910 lines
25 KiB
C
910 lines
25 KiB
C
/* SPDX-License-Identifier: LGPL-2.1+ */
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#include <ctype.h>
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#include <errno.h>
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#include <fcntl.h>
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#include <limits.h>
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#include <stdarg.h>
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#include <stdint.h>
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#include <stdio_ext.h>
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#include <stdlib.h>
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#include <string.h>
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#include <sys/stat.h>
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#include <sys/types.h>
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#include <unistd.h>
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#include "alloc-util.h"
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#include "fd-util.h"
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#include "fileio.h"
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#include "fs-util.h"
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#include "hexdecoct.h"
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#include "log.h"
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#include "macro.h"
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#include "missing.h"
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#include "parse-util.h"
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#include "path-util.h"
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#include "stdio-util.h"
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#include "string-util.h"
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#include "tmpfile-util.h"
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#define READ_FULL_BYTES_MAX (4U*1024U*1024U)
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int fopen_unlocked(const char *path, const char *options, FILE **ret) {
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assert(ret);
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FILE *f = fopen(path, options);
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if (!f)
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return -errno;
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(void) __fsetlocking(f, FSETLOCKING_BYCALLER);
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*ret = f;
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return 0;
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}
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int fdopen_unlocked(int fd, const char *options, FILE **ret) {
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assert(ret);
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FILE *f = fdopen(fd, options);
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if (!f)
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return -errno;
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(void) __fsetlocking(f, FSETLOCKING_BYCALLER);
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*ret = f;
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return 0;
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}
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FILE* open_memstream_unlocked(char **ptr, size_t *sizeloc) {
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FILE *f = open_memstream(ptr, sizeloc);
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if (!f)
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return NULL;
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(void) __fsetlocking(f, FSETLOCKING_BYCALLER);
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return f;
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}
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int write_string_stream_ts(
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FILE *f,
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const char *line,
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WriteStringFileFlags flags,
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struct timespec *ts) {
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bool needs_nl;
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int r;
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assert(f);
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assert(line);
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if (ferror(f))
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return -EIO;
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needs_nl = !(flags & WRITE_STRING_FILE_AVOID_NEWLINE) && !endswith(line, "\n");
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if (needs_nl && (flags & WRITE_STRING_FILE_DISABLE_BUFFER)) {
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/* If STDIO buffering was disabled, then let's append the newline character to the string itself, so
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* that the write goes out in one go, instead of two */
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line = strjoina(line, "\n");
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needs_nl = false;
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}
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if (fputs(line, f) == EOF)
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return -errno;
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if (needs_nl)
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if (fputc('\n', f) == EOF)
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return -errno;
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if (flags & WRITE_STRING_FILE_SYNC)
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r = fflush_sync_and_check(f);
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else
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r = fflush_and_check(f);
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if (r < 0)
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return r;
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if (ts) {
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struct timespec twice[2] = {*ts, *ts};
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if (futimens(fileno(f), twice) < 0)
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return -errno;
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}
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return 0;
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}
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static int write_string_file_atomic(
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const char *fn,
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const char *line,
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WriteStringFileFlags flags,
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struct timespec *ts) {
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_cleanup_fclose_ FILE *f = NULL;
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_cleanup_free_ char *p = NULL;
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int r;
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assert(fn);
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assert(line);
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r = fopen_temporary(fn, &f, &p);
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if (r < 0)
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return r;
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(void) fchmod_umask(fileno(f), 0644);
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r = write_string_stream_ts(f, line, flags, ts);
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if (r < 0)
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goto fail;
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if (rename(p, fn) < 0) {
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r = -errno;
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goto fail;
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}
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return 0;
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fail:
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(void) unlink(p);
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return r;
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}
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int write_string_file_ts(
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const char *fn,
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const char *line,
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WriteStringFileFlags flags,
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struct timespec *ts) {
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_cleanup_fclose_ FILE *f = NULL;
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int q, r;
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assert(fn);
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assert(line);
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/* We don't know how to verify whether the file contents was already on-disk. */
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assert(!((flags & WRITE_STRING_FILE_VERIFY_ON_FAILURE) && (flags & WRITE_STRING_FILE_SYNC)));
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if (flags & WRITE_STRING_FILE_ATOMIC) {
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assert(flags & WRITE_STRING_FILE_CREATE);
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r = write_string_file_atomic(fn, line, flags, ts);
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if (r < 0)
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goto fail;
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return r;
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} else
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assert(!ts);
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if (flags & WRITE_STRING_FILE_CREATE) {
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r = fopen_unlocked(fn, "we", &f);
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if (r < 0)
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goto fail;
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} else {
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int fd;
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/* We manually build our own version of fopen(..., "we") that
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* works without O_CREAT */
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fd = open(fn, O_WRONLY|O_CLOEXEC|O_NOCTTY | ((flags & WRITE_STRING_FILE_NOFOLLOW) ? O_NOFOLLOW : 0));
