| /* SPDX-License-Identifier: LGPL-2.1-or-later */ |
| |
| #include <ctype.h> |
| #include <errno.h> |
| #include <fcntl.h> |
| #include <limits.h> |
| #include <stdarg.h> |
| #include <stdint.h> |
| #include <stdio_ext.h> |
| #include <stdlib.h> |
| #include <sys/stat.h> |
| #include <sys/types.h> |
| #include <unistd.h> |
| |
| #include "alloc-util.h" |
| #include "chase-symlinks.h" |
| #include "fd-util.h" |
| #include "fileio.h" |
| #include "fs-util.h" |
| #include "hexdecoct.h" |
| #include "log.h" |
| #include "macro.h" |
| #include "mkdir.h" |
| #include "nulstr-util.h" |
| #include "parse-util.h" |
| #include "path-util.h" |
| #include "socket-util.h" |
| #include "stdio-util.h" |
| #include "string-util.h" |
| #include "sync-util.h" |
| #include "tmpfile-util.h" |
| |
| /* The maximum size of the file we'll read in one go in read_full_file() (64M). */ |
| #define READ_FULL_BYTES_MAX (64U*1024U*1024U - 1U) |
| |
| /* The maximum size of virtual files (i.e. procfs, sysfs, and other virtual "API" files) we'll read in one go |
| * in read_virtual_file(). Note that this limit is different (and much lower) than the READ_FULL_BYTES_MAX |
| * limit. This reflects the fact that we use different strategies for reading virtual and regular files: |
| * virtual files we generally have to read in a single read() syscall since the kernel doesn't support |
| * continuation read()s for them. Thankfully they are somewhat size constrained. Thus we can allocate the |
| * full potential buffer in advance. Regular files OTOH can be much larger, and there we grow the allocations |
| * exponentially in a loop. We use a size limit of 4M-2 because 4M-1 is the maximum buffer that /proc/sys/ |
| * allows us to read() (larger reads will fail with ENOMEM), and we want to read one extra byte so that we |
| * can detect EOFs. */ |
| #define READ_VIRTUAL_BYTES_MAX (4U*1024U*1024U - 2U) |
| |
| int fopen_unlocked_at(int dir_fd, const char *path, const char *options, int flags, FILE **ret) { |
| int r; |
| |
| assert(ret); |
| |
| r = xfopenat(dir_fd, path, options, flags, ret); |
| if (r < 0) |
| return r; |
| |
| (void) __fsetlocking(*ret, FSETLOCKING_BYCALLER); |
| |
| return 0; |
| } |
| |
| int fdopen_unlocked(int fd, const char *options, FILE **ret) { |
| assert(ret); |
| |
| FILE *f = fdopen(fd, options); |
| if (!f) |
| return -errno; |
| |
| (void) __fsetlocking(f, FSETLOCKING_BYCALLER); |
| |
| *ret = f; |
| 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 = -EBADF; |
| |
| return 0; |
| } |
| |
| FILE* take_fdopen(int *fd, const char *options) { |
| assert(fd); |
| |
| FILE *f = fdopen(*fd, options); |
| if (!f) |
| return NULL; |
| |
| *fd = -EBADF; |
| |
| return f; |
| } |
| |
| DIR* take_fdopendir(int *dfd) { |
| assert(dfd); |
| |
| DIR *d = fdopendir(*dfd); |
| if (!d) |
| return NULL; |
| |
| *dfd = -EBADF; |
| |
| return d; |
| } |
| |
| FILE* open_memstream_unlocked(char **ptr, size_t *sizeloc) { |
| FILE *f = open_memstream(ptr, sizeloc); |
| if (!f) |
| return NULL; |
| |
| (void) __fsetlocking(f, FSETLOCKING_BYCALLER); |
| |
| return f; |
| } |
| |
| FILE* fmemopen_unlocked(void *buf, size_t size, const char *mode) { |
| FILE *f = fmemopen(buf, size, mode); |
| if (!f) |
| return NULL; |
| |
| (void) __fsetlocking(f, FSETLOCKING_BYCALLER); |
| |
| return f; |
| } |
| |
| int write_string_stream_ts( |
| FILE *f, |
| const char *line, |
| WriteStringFileFlags flags, |
| const struct timespec *ts) { |
| |
| bool needs_nl; |
| int r, fd = -EBADF; |
| |
| assert(f); |
| assert(line); |
| |
| if (ferror(f)) |
| return -EIO; |
| |
| if (ts) { |
| /* If we shall set the timestamp we need the fd. But fmemopen() streams generally don't have |
| * an fd. Let's fail early in that case. */ |
