diff options
Diffstat (limited to 'src/systemd/src/basic/fileio.c')
| -rw-r--r-- | src/systemd/src/basic/fileio.c | 439 |
1 files changed, 420 insertions, 19 deletions
diff --git a/src/systemd/src/basic/fileio.c b/src/systemd/src/basic/fileio.c index 6246bc9598..e02d79c64d 100644 --- a/src/systemd/src/basic/fileio.c +++ b/src/systemd/src/basic/fileio.c @@ -23,11 +23,24 @@ #include <unistd.h> -#include "util.h" -#include "strv.h" -#include "utf8.h" +#include "alloc-util.h" #include "ctype.h" +#include "escape.h" +#include "fd-util.h" #include "fileio.h" +#include "fs-util.h" +#include "hexdecoct.h" +#include "parse-util.h" +#include "path-util.h" +#include "random-util.h" +#if 0 /* NM_IGNORED */ +#include "stdio-util.h" +#endif /* NM_IGNORED */ +#include "string-util.h" +#include "strv.h" +#include "umask-util.h" +#include "utf8.h" +#include "util.h" int write_string_stream(FILE *f, const char *line, bool enforce_newline) { @@ -53,7 +66,7 @@ static int write_string_file_atomic(const char *fn, const char *line, bool enfor if (r < 0) return r; - fchmod_umask(fileno(f), 0644); + (void) fchmod_umask(fileno(f), 0644); r = write_string_stream(f, line, enforce_newline); if (r >= 0) { @@ -62,13 +75,14 @@ static int write_string_file_atomic(const char *fn, const char *line, bool enfor } if (r < 0) - unlink(p); + (void) unlink(p); return r; } int write_string_file(const char *fn, const char *line, WriteStringFileFlags flags) { _cleanup_fclose_ FILE *f = NULL; + int q, r; assert(fn); assert(line); @@ -76,30 +90,58 @@ int write_string_file(const char *fn, const char *line, WriteStringFileFlags fla if (flags & WRITE_STRING_FILE_ATOMIC) { assert(flags & WRITE_STRING_FILE_CREATE); - return write_string_file_atomic(fn, line, !(flags & WRITE_STRING_FILE_AVOID_NEWLINE)); + r = write_string_file_atomic(fn, line, !(flags & WRITE_STRING_FILE_AVOID_NEWLINE)); + if (r < 0) + goto fail; + + return r; } if (flags & WRITE_STRING_FILE_CREATE) { f = fopen(fn, "we"); - if (!f) - return -errno; + if (!f) { + r = -errno; + 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); - if (fd < 0) - return -errno; + if (fd < 0) { + r = -errno; + goto fail; + } f = fdopen(fd, "we"); if (!f) { + r = -errno; safe_close(fd); - return -errno; + goto fail; } } - return write_string_stream(f, line, !(flags & WRITE_STRING_FILE_AVOID_NEWLINE)); + r = write_string_stream(f, line, !(flags & WRITE_STRING_FILE_AVOID_NEWLINE)); + 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)); + if (q <= 0) + return r; + + return 0; } int read_one_line_file(const char *fn, char **line) { @@ -130,15 +172,41 @@ int read_one_line_file(const char *fn, char **line) { return 0; } -int verify_one_line_file(const char *fn, const char *line) { - _cleanup_free_ char *value = NULL; - int r; +int verify_file(const char *fn, const char *blob, bool accept_extra_nl) { + _cleanup_fclose_ FILE *f = NULL; + _cleanup_free_ char *buf = NULL; + size_t l, k; - r = read_one_line_file(fn, &value); - if (r < 0) - return 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; - return streq(value, line); + f = fopen(fn, "re"); + if (!f) + return -errno; + + /* 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 > 0 ? -errno : -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_full_stream(FILE *f, char **contents, size_t *size) { @@ -847,3 +915,336 @@ int get_proc_field(const char *filename, const char *pattern, const char *termin *field = f; return 0; } + +DIR *xopendirat(int fd, const char *name, int flags) { + int nfd; + DIR *d; + + assert(!