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-rw-r--r--src/basic/fileio.c697
1 files changed, 640 insertions, 57 deletions
diff --git a/src/basic/fileio.c b/src/basic/fileio.c
index d592bf5ac9..1cfb7a98f5 100644
--- a/src/basic/fileio.c
+++ b/src/basic/fileio.c
@@ -1,5 +1,3 @@
-/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
-
/***
This file is part of systemd.
@@ -19,30 +17,49 @@
along with systemd; If not, see <http://www.gnu.org/licenses/>.
***/
+#include <errno.h>
+#include <fcntl.h>
+#include <limits.h>
+#include <stdarg.h>
+#include <stdint.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/stat.h>
+#include <sys/types.h>
#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 "log.h"
+#include "macro.h"
+#include "missing.h"
+#include "parse-util.h"
+#include "path-util.h"
+#include "random-util.h"
+#include "stdio-util.h"
+#include "string-util.h"
+#include "strv.h"
+#include "time-util.h"
+#include "umask-util.h"
+#include "utf8.h"
+
+#define READ_FULL_BYTES_MAX (4U*1024U*1024U)
int write_string_stream(FILE *f, const char *line, bool enforce_newline) {
+
assert(f);
assert(line);
- errno = 0;
-
fputs(line, f);
if (enforce_newline && !endswith(line, "\n"))
fputc('\n', f);
- fflush(f);
-
- if (ferror(f))
- return errno ? -errno : -EIO;
-
- return 0;
+ return fflush_and_check(f);
}
static int write_string_file_atomic(const char *fn, const char *line, bool enforce_newline) {
@@ -57,7 +74,7 @@ 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) {
@@ -66,13 +83,14 @@ 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);
@@ -80,30 +98,58 @@ 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) {
@@ -120,7 +166,7 @@ int read_one_line_file(const char *fn, char **line) {
if (!fgets(t, sizeof(t), f)) {
if (ferror(f))
- return errno ? -errno : -EIO;
+ return errno > 0 ? -errno : -EIO;
t[0] = 0;
}
@@ -134,15 +180,41 @@ 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;
+
+ 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;
- return streq(value, line);
+ 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) {
@@ -161,7 +233,7 @@ int read_full_stream(FILE *f, char **contents, size_t *size) {
if (S_ISREG(st.st_mode)) {
/* Safety check */
- if (st.st_size > 4*1024*1024)
+ if (st.st_size > READ_FULL_BYTES_MAX)
return -E2BIG;
/* Start with the right file size, but be prepared for
@@ -176,26 +248,31 @@ int read_full_stream(FILE *f, char **contents, size_t *size) {
char *t;
size_t k;
- t = realloc(buf, n+1);
+ t = realloc(buf, n + 1);
if (!t)
return -ENOMEM;
buf = t;
k = fread(buf + l, 1, n - l, f);
+ if (k > 0)
+ l += k;
- if (k <= 0) {
- if (ferror(f))
- return -errno;
+ if (ferror(f))
+ return -errno;
+ if (feof(f))
break;
- }
- l += k;
- n *= 2;
+ /* We aren't expecting fread() to return a short read outside
+ * of (error && eof), assert buffer is full and enlarge buffer.