| fd = fileno(f); |
| if (fd < 0) |
| return -EBADF; |
| } |
| |
| if (flags & WRITE_STRING_FILE_SUPPRESS_REDUNDANT_VIRTUAL) { |
| _cleanup_free_ char *t = NULL; |
| |
| /* If value to be written is same as that of the existing value, then suppress the write. */ |
| |
| if (fd < 0) { |
| fd = fileno(f); |
| if (fd < 0) |
| return -EBADF; |
| } |
| |
| /* Read an additional byte to detect cases where the prefix matches but the rest |
| * doesn't. Also, 0 returned by read_virtual_file_fd() means the read was truncated and |
| * it won't be equal to the new value. */ |
| if (read_virtual_file_fd(fd, strlen(line)+1, &t, NULL) > 0 && |
| streq_skip_trailing_chars(line, t, NEWLINE)) { |
| log_debug("No change in value '%s', suppressing write", line); |
| return 0; |
| } |
| |
| if (lseek(fd, 0, SEEK_SET) < 0) |
| return -errno; |
| } |
| |
| needs_nl = !(flags & WRITE_STRING_FILE_AVOID_NEWLINE) && !endswith(line, "\n"); |
| |
| if (needs_nl && (flags & WRITE_STRING_FILE_DISABLE_BUFFER)) { |
| /* If STDIO buffering was disabled, then let's append the newline character to the string |
| * itself, so that the write goes out in one go, instead of two */ |
| |
| line = strjoina(line, "\n"); |
| needs_nl = false; |
| } |
| |
| if (fputs(line, f) == EOF) |
| return -errno; |
| |
| if (needs_nl) |
| if (fputc('\n', f) == EOF) |
| return -errno; |
| |
| if (flags & WRITE_STRING_FILE_SYNC) |
| r = fflush_sync_and_check(f); |
| else |
| r = fflush_and_check(f); |
| if (r < 0) |
| return r; |
| |
| if (ts) { |
| const struct timespec twice[2] = {*ts, *ts}; |
| |
| assert(fd >= 0); |
| if (futimens(fd, twice) < 0) |
| return -errno; |
| } |
| |
| return 0; |
| } |
| |
| static int write_string_file_atomic_at( |
| int dir_fd, |
| const char *fn, |
| const char *line, |
| WriteStringFileFlags flags, |
| const struct timespec *ts) { |
| |
| _cleanup_fclose_ FILE *f = NULL; |
| _cleanup_free_ char *p = NULL; |
| int r; |
| |
| 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_at(dir_fd, fn, &f, &p); |
| if (r < 0) |
| return r; |
| |
| 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 (renameat(dir_fd, p, dir_fd, fn) < 0) { |
| r = -errno; |
| goto fail; |
| } |
| |
| if (FLAGS_SET(flags, WRITE_STRING_FILE_SYNC)) { |
| /* Sync the rename, too */ |
| r = fsync_directory_of_file(fileno(f)); |
| if (r < 0) |
| return r; |
| } |
| |
| return 0; |
| |
| fail: |
| (void) unlinkat(dir_fd, p, 0); |
| return r; |
| } |
| |
| int write_string_file_ts_at( |
| int dir_fd, |
| const char *fn, |
| const char *line, |
| WriteStringFileFlags flags, |
| const struct timespec *ts) { |
| |
| _cleanup_fclose_ FILE *f = NULL; |
| int q, r, fd; |
| |
| assert(fn); |
| assert(line); |
| |
| /* We don't know how to verify whether the file contents was already on-disk. */ |
| assert(!((flags & WRITE_STRING_FILE_VERIFY_ON_FAILURE) && (flags & WRITE_STRING_FILE_SYNC))); |
| |
| if (flags & WRITE_STRING_FILE_MKDIR_0755) { |
| r = mkdirat_parents(dir_fd, fn, 0755); |
| if (r < 0) |
| return r; |
| } |
| |
| if (flags & WRITE_STRING_FILE_ATOMIC) { |
| assert(flags & WRITE_STRING_FILE_CREATE); |
| |
| r = write_string_file_atomic_at(dir_fd, fn, line, flags, ts); |
| if (r < 0) |
| goto fail; |
| |
| return r; |
| } else |
| assert(!ts); |
| |
| /* We manually build our own version of fopen(..., "we") that works without O_CREAT and with O_NOFOLLOW if needed. */ |
| fd = openat(dir_fd, fn, 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_TRUNCATE) ? O_TRUNC : 0) | |
| (FLAGS_SET(flags, WRITE_STRING_FILE_SUPPRESS_REDUNDANT_VIRTUAL) ? O_RDWR : O_WRONLY), |
| (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; |
| } |
| |
| if (flags & WRITE_STRING_FILE_DISABLE_BUFFER) |
