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path: root/src/systemd/src/basic/fileio.c
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Diffstat (limited to 'src/systemd/src/basic/fileio.c')
-rw-r--r--src/systemd/src/basic/fileio.c160
1 files changed, 117 insertions, 43 deletions
diff --git a/src/systemd/src/basic/fileio.c b/src/systemd/src/basic/fileio.c
index 6220d1c11d..9ee7a4af38 100644
--- a/src/systemd/src/basic/fileio.c
+++ b/src/systemd/src/basic/fileio.c
@@ -30,6 +30,7 @@
#include "alloc-util.h"
#include "ctype.h"
+#include "def.h"
#include "env-util.h"
#include "escape.h"
#include "fd-util.h"
@@ -52,13 +53,17 @@
#define READ_FULL_BYTES_MAX (4U*1024U*1024U)
-int write_string_stream_ts(FILE *f, const char *line, bool enforce_newline, struct timespec *ts) {
+int write_string_stream_ts(
+ FILE *f,
+ const char *line,
+ WriteStringFileFlags flags,
+ struct timespec *ts) {
assert(f);
assert(line);
fputs(line, f);
- if (enforce_newline && !endswith(line, "\n"))
+ if (!(flags & WRITE_STRING_FILE_AVOID_NEWLINE) && !endswith(line, "\n"))
fputc('\n', f);
if (ts) {
@@ -68,10 +73,18 @@ int write_string_stream_ts(FILE *f, const char *line, bool enforce_newline, stru
return -errno;
}
- return fflush_and_check(f);
+ if (flags & WRITE_STRING_FILE_SYNC)
+ return fflush_sync_and_check(f);
+ else
+ return fflush_and_check(f);
}
-static int write_string_file_atomic(const char *fn, const char *line, bool enforce_newline, bool do_fsync) {
+static int write_string_file_atomic(
+ const char *fn,
+ const char *line,
+ WriteStringFileFlags flags,
+ struct timespec *ts) {
+
_cleanup_fclose_ FILE *f = NULL;
_cleanup_free_ char *p = NULL;
int r;
@@ -85,22 +98,28 @@ static int write_string_file_atomic(const char *fn, const char *line, bool enfor
(void) fchmod_umask(fileno(f), 0644);
- r = write_string_stream(f, line, enforce_newline);
- if (r >= 0 && do_fsync)
- r = fflush_sync_and_check(f);
+ r = write_string_stream_ts(f, line, flags, ts);
+ if (r < 0)
+ goto fail;
- if (r >= 0) {
- if (rename(p, fn) < 0)
- r = -errno;
+ if (rename(p, fn) < 0) {
+ r = -errno;
+ goto fail;
}
- if (r < 0)
- (void) unlink(p);
+ return 0;
+fail:
+ (void) unlink(p);
return r;
}
-int write_string_file_ts(const char *fn, const char *line, WriteStringFileFlags flags, struct timespec *ts) {
+int write_string_file_ts(
+ const char *fn,
+ const char *line,
+ WriteStringFileFlags flags,
+ struct timespec *ts) {
+
_cleanup_fclose_ FILE *f = NULL;
int q, r;
@@ -113,8 +132,7 @@ int write_string_file_ts(const char *fn, const char *line, WriteStringFileFlags
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),
- flags & WRITE_STRING_FILE_SYNC);
+ r = write_string_file_atomic(fn, line, flags, ts);
if (r < 0)
goto fail;
@@ -147,16 +165,10 @@ int write_string_file_ts(const char *fn, const char *line, WriteStringFileFlags
}
}
- r = write_string_stream_ts(f, line, !(flags & WRITE_STRING_FILE_AVOID_NEWLINE), ts);
+ r = write_string_stream_ts(f, line, flags, ts);
if (r < 0)
goto fail;
- if (flags & WRITE_STRING_FILE_SYNC) {
- r = fflush_sync_and_check(f);
- if (r < 0)
- return r;
- }
-
return 0;
fail:
@@ -177,7 +189,7 @@ fail:
int read_one_line_file(const char *fn, char **line) {
_cleanup_fclose_ FILE *f = NULL;
- char t[LINE_MAX], *c;
+ int r;
assert(fn);
assert(line);
@@ -186,21 +198,8 @@ int read_one_line_file(const char *fn, char **line) {
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;
+ r = read_line(f, LONG_LINE_MAX, line);
+ return r < 0 ? r : 0;
}
int verify_file(const char *fn, const char *blob, bool accept_extra_nl) {
@@ -259,11 +258,11 @@ int read_full_stream(FILE *f, char **contents, size_t *size) {
if (st.st_size > READ_FULL_BYTES_MAX)
return -E2BIG;
- /* Start with the right file size, but be prepared for
- * files from /proc which generally report a file size
- * of 0 */
+ /* Start with the right file size, but be prepared for files from /proc which generally report a file
+ * size of 0. Note that we increase the size to read here by one, so that the first read attempt
+ * already makes us notice the EOF. */
if (st.st_size > 0)
- n = st.st_size;
+ n = st.st_size + 1;
}
l = 0;
@@ -276,12 +275,13 @@ int read_full_stream(FILE *f, char **contents, size_t *size) {
return -ENOMEM;
buf = t;
+ errno = 0;
k = fread(buf + l, 1, n - l, f);
if (k > 0)
l += k;
if (ferror(f))
- return -errno;
+ return errno > 0 ? -errno : -EIO;
if (feof(f))
break;
@@ -1526,3 +1526,77 @@ int mkdtemp_malloc(const char *template, char **ret) {
*ret = p;
return 0;
}
+
+static inline void funlockfilep(FILE **f) {
+ funlockfile(*f);
+}
+
+int read_line(FILE *f, size_t limit, char **ret) {
+ _cleanup_free_ char *buffer = NULL;
+ size_t n = 0, allocated = 0, count = 0;
+
+ assert(f);
+
+ /* Something like a bounded version of getline().
+ *
+ * Considers EOF, \n and \0 end of line delimiters, and does not include these delimiters in the string
+ * returned.
+ *
+ * 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, allocated, 1))
+ return -ENOMEM;
+ }
+
+ {
+ _cleanup_(funlockfilep) FILE *flocked = f;
+ flockfile(f);
+
+ for (;;) {
+ int c;
+
+ if (n >= limit)
+ return -ENOBUFS;
+
+ errno = 0;
+ c = fgetc_unlocked(f);
+ if (c == EOF) {
+ /* if we read an error, and have no data to return, then propagate the error */
+ if (ferror_unlocked(f) && n == 0)
+ return errno > 0 ? -errno : -EIO;
+
+ break;
+ }
+
+ count++;
+
+ if (IN_SET(c, '\n', 0)) /* Reached a delimiter */
+ break;
+
+ if (ret) {
+ if (!GREEDY_REALLOC(buffer, allocated, n + 2))
+ return -ENOMEM;
+
+ buffer[n] = (char) c;
+ }
+
+ n++;
+ }
+ }
+
+ if (ret) {
+ buffer[n] = 0;
+
+ *ret = buffer;
+ buffer = NULL;
+ }
+
+ return (int) count;
+}
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