blob: f183de49992d462ccababcef52b8ac490aa7a15d [file] [log] [blame] [raw]
/***
This file is part of systemd.
Copyright 2010 Lennart Poettering
systemd is free software; you can redistribute it and/or modify it
under the terms of the GNU Lesser General Public License as published by
the Free Software Foundation; either version 2.1 of the License, or
(at your option) any later version.
systemd is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public License
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 "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 "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"
int write_string_stream(FILE *f, const char *line, bool enforce_newline) {
assert(f);
assert(line);
fputs(line, f);
if (enforce_newline && !endswith(line, "\n"))
fputc('\n', f);
return fflush_and_check(f);
}
static int write_string_file_atomic(const char *fn, const char *line, bool enforce_newline) {
_cleanup_fclose_ FILE *f = NULL;
_cleanup_free_ char *p = NULL;
int r;
assert(fn);
assert(line);
r = fopen_temporary(fn, &f, &p);
if (r < 0)
return r;
(void) fchmod_umask(fileno(f), 0644);
r = write_string_stream(f, line, enforce_newline);
if (r >= 0) {
if (rename(p, fn) < 0)
r = -errno;
}
if (r < 0)
(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);
if (flags & WRITE_STRING_FILE_ATOMIC) {
assert(flags & WRITE_STRING_FILE_CREATE);
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) {
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) {
r = -errno;
goto fail;
}
f = fdopen(fd, "we");
if (!f) {
r = -errno;
safe_close(fd);
goto fail;
}
}
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) {
_cleanup_fclose_ FILE *f = NULL;
char t[LINE_MAX], *c;
assert(fn);
assert(line);
f = fopen(fn, "re");
if (!f)
return -errno;
if (!fgets(t, sizeof(t), f)) {
if (ferror(f))
return errno > 0 ? -errno : -EIO;
t[0] = 0;
}
c = strdup(t);
if (!c)
return -ENOMEM;
truncate_nl(c);
*line = c;
return 0;
}
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;
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;
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) {
size_t n, l;
_cleanup_free_ char *buf = NULL;
struct stat st;
assert(f);
assert(contents);
if (fstat(fileno(f), &st) < 0)
return -errno;
n = LINE_MAX;
if (S_ISREG(st.st_mode)) {
/* Safety check */
if (st.st_size > 4*1024*1024)
return -E2BIG;
/* Start with the right file size, but be prepared for
* files from /proc which generally report a file size
* of 0 */
if (st.st_size > 0)
n = st.st_size;
}
l = 0;
for (;;) {
char *t;
size_t k;
t = realloc(buf, n+1);
if (!t)
return -ENOMEM;
buf = t;
k = fread(buf + l, 1, n - l, f);
if (k <= 0) {
if (ferror(f))
return -errno;
break;
}
l += k;
n *= 2;
/* Safety check */
if (n > 4*1024*1024)
return -E2BIG;
}
buf[l] = 0;
*contents = buf;
buf = NULL; /* do not free */
if (size)
*size = l;
return 0;
}
int read_full_file(const char *fn, char **contents, size_t *size) {
_cleanup_fclose_ FILE *f = NULL;
assert(fn);
assert(contents);
f = fopen(fn, "re");
if (!f)
return -errno;
return read_full_stream(f, contents, size);
}
static int parse_env_file_internal(
FILE *f,
const char *fname,
const char *newline,
int (*push) (const char *filename, unsigned line,
const char *key, char *value, void *userdata, int *n_pushed),
void *userdata,