| setvbuf(f, NULL, _IONBF, 0); |
| |
| r = write_string_stream_ts(f, line, flags, ts); |
| if (r < 0) |
| goto fail; |
| |
| return 0; |
| |
| fail: |
| if (!(flags & WRITE_STRING_FILE_VERIFY_ON_FAILURE)) |
| return r; |
| |
| f = safe_fclose(f); |
| |
| /* OK, the operation failed, but let's see if the right |
| * contents in place already. If so, eat up the error. */ |
| |
| q = verify_file(fn, line, !(flags & WRITE_STRING_FILE_AVOID_NEWLINE) || (flags & WRITE_STRING_FILE_VERIFY_IGNORE_NEWLINE)); |
| if (q <= 0) |
| return r; |
| |
| return 0; |
| } |
| |
| int write_string_filef( |
| const char *fn, |
| WriteStringFileFlags flags, |
| const char *format, ...) { |
| |
| _cleanup_free_ char *p = NULL; |
| va_list ap; |
| int r; |
| |
| va_start(ap, format); |
| r = vasprintf(&p, format, ap); |
| va_end(ap); |
| |
| if (r < 0) |
| return -ENOMEM; |
| |
| return write_string_file(fn, p, flags); |
| } |
| |
| int read_one_line_file(const char *fn, char **line) { |
| _cleanup_fclose_ FILE *f = NULL; |
| int r; |
| |
| assert(fn); |
| assert(line); |
| |
| r = fopen_unlocked(fn, "re", &f); |
| if (r < 0) |
| return r; |
| |
| return read_line(f, LONG_LINE_MAX, line); |
| } |
| |
| int verify_file_at(int dir_fd, const char *fn, const char *blob, bool accept_extra_nl) { |
| _cleanup_fclose_ FILE *f = NULL; |
| _cleanup_free_ char *buf = NULL; |
| size_t l, k; |
| int r; |
| |
| assert(fn); |
| assert(blob); |
| |
| l = strlen(blob); |
| |
| if (accept_extra_nl && endswith(blob, "\n")) |
| accept_extra_nl = false; |
| |
| buf = malloc(l + accept_extra_nl + 1); |
| if (!buf) |
| return -ENOMEM; |
| |
| r = fopen_unlocked_at(dir_fd, fn, "re", 0, &f); |
| if (r < 0) |
| return r; |
| |
| /* We try to read one byte more than we need, so that we know whether we hit eof */ |
| errno = 0; |
| k = fread(buf, 1, l + accept_extra_nl + 1, f); |
| if (ferror(f)) |
| return errno_or_else(EIO); |
| |
| if (k != l && k != l + accept_extra_nl) |
| return 0; |
| if (memcmp(buf, blob, l) != 0) |
| return 0; |
| if (k > l && buf[l] != '\n') |
| return 0; |
| |
| return 1; |
| } |
| |
| int read_virtual_file_fd(int fd, size_t max_size, char **ret_contents, size_t *ret_size) { |
| _cleanup_free_ char *buf = NULL; |
| size_t n, size; |
| int n_retries; |
| bool truncated = false; |
| |
| /* Virtual filesystems such as sysfs or procfs use kernfs, and kernfs can work with two sorts of |
| * virtual files. One sort uses "seq_file", and the results of the first read are buffered for the |
| * second read. The other sort uses "raw" reads which always go direct to the device. In the latter |
| * case, the content of the virtual file must be retrieved with a single read otherwise a second read |
| * might get the new value instead of finding EOF immediately. That's the reason why the usage of |
| * fread(3) is prohibited in this case as it always performs a second call to read(2) looking for |
| * EOF. See issue #13585. |
| * |
| * max_size specifies a limit on the bytes read. If max_size is SIZE_MAX, the full file is read. If |
| * the full file is too large to read, an error is returned. For other values of max_size, *partial |
| * contents* may be returned. (Though the read is still done using one syscall.) Returns 0 on |
| * partial success, 1 if untruncated contents were read. */ |
| |
| assert(fd >= 0); |
| assert(max_size <= READ_VIRTUAL_BYTES_MAX || max_size == SIZE_MAX); |
| |
| /* Limit the number of attempts to read the number of bytes returned by fstat(). */ |
| n_retries = 3; |
| |
| for (;;) { |
| struct stat st; |
| |
| if (fstat(fd, &st) < 0) |
| return -errno; |
| |
| if (!S_ISREG(st.st_mode)) |
| return -EBADF; |
| |
| /* Be prepared for files from /proc which generally report a file size of 0. */ |