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if (fd < 0) {
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r = -errno;
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goto fail;
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}
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r = fdopen_unlocked(fd, "w", &f);
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if (r < 0) {
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safe_close(fd);
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goto fail;
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}
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}
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if (flags & WRITE_STRING_FILE_DISABLE_BUFFER)
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setvbuf(f, NULL, _IONBF, 0);
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r = write_string_stream_ts(f, line, flags, ts);
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if (r < 0)
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goto fail;
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return 0;
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fail:
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if (!(flags & WRITE_STRING_FILE_VERIFY_ON_FAILURE))
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return r;
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f = safe_fclose(f);
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/* OK, the operation failed, but let's see if the right
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* contents in place already. If so, eat up the error. */
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q = verify_file(fn, line, !(flags & WRITE_STRING_FILE_AVOID_NEWLINE));
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if (q <= 0)
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return r;
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return 0;
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}
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int write_string_filef(
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const char *fn,
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WriteStringFileFlags flags,
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const char *format, ...) {
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_cleanup_free_ char *p = NULL;
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va_list ap;
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int r;
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va_start(ap, format);
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r = vasprintf(&p, format, ap);
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va_end(ap);
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if (r < 0)
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return -ENOMEM;
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return write_string_file(fn, p, flags);
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}
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int read_one_line_file(const char *fn, char **line) {
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_cleanup_fclose_ FILE *f = NULL;
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int r;
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assert(fn);
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assert(line);
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r = fopen_unlocked(fn, "re", &f);
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if (r < 0)
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return r;
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return read_line(f, LONG_LINE_MAX, line);
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}
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int verify_file(const char *fn, const char *blob, bool accept_extra_nl) {
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_cleanup_fclose_ FILE *f = NULL;
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_cleanup_free_ char *buf = NULL;
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size_t l, k;
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int r;
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assert(fn);
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assert(blob);
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l = strlen(blob);
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if (accept_extra_nl && endswith(blob, "\n"))
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accept_extra_nl = false;
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buf = malloc(l + accept_extra_nl + 1);
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if (!buf)
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return -ENOMEM;
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r = fopen_unlocked(fn, "re", &f);
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if (r < 0)
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return r;
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/* We try to read one byte more than we need, so that we know whether we hit eof */
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errno = 0;
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k = fread(buf, 1, l + accept_extra_nl + 1, f);
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if (ferror(f))
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return errno > 0 ? -errno : -EIO;
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if (k != l && k != l + accept_extra_nl)
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return 0;
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if (memcmp(buf, blob, l) != 0)
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return 0;
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if (k > l && buf[l] != '\n')
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return 0;
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return 1;
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}
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int read_full_stream_full(
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FILE *f,
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const char *filename,
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ReadFullFileFlags flags,
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char **ret_contents,
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size_t *ret_size) {
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_cleanup_free_ char *buf = NULL;
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struct stat st;
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size_t n, n_next, l;
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int fd, r;
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assert(f);
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assert(ret_contents);
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assert(!(flags & READ_FULL_FILE_UNBASE64) || ret_size);
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n_next = LINE_MAX; /* Start size */
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fd = fileno(f);
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if (fd >= 0) { /* If the FILE* object is backed by an fd (as opposed to memory or such, see fmemopen(), let's
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* optimize our buffering) */
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if (fstat(fd, &st) < 0)
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return -errno;
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if (S_ISREG(st.st_mode)) {
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/* Safety check */
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if (st.st_size > READ_FULL_BYTES_MAX)
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return -E2BIG;
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/* Start with the right file size, but be prepared for files from /proc which generally report a file
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* size of 0. Note that we increase the size to read here by one, so that the first read attempt
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* already makes us notice the EOF. */
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if (st.st_size > 0)
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n_next = st.st_size + 1;
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if (flags & READ_FULL_FILE_SECURE)
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(void) warn_file_is_world_accessible(filename, &st, NULL, 0);
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}
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}
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n = l = 0;
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for (;;) {
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char *t;
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size_t k;
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if (flags & READ_FULL_FILE_SECURE) {
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t = malloc(n_next + 1);
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if (!t) {
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r = -ENOMEM;
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goto finalize;
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}
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memcpy_safe(t, buf, n);
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explicit_bzero_safe(buf, n);
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} else {
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t = realloc(buf, n_next + 1);
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if (!t)
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return -ENOMEM;
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}
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buf = t;
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n = n_next;
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errno = 0;
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k = fread(buf + l, 1, n - l, f);
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if (k > 0)
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l += k;
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if (ferror(f)) {
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r = errno > 0 ? -errno : -EIO;
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goto finalize;
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}
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if (feof(f))
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break;
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/* We aren't expecting fread() to return a short read outside
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* of (error && eof), assert buffer is full and enlarge buffer.