int *n_pushed) {
_cleanup_free_ char *contents = NULL, *key = NULL;
size_t key_alloc = 0, n_key = 0, value_alloc = 0, n_value = 0, last_value_whitespace = (size_t) -1, last_key_whitespace = (size_t) -1;
char *p, *value = NULL;
int r;
unsigned line = 1;
enum {
PRE_KEY,
KEY,
PRE_VALUE,
VALUE,
VALUE_ESCAPE,
SINGLE_QUOTE_VALUE,
SINGLE_QUOTE_VALUE_ESCAPE,
DOUBLE_QUOTE_VALUE,
DOUBLE_QUOTE_VALUE_ESCAPE,
COMMENT,
COMMENT_ESCAPE
} state = PRE_KEY;
assert(newline);
if (f)
r = read_full_stream(f, &contents, NULL);
else
r = read_full_file(fname, &contents, NULL);
if (r < 0)
return r;
for (p = contents; *p; p++) {
char c = *p;
switch (state) {
case PRE_KEY:
if (strchr(COMMENTS, c))
state = COMMENT;
else if (!strchr(WHITESPACE, c)) {
state = KEY;
last_key_whitespace = (size_t) -1;
if (!GREEDY_REALLOC(key, key_alloc, n_key+2)) {
r = -ENOMEM;
goto fail;
}
key[n_key++] = c;
}
break;
case KEY:
if (strchr(newline, c)) {
state = PRE_KEY;
line++;
n_key = 0;
} else if (c == '=') {
state = PRE_VALUE;
last_value_whitespace = (size_t) -1;
} else {
if (!strchr(WHITESPACE, c))
last_key_whitespace = (size_t) -1;
else if (last_key_whitespace == (size_t) -1)
last_key_whitespace = n_key;
if (!GREEDY_REALLOC(key, key_alloc, n_key+2)) {
r = -ENOMEM;
goto fail;
}
key[n_key++] = c;
}
break;
case PRE_VALUE:
if (strchr(newline, c)) {
state = PRE_KEY;
line++;
key[n_key] = 0;
if (value)
value[n_value] = 0;
/* strip trailing whitespace from key */
if (last_key_whitespace != (size_t) -1)
key[last_key_whitespace] = 0;
r = push(fname, line, key, value, userdata, n_pushed);
if (r < 0)
goto fail;
n_key = 0;
value = NULL;
value_alloc = n_value = 0;
} else if (c == '\'')
state = SINGLE_QUOTE_VALUE;
else if (c == '\"')
state = DOUBLE_QUOTE_VALUE;
else if (c == '\\')
state = VALUE_ESCAPE;
else if (!strchr(WHITESPACE, c)) {
state = VALUE;
if (!GREEDY_REALLOC(value, value_alloc, n_value+2)) {
r = -ENOMEM;
goto fail;
}
value[n_value++] = c;
}
break;
case VALUE:
if (strchr(newline, c)) {
state = PRE_KEY;
line++;
key[n_key] = 0;
if (value)
value[n_value] = 0;
/* Chomp off trailing whitespace from value */
if (last_value_whitespace != (size_t) -1)
value[last_value_whitespace] = 0;
/* strip trailing whitespace from key */
if (last_key_whitespace != (size_t) -1)
key[last_key_whitespace] = 0;
r = push(fname, line, key, value, userdata, n_pushed);
if (r < 0)
goto fail;
n_key = 0;
value = NULL;
value_alloc = n_value = 0;
} else if (c == '\\') {
state = VALUE_ESCAPE;
last_value_whitespace = (size_t) -1;
} else {
if (!strchr(WHITESPACE, c))
last_value_whitespace = (size_t) -1;
else if (last_value_whitespace == (size_t) -1)
last_value_whitespace = n_value;
if (!GREEDY_REALLOC(value, value_alloc, n_value+2)) {
r = -ENOMEM;
goto fail;
}
value[n_value++] = c;
}
break;
case VALUE_ESCAPE:
state = VALUE;
if (!strchr(newline, c)) {
/* Escaped newlines we eat up entirely */
if (!GREEDY_REALLOC(value, value_alloc, n_value+2)) {
r = -ENOMEM;
goto fail;
}
value[n_value++] = c;
}
break;
case SINGLE_QUOTE_VALUE:
if (c == '\'')
state = PRE_VALUE;
else if (c == '\\')
state = SINGLE_QUOTE_VALUE_ESCAPE;
else {
if (!GREEDY_REALLOC(value, value_alloc, n_value+2)) {
r = -ENOMEM;
goto fail;
}
value[n_value++] = c;
}
break;
case SINGLE_QUOTE_VALUE_ESCAPE:
state = SINGLE_QUOTE_VALUE;
if (!strchr(newline, c)) {