| assert_cc(READ_VIRTUAL_BYTES_MAX < SSIZE_MAX); |
| if (st.st_size > 0 && n_retries > 1) { |
| /* Let's use the file size if we have more than 1 attempt left. On the last attempt |
| * we'll ignore the file size */ |
| |
| if (st.st_size > SSIZE_MAX) { /* Avoid overflow with 32-bit size_t and 64-bit off_t. */ |
| |
| if (max_size == SIZE_MAX) |
| return -EFBIG; |
| |
| size = max_size; |
| } else { |
| size = MIN((size_t) st.st_size, max_size); |
| |
| if (size > READ_VIRTUAL_BYTES_MAX) |
| return -EFBIG; |
| } |
| |
| n_retries--; |
| } else if (n_retries > 1) { |
| /* Files in /proc are generally smaller than the page size so let's start with |
| * a page size buffer from malloc and only use the max buffer on the final try. */ |
| size = MIN3(page_size() - 1, READ_VIRTUAL_BYTES_MAX, max_size); |
| n_retries = 1; |
| } else { |
| size = MIN(READ_VIRTUAL_BYTES_MAX, max_size); |
| n_retries = 0; |
| } |
| |
| buf = malloc(size + 1); |
| if (!buf) |
| return -ENOMEM; |
| |
| /* Use a bigger allocation if we got it anyway, but not more than the limit. */ |
| size = MIN3(MALLOC_SIZEOF_SAFE(buf) - 1, max_size, READ_VIRTUAL_BYTES_MAX); |
| |
| for (;;) { |
| ssize_t k; |
| |
| /* Read one more byte so we can detect whether the content of the |
| * file has already changed or the guessed size for files from /proc |
| * wasn't large enough . */ |
| k = read(fd, buf, size + 1); |
| if (k >= 0) { |
| n = k; |
| break; |
| } |
| |
| if (errno != EINTR) |
| return -errno; |
| } |
| |
| /* Consider a short read as EOF */ |
| if (n <= size) |
| break; |
| |
| /* If a maximum size is specified and we already read more we know the file is larger, and |
| * can handle this as truncation case. Note that if the size of what we read equals the |
| * maximum size then this doesn't mean truncation, the file might or might not end on that |
| * byte. We need to rerun the loop in that case, with a larger buffer size, so that we read |
| * at least one more byte to be able to distinguish EOF from truncation. */ |
| if (max_size != SIZE_MAX && n > max_size) { |
| n = size; /* Make sure we never use more than what we sized the buffer for (so that |
| * we have one free byte in it for the trailing NUL we add below). */ |
| truncated = true; |
| break; |
| } |
| |
| /* We have no further attempts left? Then the file is apparently larger than our limits. Give up. */ |
| if (n_retries <= 0) |
| return -EFBIG; |
| |
| /* Hmm... either we read too few bytes from /proc or less likely the content of the file |
| * might have been changed (and is now bigger) while we were processing, let's try again |
| * either with the new file size. */ |
| |
| if (lseek(fd, 0, SEEK_SET) < 0) |
| return -errno; |
| |
| buf = mfree(buf); |
| } |
| |
| if (ret_contents) { |
| |
| /* Safety check: if the caller doesn't want to know the size of what we just read it will |
| * rely on the trailing NUL byte. But if there's an embedded NUL byte, then we should refuse |
| * operation as otherwise there'd be ambiguity about what we just read. */ |
| if (!ret_size && memchr(buf, 0, n)) |
| return -EBADMSG; |
| |
| if (n < size) { |
| char *p; |
| |
| /* Return rest of the buffer to libc */ |
| p = realloc(buf, n + 1); |
| if (!p) |
| return -ENOMEM; |
| buf = p; |
| } |
| |
| buf[n] = 0; |
| *ret_contents = TAKE_PTR(buf); |
| } |
| |
| if (ret_size) |
| *ret_size = n; |
| |
| return !truncated; |
| } |
| |
| int read_virtual_file_at( |
| int dir_fd, |
| const char *filename, |
| size_t max_size, |
| char **ret_contents, |
| size_t *ret_size) { |
| |
| _cleanup_close_ int fd = -EBADF; |
| |
| assert(dir_fd >= 0 || dir_fd == AT_FDCWD); |
| |
| if (!filename) { |
| if (dir_fd == AT_FDCWD) |
| return -EBADF; |
| |