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*/
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assert(l == n);
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/* Safety check */
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if (n >= READ_FULL_BYTES_MAX) {
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r = -E2BIG;
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goto finalize;
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}
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n_next = MIN(n * 2, READ_FULL_BYTES_MAX);
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}
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if (flags & READ_FULL_FILE_UNBASE64) {
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buf[l++] = 0;
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r = unbase64mem_full(buf, l, flags & READ_FULL_FILE_SECURE, (void **) ret_contents, ret_size);
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goto finalize;
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}
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if (!ret_size) {
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/* Safety check: if the caller doesn't want to know the size of what we just read it will rely on the
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* trailing NUL byte. But if there's an embedded NUL byte, then we should refuse operation as otherwise
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* there'd be ambiguity about what we just read. */
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if (memchr(buf, 0, l)) {
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r = -EBADMSG;
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goto finalize;
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}
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}
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buf[l] = 0;
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*ret_contents = TAKE_PTR(buf);
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if (ret_size)
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*ret_size = l;
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return 0;
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finalize:
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if (flags & READ_FULL_FILE_SECURE)
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explicit_bzero_safe(buf, n);
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return r;
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}
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int read_full_file_full(const char *filename, ReadFullFileFlags flags, char **contents, size_t *size) {
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_cleanup_fclose_ FILE *f = NULL;
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int r;
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assert(filename);
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assert(contents);
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r = fopen_unlocked(filename, "re", &f);
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if (r < 0)
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return r;
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return read_full_stream_full(f, filename, flags, contents, size);
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}
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int executable_is_script(const char *path, char **interpreter) {
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_cleanup_free_ char *line = NULL;
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size_t len;
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char *ans;
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int r;
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assert(path);
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r = read_one_line_file(path, &line);
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if (r == -ENOBUFS) /* First line overly long? if so, then it's not a script */
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return 0;
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if (r < 0)
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return r;
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if (!startswith(line, "#!"))
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return 0;
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ans = strstrip(line + 2);
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len = strcspn(ans, " \t");
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if (len == 0)
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return 0;
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ans = strndup(ans, len);
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if (!ans)
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return -ENOMEM;
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*interpreter = ans;
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return 1;
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}
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/**
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* Retrieve one field from a file like /proc/self/status. pattern
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* should not include whitespace or the delimiter (':'). pattern matches only
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* the beginning of a line. Whitespace before ':' is skipped. Whitespace and
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* zeros after the ':' will be skipped. field must be freed afterwards.
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* terminator specifies the terminating characters of the field value (not
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* included in the value).