(flags & O_CREAT)); + + 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; +} + +#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; + + assert(path); + assert(mode); + assert(_f); + + if (!path_strv_resolve_uniq(search, root)) + return -ENOMEM; + + STRV_FOREACH(i, search) { + _cleanup_free_ char *p = NULL; + FILE *f; + + if (root) + p = strjoin(root, *i, "/", path, NULL); + else + p = strjoin(*i, "/", path, NULL); + if (!p) + return -ENOMEM; + + f = fopen(p, mode); + if (f) { + *_f = f; + return 0; + } + + if (errno != ENOENT) + return -errno; + } + + return -ENOENT; +} + +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); +} +#endif /* NM_IGNORED */ + +int fopen_temporary(const char *path, FILE **_f, char **_temp_path) { + FILE *f; + char *t; + int r, fd; + + assert(path); + assert(_f); + assert(_temp_path); + + r = tempfn_xxxxxx(path, NULL, &t); + if (r < 0) + return r; + + fd = mkostemp_safe(t, O_WRONLY|O_CLOEXEC); + if (fd < 0) { + free(t); + return -errno; + } + + f = fdopen(fd, "we"); + if (!f) { + unlink_noerrno(t); + free(t); + safe_close(fd); + return -errno; + } + + *_f = f; + *_temp_path = t; + + return 0; +} + +int fflush_and_check(FILE *f) { + assert(f); + + errno = 0; + fflush(f); + + if (ferror(f)) + return errno ? -errno : -EIO; + + return 0; +} + +/* This is much like like mkostemp() but is subject to umask(). */ +int mkostemp_safe(char *pattern, int flags) { + _cleanup_umask_ mode_t u; + int fd; + + assert(pattern); + + u = umask(077); + + fd = mkostemp(pattern, flags); + if (fd < 0) + return -errno; + + return fd; +} + +int open_tmpfile(const char *path, int flags) { + char *p; + int fd; + + assert(path); + +#ifdef O_TMPFILE + /* Try O_TMPFILE first, if it is supported */ + fd = open(path, flags|O_TMPFILE|O_EXCL, S_IRUSR|S_IWUSR); + if (fd >= 0) + return fd; +#endif + + /* Fall back to unguessable name + unlinking */ + p = strjoina(path, "/systemd-tmp-XXXXXX"); + + fd = mkostemp_safe(p, flags); + if (fd < 0) + return fd; + + unlink(p); + return fd; +} + +int tempfn_xxxxxx(const char *p, const char *extra, char **ret) { + const char *fn; + char *t; + + assert(p); + assert(ret); + + /* + * Turns this: + * /foo/bar/waldo + * + * Into this: + * /foo/bar/.#<extra>waldoXXXXXX + */ + + fn = basename(p); + if (!filename_is_valid(fn)) + return -EINVAL; + + if (extra == NULL) + extra = ""; + + t = new(char, strlen(p) + 2 + strlen(extra) + 6 + 1); + if (!t) + return -ENOMEM; + + strcpy(stpcpy(stpcpy(stpcpy(mempcpy(t, p, fn - p), ".#"), extra), fn), "XXXXXX"); + + *ret = path_kill_slashes(t); + return 0; +} + +int tempfn_random(const char *p, const char *extra, char **ret) { + const char *fn; + char *t, *x; + uint64_t u; + unsigned i; + + assert(p); + assert(ret); + + /* + * Turns this: + * /foo/bar/waldo + * + * Into this: + * /foo/bar/.#<extra>waldobaa2a261115984a9 + */ + + fn = basename(p); + if (!filename_is_valid(fn)) + return -EINVAL; + + if (!extra) + extra = ""; + + t = new(char, strlen(p) + 2 + strlen(extra) + 16 + 1); + if (!t) + return -ENOMEM; + + x = stpcpy(stpcpy(stpcpy(mempcpy(t, p, fn - p), ".#"), extra), fn); + + u = random_u64(); + for (i = 0; i < 16; i++) { + *(x++) = hexchar(u & 0xF); + u >>= 4; + } + + *x = 0; + + *ret = path_kill_slashes(t); + return 0; +} + +int tempfn_random_child(const char *p, const char *extra, char **ret) { + char *t, *x; + uint64_t u; + unsigned i; + + assert(p); + assert(ret); + + /* Turns this: + * /foo/bar/waldo + * Into this: + * /foo/bar/waldo/.#<extra>3c2b6219aa75d7d0 + */ + + if (!extra) + extra = ""; + + t = new(char, strlen(p) + 3 + strlen(extra) + 16 + 1); + if (!t) + return -ENOMEM; + + x = stpcpy(stpcpy(stpcpy(t, p), "/.#"), extra); + + u = random_u64(); + for (i = 0; i < 16; i++) { + *(x++) = hexchar(u & 0xF); + u >>= 4; + } + + *x = 0; + + *ret = path_kill_slashes(t); + return 0; +} + +#if 0 /* NM_IGNORED */ +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); +} +#endif /* NM_IGNORED */ + +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; +} |