| return read_virtual_file_fd(dir_fd, max_size, ret_contents, ret_size); |
| } |
| |
| fd = openat(dir_fd, filename, O_RDONLY | O_NOCTTY | O_CLOEXEC); |
| if (fd < 0) |
| return -errno; |
| |
| return read_virtual_file_fd(fd, max_size, ret_contents, ret_size); |
| } |
| |
| int read_full_stream_full( |
| FILE *f, |
| const char *filename, |
| uint64_t offset, |
| size_t size, |
| ReadFullFileFlags flags, |
| char **ret_contents, |
| size_t *ret_size) { |
| |
| _cleanup_free_ char *buf = NULL; |
| size_t n, n_next = 0, l; |
| int fd, r; |
| |
| assert(f); |
| assert(ret_contents); |
| assert(!FLAGS_SET(flags, READ_FULL_FILE_UNBASE64 | READ_FULL_FILE_UNHEX)); |
| assert(size != SIZE_MAX || !FLAGS_SET(flags, READ_FULL_FILE_FAIL_WHEN_LARGER)); |
| |
| if (offset != UINT64_MAX && offset > LONG_MAX) /* fseek() can only deal with "long" offsets */ |
| return -ERANGE; |
| |
| fd = fileno(f); |
| if (fd >= 0) { /* If the FILE* object is backed by an fd (as opposed to memory or such, see |
| * fmemopen()), let's optimize our buffering */ |
| struct stat st; |
| |
| if (fstat(fd, &st) < 0) |
| return -errno; |
| |
| if (S_ISREG(st.st_mode)) { |
| |
| /* Try to start with the right file size if we shall read the file in full. Note |
| * that we increase the size to read here by one, so that the first read attempt |
| * already makes us notice the EOF. If the reported size of the file is zero, we |
| * avoid this logic however, since quite likely it might be a virtual file in procfs |
| * that all report a zero file size. */ |
| |
| if (st.st_size > 0 && |
| (size == SIZE_MAX || FLAGS_SET(flags, READ_FULL_FILE_FAIL_WHEN_LARGER))) { |
| |
| uint64_t rsize = |
| LESS_BY((uint64_t) st.st_size, offset == UINT64_MAX ? 0 : offset); |
| |
| if (rsize < SIZE_MAX) /* overflow check */ |
| n_next = rsize + 1; |
| } |
| |
| if (flags & READ_FULL_FILE_WARN_WORLD_READABLE) |
| (void) warn_file_is_world_accessible(filename, &st, NULL, 0); |
| } |
| } |
| |
| /* If we don't know how much to read, figure it out now. If we shall read a part of the file, then |
| * allocate the requested size. If we shall load the full file start with LINE_MAX. Note that if |
| * READ_FULL_FILE_FAIL_WHEN_LARGER we consider the specified size a safety limit, and thus also start |
| * with LINE_MAX, under assumption the file is most likely much shorter. */ |
| if (n_next == 0) |
| n_next = size != SIZE_MAX && !FLAGS_SET(flags, READ_FULL_FILE_FAIL_WHEN_LARGER) ? size : LINE_MAX; |
| |
| /* Never read more than we need to determine that our own limit is hit */ |
| if (n_next > READ_FULL_BYTES_MAX) |
| n_next = READ_FULL_BYTES_MAX + 1; |
| |
| if (offset != UINT64_MAX && fseek(f, offset, SEEK_SET) < 0) |
| return -errno; |
| |
| n = l = 0; |
| for (;;) { |
| char *t; |
| size_t k; |
| |
| /* If we shall fail when reading overly large data, then read exactly one byte more than the |
| * specified size at max, since that'll tell us if there's anymore data beyond the limit*/ |
| if (FLAGS_SET(flags, READ_FULL_FILE_FAIL_WHEN_LARGER) && n_next > size) |
| n_next = size + 1; |
| |
| if (flags & READ_FULL_FILE_SECURE) { |
| t = malloc(n_next + 1); |
| if (!t) { |
| r = -ENOMEM; |
| goto finalize; |
| } |
| memcpy_safe(t, buf, n); |
| explicit_bzero_safe(buf, n); |
| free(buf); |
| } else { |
| t = realloc(buf, n_next + 1); |
| if (!t) |
| return -ENOMEM; |
| } |
| |
| buf = t; |
| /* Unless a size has been explicitly specified, try to read as much as fits into the memory |
| * we allocated (minus 1, to leave one byte for the safety NUL byte) */ |
| n = size == SIZE_MAX ? MALLOC_SIZEOF_SAFE(buf) - 1 : n_next; |
| |
| errno = 0; |
| k = fread(buf + l, 1, n - l, f); |
| |
| assert(k <= n - l); |
| l += k; |
| |
| if (ferror(f)) { |