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*/
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int get_proc_field(const char *filename, const char *pattern, const char *terminator, char **field) {
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_cleanup_free_ char *status = NULL;
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char *t, *f;
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size_t len;
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int r;
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assert(terminator);
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assert(filename);
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assert(pattern);
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assert(field);
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r = read_full_file(filename, &status, NULL);
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if (r < 0)
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return r;
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t = status;
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do {
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bool pattern_ok;
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do {
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t = strstr(t, pattern);
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if (!t)
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return -ENOENT;
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/* Check that pattern occurs in beginning of line. */
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pattern_ok = (t == status || t[-1] == '\n');
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t += strlen(pattern);
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} while (!pattern_ok);
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t += strspn(t, " \t");
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if (!*t)
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return -ENOENT;
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} while (*t != ':');
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t++;
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if (*t) {
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t += strspn(t, " \t");
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/* Also skip zeros, because when this is used for
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* capabilities, we don't want the zeros. This way the
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* same capability set always maps to the same string,
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* irrespective of the total capability set size. For
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* other numbers it shouldn't matter. */
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t += strspn(t, "0");
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/* Back off one char if there's nothing but whitespace
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and zeros */
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if (!*t || isspace(*t))
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t--;
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}
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len = strcspn(t, terminator);
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f = strndup(t, len);
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if (!f)
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return -ENOMEM;
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*field = f;
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return 0;
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}
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DIR *xopendirat(int fd, const char *name, int flags) {
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int nfd;
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DIR *d;
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assert(!(flags & O_CREAT));
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nfd = openat(fd, name, O_RDONLY|O_NONBLOCK|O_DIRECTORY|O_CLOEXEC|flags, 0);
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if (nfd < 0)
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return NULL;
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d = fdopendir(nfd);
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if (!d) {
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safe_close(nfd);
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return NULL;
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}
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return d;
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}
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static int search_and_fopen_internal(const char *path, const char *mode, const char *root, char **search, FILE **_f) {
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char **i;
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assert(path);
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assert(mode);
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assert(_f);
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if (!path_strv_resolve_uniq(search, root))
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return -ENOMEM;
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STRV_FOREACH(i, search) {
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_cleanup_free_ char *p = NULL;
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FILE *f;
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if (root)
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p = strjoin(root, *i, "/", path);