if (!GREEDY_REALLOC(value, value_alloc, n_value+2)) {
r = -ENOMEM;
goto fail;
}
value[n_value++] = c;
}
break;
case DOUBLE_QUOTE_VALUE:
if (c == '\"')
state = PRE_VALUE;
else if (c == '\\')
state = DOUBLE_QUOTE_VALUE_ESCAPE;
else {
if (!GREEDY_REALLOC(value, value_alloc, n_value+2)) {
r = -ENOMEM;
goto fail;
}
value[n_value++] = c;
}
break;
case DOUBLE_QUOTE_VALUE_ESCAPE:
state = DOUBLE_QUOTE_VALUE;
if (!strchr(newline, c)) {
if (!GREEDY_REALLOC(value, value_alloc, n_value+2)) {
r = -ENOMEM;
goto fail;
}
value[n_value++] = c;
}
break;
case COMMENT:
if (c == '\\')
state = COMMENT_ESCAPE;
else if (strchr(newline, c)) {
state = PRE_KEY;
line++;
}
break;
case COMMENT_ESCAPE:
state = COMMENT;
break;
}
}
if (state == PRE_VALUE ||
state == VALUE ||
state == VALUE_ESCAPE ||
state == SINGLE_QUOTE_VALUE ||
state == SINGLE_QUOTE_VALUE_ESCAPE ||
state == DOUBLE_QUOTE_VALUE ||
state == DOUBLE_QUOTE_VALUE_ESCAPE) {
key[n_key] = 0;
if (value)
value[n_value] = 0;
if (state == VALUE)
if (last_value_whitespace != (size_t) -1)
value[last_value_whitespace] = 0;
/* strip trailing whitespace from key */
if (last_key_whitespace != (size_t) -1)
key[last_key_whitespace] = 0;
r = push(fname, line, key, value, userdata, n_pushed);
if (r < 0)
goto fail;
}
return 0;
fail:
free(value);
return r;
}
static int parse_env_file_push(
const char *filename, unsigned line,
const char *key, char *value,
void *userdata,
int *n_pushed) {
const char *k;
va_list aq, *ap = userdata;
if (!utf8_is_valid(key)) {
_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);
return -EINVAL;
}
if (value && !utf8_is_valid(value)) {
_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);
return -EINVAL;
}
va_copy(aq, *ap);
while ((k = va_arg(aq, const char *))) {
char **v;
v = va_arg(aq, char **);
if (streq(key, k)) {
va_end(aq);
free(*v);
*v = value;
if (n_pushed)
(*n_pushed)++;
return 1;
}
}
va_end(aq);
free(value);
return 0;
}
int parse_env_file(
const char *fname,
const char *newline, ...) {
va_list ap;
int r, n_pushed = 0;
if (!newline)
newline = NEWLINE;
va_start(ap, newline);
r = parse_env_file_internal(NULL, fname, newline, parse_env_file_push, &ap, &n_pushed);
va_end(ap);
return r < 0 ? r : n_pushed;
}
static int load_env_file_push(
const char *filename, unsigned line,
const char *key, char *value,
void *userdata,
int *n_pushed) {
char ***m = userdata;
char *p;
int r;
if (!utf8_is_valid(key)) {
_cleanup_free_ char *t = utf8_escape_invalid(key);
log_error("%s:%u: invalid UTF-8 for key '%s', ignoring.", strna(filename), line, t);
return -EINVAL;
}
if (value && !utf8_is_valid(value)) {
_cleanup_free_ char *t = utf8_escape_invalid(value);
log_error("%s:%u: invalid UTF-8 value for key %s: '%s', ignoring.", strna(filename), line, key, t);
return -EINVAL;
}
p = strjoin(key, "=", strempty(value), NULL);
if (!p)
return -ENOMEM;
r = strv_consume(m, p);
if (r < 0)
return r;
if (n_pushed)
(*n_pushed)++;
free(value);
return 0;
}
int load_env_file(FILE *f, const char *fname, const char *newline, char ***rl) {
char **m = NULL;
int r;
if (!newline)
newline = NEWLINE;
r = parse_env_file_internal(f, fname, newline, load_env_file_push, &m, NULL);
if (r < 0) {
strv_free(m);
return r;
}
*rl = m;
return 0;
}
static int load_env_file_push_pairs(
const char *filename, unsigned line,