| r = errno_or_else(EIO); |
| goto finalize; |
| } |
| if (feof(f)) |
| break; |
| |
| if (size != SIZE_MAX && !FLAGS_SET(flags, READ_FULL_FILE_FAIL_WHEN_LARGER)) { /* If we got asked to read some specific size, we already sized the buffer right, hence leave */ |
| assert(l == size); |
| break; |
| } |
| |
| assert(k > 0); /* we can't have read zero bytes because that would have been EOF */ |
| |
| if (FLAGS_SET(flags, READ_FULL_FILE_FAIL_WHEN_LARGER) && l > size) { |
| r = -E2BIG; |
| goto finalize; |
| } |
| |
| if (n >= READ_FULL_BYTES_MAX) { |
| r = -E2BIG; |
| goto finalize; |
| } |
| |
| n_next = MIN(n * 2, READ_FULL_BYTES_MAX); |
| } |
| |
| if (flags & (READ_FULL_FILE_UNBASE64 | READ_FULL_FILE_UNHEX)) { |
| _cleanup_free_ void *decoded = NULL; |
| size_t decoded_size; |
| |
| buf[l++] = 0; |
| if (flags & READ_FULL_FILE_UNBASE64) |
| r = unbase64mem_full(buf, l, flags & READ_FULL_FILE_SECURE, &decoded, &decoded_size); |
| else |
| r = unhexmem_full(buf, l, flags & READ_FULL_FILE_SECURE, &decoded, &decoded_size); |
| if (r < 0) |
| goto finalize; |
| |
| if (flags & READ_FULL_FILE_SECURE) |
| explicit_bzero_safe(buf, n); |
| free_and_replace(buf, decoded); |
| n = l = decoded_size; |
| } |
| |
| if (!ret_size) { |
| /* Safety check: if the caller doesn't want to know the size of what we just read it will rely on the |
| * trailing NUL byte. But if there's an embedded NUL byte, then we should refuse operation as otherwise |
| * there'd be ambiguity about what we just read. */ |
| |
| if (memchr(buf, 0, l)) { |
| r = -EBADMSG; |
| goto finalize; |
| } |
| } |
| |
| buf[l] = 0; |
| *ret_contents = TAKE_PTR(buf); |
| |
| if (ret_size) |
| *ret_size = l; |
| |
| return 0; |
| |
| finalize: |
| if (flags & READ_FULL_FILE_SECURE) |
| explicit_bzero_safe(buf, n); |
| |
| return r; |
| } |
| |
| int read_full_file_full( |
| int dir_fd, |
| const char *filename, |
| uint64_t offset, |
| size_t size, |
| ReadFullFileFlags flags, |
| const char *bind_name, |
| char **ret_contents, |
| size_t *ret_size) { |
| |
| _cleanup_fclose_ FILE *f = NULL; |
| int r; |
| |
| assert(filename); |
| assert(ret_contents); |
| |
| r = xfopenat(dir_fd, filename, "re", 0, &f); |
| if (r < 0) { |
| _cleanup_close_ int sk = -EBADF; |
| |
| /* ENXIO is what Linux returns if we open a node that is an AF_UNIX socket */ |
| if (r != -ENXIO) |
| return r; |
| |
| /* If this is enabled, let's try to connect to it */ |
| if (!FLAGS_SET(flags, READ_FULL_FILE_CONNECT_SOCKET)) |
| return -ENXIO; |
| |
| /* Seeking is not supported on AF_UNIX sockets */ |
| if (offset != UINT64_MAX) |
| return -ENXIO; |
| |
| sk = socket(AF_UNIX, SOCK_STREAM|SOCK_CLOEXEC, 0); |
| if (sk < 0) |
| return -errno; |
| |
| if (bind_name) { |
| /* If the caller specified a socket name to bind to, do so before connecting. This is |
| * useful to communicate some minor, short meta-information token from the client to |
| * the server. */ |
| union sockaddr_union bsa; |
| |
| r = sockaddr_un_set_path(&bsa.un, bind_name); |
| if (r < 0) |
| return r; |
| |
| if (bind(sk, &bsa.sa, r) < 0) |
| return -errno; |
| } |
| |
| r = connect_unix_path(sk, dir_fd, filename); |
| if (IN_SET(r, -ENOTSOCK, -EINVAL)) /* propagate original error if this is not a socket after all */ |
| return -ENXIO; |
| if (r < 0) |
| return r; |
| |
| if (shutdown(sk, SHUT_WR) < 0) |
| return -errno; |
| |
| f = fdopen(sk, "r"); |
| if (!f) |
| return -errno; |
| |
| TAKE_FD(sk); |
| } |
| |
| (void) __fsetlocking(f, FSETLOCKING_BYCALLER); |
| |
| return read_full_stream_full(f, filename, offset, size, flags, ret_contents, ret_size); |
| } |
| |
| int executable_is_script(const char *path, char **interpreter) { |
| _cleanup_free_ char *line = NULL; |
| size_t len; |
