fileio.c revision e93c33d4aadb41427f215d43545e7fadc6bcec6f
/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
/***
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 <unistd.h>
#include <sys/sendfile.h>
#include "fileio.h"
#include "util.h"
#include "strv.h"
#include "utf8.h"
#include "ctype.h"
int write_string_to_file(FILE *f, const char *line) {
errno = 0;
fputs(line, f);
if (!endswith(line, "\n"))
fputc('\n', f);
fflush(f);
if (ferror(f))
return errno ? -errno : -EIO;
return 0;
}
int write_string_file(const char *fn, const char *line) {
_cleanup_fclose_ FILE *f = NULL;
assert(fn);
assert(line);
f = fopen(fn, "we");
if (!f)
return -errno;
return write_string_to_file(f, line);
}
int write_string_file_atomic(const char *fn, const char *line) {
_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;
fchmod_umask(fileno(f), 0644);
errno = 0;
fputs(line, f);
if (!endswith(line, "\n"))
fputc('\n', f);
fflush(f);
if (ferror(f))
r = errno ? -errno : -EIO;
else {
if (rename(p, fn) < 0)
r = -errno;
else
r = 0;
}
if (r < 0)
unlink(p);
return r;
}
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 ? -errno : -EIO;
t[0] = 0;
}
c = strdup(t);
if (!c)
return -ENOMEM;
truncate_nl(c);
*line = c;
return 0;
}
ssize_t sendfile_full(int out_fd, const char *fn) {
_cleanup_fclose_ FILE *f;
struct stat st;
int r;
ssize_t s;
size_t n, l;
_cleanup_free_ char *buf = NULL;
assert(out_fd > 0);
assert(fn);
f = fopen(fn, "r");
if (!f)
return -errno;
r = fstat(fileno(f), &st);
if (r < 0)
return -errno;
s = sendfile(out_fd, fileno(f), NULL, st.st_size);
if (s < 0)
if (errno == EINVAL || errno == ENOSYS) {
/* continue below */
} else
return -errno;
else
return s;
/* sendfile() failed, fall back to read/write */
/* Safety check */
if (st.st_size > 4*1024*1024)
return -E2BIG;
n = st.st_size > 0 ? st.st_size : LINE_MAX;
l = 0;
while (true) {
char *t;
size_t k;
t = realloc(buf, n);
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;
}
r = write(out_fd, buf, l);
if (r < 0)
return -errno;
return (ssize_t) l;
}
int read_full_file(const char *fn, char **contents, size_t *size) {
_cleanup_fclose_ FILE *f = NULL;
size_t n, l;
_cleanup_free_ char *buf = NULL;
struct stat st;
assert(fn);
assert(contents);
f = fopen(fn, "re");
if (!f)
return -errno;
if (fstat(fileno(f), &st) < 0)
return -errno;
/* Safety check */
if (st.st_size > 4*1024*1024)
return -E2BIG;
n = st.st_size > 0 ? st.st_size : LINE_MAX;
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;
if (size)
*size = l;
return 0;
}
static int parse_env_file_internal(
const char *fname,
const char *newline,
int (*push) (const char *filename, unsigned line,
const char *key, char *value, void *userdata),
void *userdata) {
_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(fname);
assert(newline);
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((void**) &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((void**) &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);
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((void**) &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);
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((void**) &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((void**) &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((void**) &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((void**) &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((void**) &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((void**) &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);
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) {
assert(utf8_is_valid(key));
if (value && !utf8_is_valid(value))
/* FIXME: filter UTF-8 */
log_error("%s:%u: invalid UTF-8 for key %s: '%s', ignoring.",
filename, line, key, value);
else {
const char *k;
va_list* ap = (va_list*) userdata;
va_list aq;
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;
return 1;
}
}
va_end(aq);
}
free(value);
return 0;
}
int parse_env_file(
const char *fname,
const char *newline, ...) {
va_list ap;
int r;
if (!newline)
newline = NEWLINE;
va_start(ap, newline);
r = parse_env_file_internal(fname, newline, parse_env_file_push, &ap);
va_end(ap);
return r;
}
static int load_env_file_push(const char *filename, unsigned line,
const char *key, char *value, void *userdata) {
assert(utf8_is_valid(key));
if (value && !utf8_is_valid(value))
/* FIXME: filter UTF-8 */
log_error("%s:%u: invalid UTF-8 for key %s: '%s', ignoring.",
filename, line, key, value);
else {
char ***m = userdata;
char *p;
int r;
p = strjoin(key, "=", strempty(value), NULL);
if (!p)
return -ENOMEM;
r = strv_push(m, p);
if (r < 0) {
free(p);
return r;
}
}
free(value);
return 0;
}
int load_env_file(const char *fname, const char *newline, char ***rl) {
char **m = NULL;
int r;
if (!newline)
newline = NEWLINE;
r = parse_env_file_internal(fname, newline, load_env_file_push, &m);
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) || chars_intersect(p, WHITESPACE "\'\"\\`$")) {
fputc('\"', f);
for (; *p; p++) {
if (strchr("\'\"\\`$", *p))
fputc('\\', f);
fputc(*p, f);
}
fputc('\"', f);
} else
fputs(p, f);
fputc('\n', f);
}
int write_env_file(const char *fname, char **l) {
char **i;
_cleanup_free_ char *p = NULL;
_cleanup_fclose_ FILE *f = NULL;
int r;
r = fopen_temporary(fname, &f, &p);
if (r < 0)
return r;
fchmod_umask(fileno(f), 0644);
errno = 0;
STRV_FOREACH(i, l)
write_env_var(f, *i);
fflush(f);
if (ferror(f))
r = errno ? -errno : -EIO;
else {
if (rename(p, fname) < 0)
r = -errno;
else
r = 0;
}
if (r < 0)
unlink(p);
return r;
}
int executable_is_script(const char *path, char **interpreter) {
int r;
char _cleanup_free_ *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 start with '\n' and end with a ':'. Whitespace and zeros
* after the ':' will be skipped. field must be freed afterwards.
*/
int get_status_field(const char *filename, const char *pattern, char **field) {
_cleanup_free_ char *status = NULL;
char *t;
size_t len;
int r;
assert(filename);
assert(pattern);
assert(field);
r = read_full_file(filename, &status, NULL);
if (r < 0)
return r;
t = strstr(status, pattern);
if (!t)
return -ENOENT;
t += strlen(pattern);
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, WHITESPACE);
*field = strndup(t, len);
if (!*field)
return -ENOMEM;
return 0;
}