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else
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p = strjoin(*i, "/", path);
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if (!p)
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return -ENOMEM;
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f = fopen(p, mode);
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if (f) {
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*_f = f;
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return 0;
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}
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if (errno != ENOENT)
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return -errno;
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}
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return -ENOENT;
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}
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|
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int search_and_fopen(const char *path, const char *mode, const char *root, const char **search, FILE **_f) {
|
|
_cleanup_strv_free_ char **copy = NULL;
|
|
|
|
assert(path);
|
|
assert(mode);
|
|
assert(_f);
|
|
|
|
if (path_is_absolute(path)) {
|
|
FILE *f;
|
|
|
|
f = fopen(path, mode);
|
|
if (f) {
|
|
*_f = f;
|
|
return 0;
|
|
}
|
|
|
|
return -errno;
|
|
}
|
|
|
|
copy = strv_copy((char**) search);
|
|
if (!copy)
|
|
return -ENOMEM;
|
|
|
|
return search_and_fopen_internal(path, mode, root, copy, _f);
|
|
}
|
|
|
|
int search_and_fopen_nulstr(const char *path, const char *mode, const char *root, const char *search, FILE **_f) {
|
|
_cleanup_strv_free_ char **s = NULL;
|
|
|
|
if (path_is_absolute(path)) {
|
|
FILE *f;
|
|
|
|
f = fopen(path, mode);
|
|
if (f) {
|
|
*_f = f;
|
|
return 0;
|
|
}
|
|
|
|
return -errno;
|
|
}
|
|
|
|
s = strv_split_nulstr(search);
|
|
if (!s)
|
|
return -ENOMEM;
|
|
|
|
return search_and_fopen_internal(path, mode, root, s, _f);
|
|
}
|
|
|
|
int fflush_and_check(FILE *f) {
|
|
assert(f);
|
|
|
|
errno = 0;
|
|
fflush(f);
|
|
|
|
if (ferror(f))
|
|
return errno > 0 ? -errno : -EIO;
|
|
|
|
return 0;
|
|
}
|
|
|
|
int fflush_sync_and_check(FILE *f) {
|
|
int r;
|
|
|
|
assert(f);
|
|
|
|
r = fflush_and_check(f);
|
|
if (r < 0)
|
|
return r;
|
|
|
|
if (fsync(fileno(f)) < 0)
|
|
return -errno;
|
|
|
|
r = fsync_directory_of_file(fileno(f));
|
|
if (r < 0)
|
|
return r;
|
|
|
|
return 0;
|
|
}
|
|
|
|
int write_timestamp_file_atomic(const char *fn, usec_t n) {
|
|
char ln[DECIMAL_STR_MAX(n)+2];
|
|
|
|
/* Creates a "timestamp" file, that contains nothing but a
|
|
* usec_t timestamp, formatted in ASCII. */
|
|
|
|
if (n <= 0 || n >= USEC_INFINITY)
|
|
return -ERANGE;
|
|
|
|
xsprintf(ln, USEC_FMT "\n", n);
|
|
|
|
return write_string_file(fn, ln, WRITE_STRING_FILE_CREATE|WRITE_STRING_FILE_ATOMIC);
|
|
}
|
|
|
|
int read_timestamp_file(const char *fn, usec_t *ret) {
|
|
_cleanup_free_ char *ln = NULL;
|
|
uint64_t t;
|
|
int r;
|
|
|
|
r = read_one_line_file(fn, &ln);
|
|
if (r < 0)
|
|
return r;
|
|
|
|
r = safe_atou64(ln, &t);
|
|
if (r < 0)
|
|
return r;
|
|
|
|
if (t <= 0 || t >= (uint64_t) USEC_INFINITY)
|
|
return -ERANGE;
|
|
|
|
*ret = (usec_t) t;
|
|
return 0;
|
|
}
|
|
|
|
int fputs_with_space(FILE *f, const char *s, const char *separator, bool *space) {
|
|
int r;
|
|
|
|
assert(s);
|
|
|
|
/* Outputs the specified string with fputs(), but optionally prefixes it with a separator. The *space parameter
|
|
* when specified shall initially point to a boolean variable initialized to false. It is set to true after the
|
|
* first invocation. This call is supposed to be use in loops, where a separator shall be inserted between each
|
|
* element, but not before the first one. */
|
|
|
|
if (!f)
|
|
f = stdout;
|
|
|
|
if (space) {
|
|
if (!separator)
|
|
separator = " ";
|
|
|
|
if (*space) {
|
|
r = fputs(separator, f);
|
|
if (r < 0)
|
|
return r;
|
|
}
|
|
|
|
*space = true;
|
|
}
|
|
|
|
return fputs(s, f);
|
|
}
|
|
|
|
/* A bitmask of the EOL markers we know */
|
|
typedef enum EndOfLineMarker {
|
|
EOL_NONE = 0,
|
|
EOL_ZERO = 1 << 0, /* \0 (aka NUL) */
|
|
EOL_TEN = 1 << 1, /* \n (aka NL, aka LF) */
|
|
EOL_THIRTEEN = 1 << 2, /* \r (aka CR) */
|
|
} EndOfLineMarker;
|
|
|
|
static EndOfLineMarker categorize_eol(char c, ReadLineFlags flags) {
|
|
|
|
if (!IN_SET(flags, READ_LINE_ONLY_NUL)) {
|
|
if (c == '\n')
|
|
return EOL_TEN;
|
|
if (c == '\r')
|
|
return EOL_THIRTEEN;
|
|
}
|
|
|
|
if (c == '\0')
|
|
return EOL_ZERO;
|
|
|
|
return EOL_NONE;
|
|
}
|
|
|
|
DEFINE_TRIVIAL_CLEANUP_FUNC(FILE*, funlockfile);
|
|
|
|
int read_line_full(FILE *f, size_t limit, ReadLineFlags flags, char **ret) {
|
|
size_t n = 0, allocated = 0, count = 0;
|
|
_cleanup_free_ char *buffer = NULL;
|
|
int r;
|
|
|
|
assert(f);
|
|
|
|
/* Something like a bounded version of getline().
|
|
*
|
|
* Considers EOF, \n, \r and \0 end of line delimiters (or combinations of these), and does not include these
|
|
* delimiters in the string returned. Specifically, recognizes the following combinations of markers as line
|
|
* endings:
|
|
*
|
|
* • \n (UNIX)
|
|
* • \r (old MacOS)
|
|
* • \0 (C strings)
|
|
* • \n\0
|
|
* • \r\0
|
|
* • \r\n (Windows)
|
|
* • \n\r
|
|
* • \r\n\0
|
|
* • \n\r\0
|
|
*
|
|
* Returns the number of bytes read from the files (i.e. including delimiters — this hence usually differs from
|
|
* the number of characters in the returned string). When EOF is hit, 0 is returned.
|
|
*
|
|
* The input parameter limit is the maximum numbers of characters in the returned string, i.e. excluding
|
|
* delimiters. If the limit is hit we fail and return -ENOBUFS.