| char *ans; |
| int r; |
| |
| assert(path); |
| |
| r = read_one_line_file(path, &line); |
| if (r == -ENOBUFS) /* First line overly long? if so, then it's not a script */ |
| return 0; |
| if (r < 0) |
| return r; |
| |
| if (!startswith(line, "#!")) |
| return 0; |
| |
| ans = strstrip(line + 2); |
| len = strcspn(ans, " \t"); |
| |
| if (len == 0) |
| return 0; |
| |
| ans = strndup(ans, len); |
| if (!ans) |
| return -ENOMEM; |
| |
| *interpreter = ans; |
| return 1; |
| } |
| |
| /** |
| * Retrieve one field from a file like /proc/self/status. pattern |
| * should not include whitespace or the delimiter (':'). pattern matches only |
| * the beginning of a line. Whitespace before ':' is skipped. Whitespace and |
| * zeros after the ':' will be skipped. field must be freed afterwards. |
| * terminator specifies the terminating characters of the field value (not |
| * included in the value). |
| */ |
| int get_proc_field(const char *filename, const char *pattern, const char *terminator, char **field) { |
| _cleanup_free_ char *status = NULL; |
| char *t, *f; |
| int r; |
| |
| assert(terminator); |
| assert(filename); |
| assert(pattern); |
| assert(field); |
| |
| r = read_full_virtual_file(filename, &status, NULL); |
| if (r < 0) |
| return r; |
| |
| t = status; |
| |
| do { |
| bool pattern_ok; |
| |
| do { |
| t = strstr(t, pattern); |
| if (!t) |
| return -ENOENT; |
| |
| /* Check that pattern occurs in beginning of line. */ |
| pattern_ok = (t == status || t[-1] == '\n'); |
| |
| t += strlen(pattern); |
| |
| } while (!pattern_ok); |
| |
| t += strspn(t, " \t"); |
| if (!*t) |
| return -ENOENT; |
| |
| } while (*t != ':'); |
| |
| t++; |
| |
| if (*t) { |
| t += strspn(t, " \t"); |
| |
| /* Also skip zeros, because when this is used for |
| * capabilities, we don't want the zeros. This way the |
| * same capability set always maps to the same string, |
| * irrespective of the total capability set size. For |
| * other numbers it shouldn't matter. */ |
| t += strspn(t, "0"); |
| /* Back off one char if there's nothing but whitespace |
| and zeros */ |
| if (!*t || isspace(*t)) |
| t--; |
| } |
| |
| f = strdupcspn(t, terminator); |
| if (!f) |
| return -ENOMEM; |
| |
| *field = f; |
| return 0; |
| } |
| |
| DIR *xopendirat(int fd, const char *name, int flags) { |
| int nfd; |
| DIR *d; |
| |
| assert(!(flags & O_CREAT)); |
| |
| if (fd == AT_FDCWD && flags == 0) |
| return opendir(name); |
| |
| nfd = openat(fd, name, O_RDONLY|O_NONBLOCK|O_DIRECTORY|O_CLOEXEC|flags, 0); |
| if (nfd < 0) |
| return NULL; |
| |
| d = fdopendir(nfd); |
| if (!d) { |
| safe_close(nfd); |
| return NULL; |
| } |
| |
| return d; |
| } |
| |
| int fopen_mode_to_flags(const char *mode) { |
| const char *p; |
| int flags; |
| |
| assert(mode); |
| |
| 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 = fopen_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; |
| } |
| |
| static int search_and_fopen_internal( |
| const char *path, |
| const char *mode, |
| const char *root, |
| char **search, |
| FILE **ret, |
| char **ret_path) { |
| |
| assert(path); |
| assert(mode); |
| assert(ret); |
| |
| if (!path_strv_resolve_uniq(search, root)) |
| return -ENOMEM; |
| |
| STRV_FOREACH(i, search) { |
| _cleanup_free_ char *p = NULL; |
| FILE *f; |
| |
| p = path_join(root, *i, path); |
| if (!p) |
| return -ENOMEM; |
| |
| f = fopen(p, mode); |
| if (f) { |
| if (ret_path) |
| *ret_path = path_simplify(TAKE_PTR(p)); |
| |
| *ret = f; |
| return 0; |
| } |
| |
| if (errno != ENOENT) |
| return -errno; |
| } |
| |
| return -ENOENT; |
| } |
| |
| int search_and_fopen( |
| const char *filename, |
| const char *mode, |
| const char *root, |
| const char **search, |
| FILE **ret, |
