(fd); + return -errno; + } + } + + *ret = f; + return 0; +} + #if 0 /* NM_IGNORED */ static int search_and_fopen_internal(const char *path, const char *mode, const char *root, char **search, FILE **_f) { char **i; |