|
|
*
|
|
* If a line shall be skipped ret may be initialized as NULL. */
|
|
|
|
if (ret) {
|
|
if (!GREEDY_REALLOC(buffer, allocated, 1))
|
|
return -ENOMEM;
|
|
}
|
|
|
|
{
|
|
_unused_ _cleanup_(funlockfilep) FILE *flocked = f;
|
|
EndOfLineMarker previous_eol = EOL_NONE;
|
|
flockfile(f);
|
|
|
|
for (;;) {
|
|
EndOfLineMarker eol;
|
|
char c;
|
|
|
|
if (n >= limit)
|
|
return -ENOBUFS;
|
|
|
|
if (count >= INT_MAX) /* We couldn't return the counter anymore as "int", hence refuse this */
|
|
return -ENOBUFS;
|
|
|
|
r = safe_fgetc(f, &c);
|
|
if (r < 0)
|
|
return r;
|
|
if (r == 0) /* EOF is definitely EOL */
|
|
break;
|
|
|
|
eol = categorize_eol(c, flags);
|
|
|
|
if (FLAGS_SET(previous_eol, EOL_ZERO) ||
|
|
(eol == EOL_NONE && previous_eol != EOL_NONE) ||
|
|
(eol != EOL_NONE && (previous_eol & eol) != 0)) {
|
|
/* Previous char was a NUL? This is not an EOL, but the previous char was? This type of
|
|
* EOL marker has been seen right before? In either of these three cases we are
|
|
* done. But first, let's put this character back in the queue. (Note that we have to
|
|
* cast this to (unsigned char) here as ungetc() expects a positive 'int', and if we
|
|
* are on an architecture where 'char' equals 'signed char' we need to ensure we don't
|
|
* pass a negative value here. That said, to complicate things further ungetc() is
|
|
* actually happy with most negative characters and implicitly casts them back to
|
|
* positive ones as needed, except for \xff (aka -1, aka EOF), which it refuses. What a
|
|
* godawful API!) */
|
|
assert_se(ungetc((unsigned char) c, f) != EOF);
|
|
break;
|
|
}
|
|
|
|
count++;
|
|
|
|
if (eol != EOL_NONE) {
|
|
previous_eol |= eol;
|
|
continue;
|
|
}
|
|
|
|
if (ret) {
|
|
if (!GREEDY_REALLOC(buffer, allocated, n + 2))
|
|
return -ENOMEM;
|
|
|
|
buffer[n] = c;
|
|
}
|
|
|
|
n++;
|
|
}
|
|
}
|
|
|
|
if (ret) {
|
|
buffer[n] = 0;
|
|
|
|
*ret = TAKE_PTR(buffer);
|
|
}
|
|
|
|
return (int) count;
|
|
}
|
|
|
|
int safe_fgetc(FILE *f, char *ret) {
|
|
int k;
|
|
|
|
assert(f);
|
|
|
|
/* A safer version of plain fgetc(): let's propagate the error that happened while reading as such, and
|
|
* separate the EOF condition from the byte read, to avoid those confusion signed/unsigned issues fgetc()
|
|
* has. */
|
|
|
|
errno = 0;
|
|
k = fgetc(f);
|
|
if (k == EOF) {
|
|
if (ferror(f))
|
|
return errno > 0 ? -errno : -EIO;
|
|
|
|
if (ret)
|
|
*ret = 0;
|
|
|
|
return 0;
|
|
}
|
|
|
|
if (ret)
|
|
*ret = k;
|
|
|
|
return 1;
|
|
}
|
|
|
|
int warn_file_is_world_accessible(const char *filename, struct stat *st, const char *unit, unsigned line) {
|
|
struct stat _st;
|
|
|
|
if (!filename)
|
|
return 0;
|
|
|
|
if (!st) {
|
|
if (stat(filename, &_st) < 0)
|
|
return -errno;
|
|
st = &_st;
|
|
}
|
|
|
|
if ((st->st_mode & S_IRWXO) == 0)
|
|
return 0;
|
|
|
|
if (unit)
|
|
log_syntax(unit, LOG_WARNING, filename, line, 0,
|
|
"%s has %04o mode that is too permissive, please adjust the access mode.",
|
|
filename, st->st_mode & 07777);
|
|
else
|
|
log_warning("%s has %04o mode that is too permissive, please adjust the access mode.",
|
|
filename, st->st_mode & 07777);
|
|
return 0;
|
|
}
|