| char **ret_path) { |
| |
| _cleanup_strv_free_ char **copy = NULL; |
| |
| assert(filename); |
| assert(mode); |
| assert(ret); |
| |
| if (path_is_absolute(filename)) { |
| _cleanup_fclose_ FILE *f = NULL; |
| |
| f = fopen(filename, mode); |
| if (!f) |
| return -errno; |
| |
| if (ret_path) { |
| char *p; |
| |
| p = strdup(filename); |
| if (!p) |
| return -ENOMEM; |
| |
| *ret_path = path_simplify(p); |
| } |
| |
| *ret = TAKE_PTR(f); |
| return 0; |
| } |
| |
| copy = strv_copy((char**) search); |
| if (!copy) |
| return -ENOMEM; |
| |
| return search_and_fopen_internal(filename, mode, root, copy, ret, ret_path); |
| } |
| |
| int search_and_fopen_nulstr( |
| const char *filename, |
| const char *mode, |
| const char *root, |
| const char *search, |
| FILE **ret, |
| char **ret_path) { |
| |
| _cleanup_strv_free_ char **s = NULL; |
| |
| if (path_is_absolute(filename)) { |
| _cleanup_fclose_ FILE *f = NULL; |
| |
| f = fopen(filename, mode); |
| if (!f) |
| return -errno; |
| |
| if (ret_path) { |
| char *p; |
| |
| p = strdup(filename); |
| if (!p) |
| return -ENOMEM; |
| |
| *ret_path = path_simplify(p); |
| } |
| |
| *ret = TAKE_PTR(f); |
| return 0; |
| } |
| |
| s = strv_split_nulstr(search); |
| if (!s) |
| return -ENOMEM; |
| |
| return search_and_fopen_internal(filename, mode, root, s, ret, ret_path); |
| } |
| |
| int fflush_and_check(FILE *f) { |
| assert(f); |
| |
| errno = 0; |
| fflush(f); |
| |
| if (ferror(f)) |
| return errno_or_else(EIO); |
| |
| return 0; |
| } |
| |
| int fflush_sync_and_check(FILE *f) { |
| int r, fd; |
| |
| assert(f); |
| |
| r = fflush_and_check(f); |
| if (r < 0) |
| return r; |
| |
| /* Not all file streams have an fd associated (think: fmemopen()), let's handle this gracefully and |
| * assume that in that case we need no explicit syncing */ |
| fd = fileno(f); |
| if (fd < 0) |
| return 0; |
| |
| r = fsync_full(fd); |
| 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 (!timestamp_is_set(n)) |
| 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 (!timestamp_is_set(t)) |
| 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 (!FLAGS_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_FULL(FILE*, funlockfile, NULL); |
| |
| int read_line_full(FILE *f, size_t limit, ReadLineFlags flags, char **ret) { |
| _cleanup_free_ char *buffer = NULL; |
| size_t n = 0, count = 0; |
| 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, 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) { |
| /* If we are on a tty, we can't shouldn't wait for more input, because that |
| * generally means waiting for the user, interactively. In the case of a TTY |
| * we expect only \n as the single EOL marker, so we are in the lucky |
| * position that there is no need to wait. We check this condition last, to |
| * avoid isatty() check if not necessary. */ |
| |
| if ((flags & (READ_LINE_IS_A_TTY|READ_LINE_NOT_A_TTY)) == 0) { |
| int fd; |
| |
| fd = fileno(f); |
| if (fd < 0) /* Maybe an fmemopen() stream? Handle this gracefully, |
| * and don't call isatty() on an invalid fd */ |
| flags |= READ_LINE_NOT_A_TTY; |
| else |
| flags |= isatty(fd) ? READ_LINE_IS_A_TTY : READ_LINE_NOT_A_TTY; |
| } |
| if (FLAGS_SET(flags, READ_LINE_IS_A_TTY)) |
| break; |
| } |
| |
| if (eol != EOL_NONE) { |
| previous_eol |= eol; |
| continue; |
| } |
| |
| if (ret) { |
| if (!GREEDY_REALLOC(buffer, 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_or_else(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 ownership and access mode.", |
| filename, st->st_mode & 07777); |
| else |
| log_warning("%s has %04o mode that is too permissive, please adjust the ownership and access mode.", |
| filename, st->st_mode & 07777); |
| return 0; |
| } |