+ */
+ assert(l == n);
/* Safety check */
- if (n > 4*1024*1024)
+ if (n >= READ_FULL_BYTES_MAX)
return -E2BIG;
+
+ n = MIN(n * 2, READ_FULL_BYTES_MAX);
}
buf[l] = 0;
@@ -283,7 +360,7 @@ static int parse_env_file_internal(
case KEY:
if (strchr(newline, c)) {
state = PRE_KEY;
- line ++;
+ line++;
n_key = 0;
} else if (c == '=') {
state = PRE_VALUE;
@@ -307,7 +384,7 @@ static int parse_env_file_internal(
case PRE_VALUE:
if (strchr(newline, c)) {
state = PRE_KEY;
- line ++;
+ line++;
key[n_key] = 0;
if (value)
@@ -347,7 +424,7 @@ static int parse_env_file_internal(
case VALUE:
if (strchr(newline, c)) {
state = PRE_KEY;
- line ++;
+ line++;
key[n_key] = 0;
@@ -466,7 +543,7 @@ static int parse_env_file_internal(
state = COMMENT_ESCAPE;
else if (strchr(newline, c)) {
state = PRE_KEY;
- line ++;
+ line++;
}
break;
@@ -519,7 +596,7 @@ static int parse_env_file_push(
va_list aq, *ap = userdata;
if (!utf8_is_valid(key)) {
- _cleanup_free_ char *p;
+ _cleanup_free_ char *p = NULL;
p = utf8_escape_invalid(key);
log_error("%s:%u: invalid UTF-8 in key '%s', ignoring.", strna(filename), line, p);
@@ -527,7 +604,7 @@ static int parse_env_file_push(
}
if (value && !utf8_is_valid(value)) {
- _cleanup_free_ char *p;
+ _cleanup_free_ char *p = NULL;
p = utf8_escape_invalid(value);
log_error("%s:%u: invalid UTF-8 value for key %s: '%s', ignoring.", strna(filename), line, key, p);
@@ -781,15 +858,19 @@ int executable_is_script(const char *path, char **interpreter) {
/**
* Retrieve one field from a file like /proc/self/status. pattern
- * should start with '\n' and end with a ':'. Whitespace and zeros
- * after the ':' will be skipped. field must be freed afterwards.
+ * 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_status_field(const char *filename, const char *pattern, char **field) {
+int get_proc_field(const char *filename, const char *pattern, const char *terminator, char **field) {
_cleanup_free_ char *status = NULL;
- char *t;
+ char *t, *f;
size_t len;
int r;
+ assert(terminator);
assert(filename);
assert(pattern);
assert(field);
@@ -798,11 +879,31 @@ int get_status_field(const char *filename, const char *pattern, char **field) {
if (r < 0)
return r;
- t = strstr(status, pattern);
- if (!t)
- return -ENOENT;
+ 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++;
- t += strlen(pattern);
if (*t) {
t += strspn(t, " \t");
@@ -815,14 +916,496 @@ int get_status_field(const char *filename, const char *pattern, char **field) {
/* Back off one char if there's nothing but whitespace
and zeros */
if (!*t || isspace(*t))
- t --;
+ t--;
+ }
+
+ len = strcspn(t, terminator);
+
+ f = strndup(t, len);
+ 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));
+
+ 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;
+}
+
+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;
}
- len = strcspn(t, WHITESPACE);
+ 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;
- *field = strndup(t, len);
- if (!*field)
+ 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 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);
+ 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 > 0 ? -errno : -EIO;
+
+ return 0;
+}
+
+/* This is much like mkostemp() but is subject to umask(). */
+int mkostemp_safe(char *pattern) {
+ _cleanup_umask_ mode_t u = 0;
+ int fd;
+
+ assert(pattern);
+
+ u = umask(077);
+
+ fd = mkostemp(pattern, O_CLOEXEC);
+ if (fd < 0)
+ return -errno;
+
+ 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;
+ int r;
+
+ assert(ret);
+
+ /* Turns this:
+ * /foo/bar/waldo
+ * Into this:
+ * /foo/bar/waldo/.#<extra>3c2b6219aa75d7d0
+ */
+
+ if (!p) {
+ r = tmp_dir(&p);
+ if (r < 0)
+ return r;
+ }
+
+ 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;
+}
+
+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);
+}
+
+int open_tmpfile_unlinkable(const char *directory, int flags) {
+ char *p;
+ int fd, r;
+
+ if (!directory) {
+ r = tmp_dir(&directory);
+ if (r < 0)
+ return r;
+ }
+
+ /* Returns an unlinked temporary file that cannot be linked into the file system anymore */
+
+ /* Try O_TMPFILE first, if it is supported */
+ fd = open(directory, flags|O_TMPFILE|O_EXCL, S_IRUSR|S_IWUSR);
+ if (fd >= 0)
+ return fd;
+
+ /* Fall back to unguessable name + unlinking */
+ p = strjoina(directory, "/systemd-tmp-XXXXXX");
+
+ fd = mkostemp_safe(p);
+ if (fd < 0)
+ return fd;
+
+ (void) unlink(p);
+
+ return fd;
+}
+
+int open_tmpfile_linkable(const char *target, int flags, char **ret_path) {
+ _cleanup_free_ char *tmp = NULL;
+ int r, fd;
+
+ assert(target);
+ assert(ret_path);
+
+ /* Don't allow O_EXCL, as that has a special meaning for O_TMPFILE */
+ assert((flags & O_EXCL) == 0);
+
+ /* Creates a temporary file, that shall be renamed to "target" later. If possible, this uses O_TMPFILE – in
+ * which case "ret_path" will be returned as NULL. If not possible a the tempoary path name used is returned in
+ * "ret_path". Use link_tmpfile() below to rename the result after writing the file in full. */
+
+ {
+ _cleanup_free_ char *dn = NULL;
+
+ dn = dirname_malloc(target);
+ if (!dn)
+ return -ENOMEM;
+
+ fd = open(dn, O_TMPFILE|flags, 0640);
+ if (fd >= 0) {
+ *ret_path = NULL;
+ return fd;
+ }
+
+ log_debug_errno(errno, "Failed to use O_TMPFILE on %s: %m", dn);
+ }
+
+ r = tempfn_random(target, NULL, &tmp);
+ if (r < 0)
+ return r;
+
+ fd = open(tmp, O_CREAT|O_EXCL|O_NOFOLLOW|O_NOCTTY|flags, 0640);
+ if (fd < 0)
+ return -errno;
+
+ *ret_path = tmp;
+ tmp = NULL;
+
+ return fd;
+}
+
+int link_tmpfile(int fd, const char *path, const char *target) {
+
+ assert(fd >= 0);
+ assert(target);
+
+ /* Moves a temporary file created with open_tmpfile() above into its final place. if "path" is NULL an fd
+ * created with O_TMPFILE is assumed, and linkat() is used. Otherwise it is assumed O_TMPFILE is not supported
+ * on the directory, and renameat2() is used instead.
+ *
+ * Note that in both cases we will not replace existing files. This is because linkat() does not support this
+ * operation currently (renameat2() does), and there is no nice way to emulate this. */
+
+ if (path) {
+ if (rename_noreplace(AT_FDCWD, path, AT_FDCWD, target) < 0)
+ return -errno;
+ } else {
+ char proc_fd_path[strlen("/proc/self/fd/") + DECIMAL_STR_MAX(fd) + 1];
+
+ xsprintf(proc_fd_path, "/proc/self/fd/%i", fd);
+
+ if (linkat(AT_FDCWD, proc_fd_path, AT_FDCWD, target, AT_SYMLINK_FOLLOW) < 0)
+ return -errno;
+ }
+
+ return 0;
+}
+
+int read_nul_string(FILE *f, char **ret) {
+ _cleanup_free_ char *x = NULL;
+ size_t allocated = 0, n = 0;
+
+ assert(f);
+ assert(ret);
+
+ /* Reads a NUL-terminated string from the specified file. */
+
+ for (;;) {
+ int c;
+
+ if (!GREEDY_REALLOC(x, allocated, n+2))
+ return -ENOMEM;
+
+ c = fgetc(f);
+ if (c == 0) /* Terminate at NUL byte */
+ break;
+ if (c == EOF) {
+ if (ferror(f))
+ return -errno;
+ break; /* Terminate at EOF */
+ }
+
+ x[n++] = (char) c;
+ }
+
+ if (x)
+ x[n] = 0;
+ else {
+ x = new0(char, 1);
+ if (!x)
+ return -ENOMEM;
+ }
+
+ *ret = x;
+ x = NULL;
+
return 0;
}