const char *key, char *value,
void *userdata,
int *n_pushed) {
char ***m = userdata;
int r;
if (!utf8_is_valid(key)) {
_cleanup_free_ char *t = utf8_escape_invalid(key);
log_error("%s:%u: invalid UTF-8 for key '%s', ignoring.", strna(filename), line, t);
return -EINVAL;
}
if (value && !utf8_is_valid(value)) {
_cleanup_free_ char *t = utf8_escape_invalid(value);
log_error("%s:%u: invalid UTF-8 value for key %s: '%s', ignoring.", strna(filename), line, key, t);
return -EINVAL;
}
r = strv_extend(m, key);
if (r < 0)
return -ENOMEM;
if (!value) {
r = strv_extend(m, "");
if (r < 0)
return -ENOMEM;
} else {
r = strv_push(m, value);
if (r < 0)
return r;
}
if (n_pushed)
(*n_pushed)++;
return 0;
}
int load_env_file_pairs(FILE *f, const char *fname, const char *newline, char ***rl) {
char **m = NULL;
int r;
if (!newline)
newline = NEWLINE;
r = parse_env_file_internal(f, fname, newline, load_env_file_push_pairs, &m, NULL);
if (r < 0) {
strv_free(m);
return r;
}
*rl = m;
return 0;
}
static void write_env_var(FILE *f, const char *v) {
const char *p;
p = strchr(v, '=');
if (!p) {
/* Fallback */
fputs(v, f);
fputc('\n', f);
return;
}
p++;
fwrite(v, 1, p-v, f);
if (string_has_cc(p, NULL) || chars_intersect(p, WHITESPACE SHELL_NEED_QUOTES)) {
fputc('\"', f);
for (; *p; p++) {
if (strchr(SHELL_NEED_ESCAPE, *p))
fputc('\\', f);
fputc(*p, f);
}
fputc('\"', f);
} else
fputs(p, f);
fputc('\n', f);
}
int write_env_file(const char *fname, char **l) {
_cleanup_fclose_ FILE *f = NULL;
_cleanup_free_ char *p = NULL;
char **i;
int r;
assert(fname);
r = fopen_temporary(fname, &f, &p);
if (r < 0)
return r;
fchmod_umask(fileno(f), 0644);
STRV_FOREACH(i, l)
write_env_var(f, *i);
r = fflush_and_check(f);
if (r >= 0) {
if (rename(p, fname) >= 0)
return 0;
r = -errno;
}
unlink(p);
return r;
}
int executable_is_script(const char *path, char **interpreter) {
int r;
_cleanup_free_ char *line = NULL;
int len;
char *ans;
assert(path);
r = read_one_line_file(path, &line);
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;
size_t len;
int r;
assert(terminator);
assert(filename);
assert(pattern);
assert(field);
r = read_full_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--;
}
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;
}
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 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 > 0 ? -errno : -EIO;
return 0;
}
/* This is much like mkostemp() but is subject to umask(). */
int mkostemp_safe(char *pattern, int flags) {
_cleanup_umask_ mode_t u = 0;
int fd;
assert(pattern);
u = umask(077);
fd = mkostemp(pattern, flags);
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;
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;
}
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;
if (!directory)
directory = "/tmp";
/* Returns an unlinked temporary file that cannot be linked into the file system anymore */
#ifdef O_TMPFILE
/* 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;
#endif
/* Fall back to unguessable name + unlinking */
p = strjoina(directory, "/systemd-tmp-XXXXXX");
fd = mkostemp_safe(p, flags);
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. */
#ifdef O_TMPFILE
{
_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);
}
#endif
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;
}