chiark / gitweb /
Prep v239: Add missing updates that evaded migration.
[elogind.git] / src / basic / fileio.c
index f666380a414e8f5554c9f2511d932aca3c5519bd..1cee6d49594e7f5f88730eba9234cfcb77040de8 100644 (file)
@@ -1,45 +1,98 @@
-/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
+/* SPDX-License-Identifier: LGPL-2.1+ */
+
+#include <errno.h>
+#include <fcntl.h>
+#include <limits.h>
+#include <stdarg.h>
+#include <stdint.h>
+#include <stdio_ext.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/mman.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <unistd.h>
 
-/***
-  This file is part of systemd.
+#include "alloc-util.h"
+#include "ctype.h"
+#include "def.h"
+#include "env-util.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 "process-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"
 
-  Copyright 2010 Lennart Poettering
+#define READ_FULL_BYTES_MAX (4U*1024U*1024U)
 
-  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.
+int write_string_stream_ts(
+                FILE *f,
+                const char *line,
+                WriteStringFileFlags flags,
+                struct timespec *ts) {
 
-  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.
+        bool needs_nl;
+        int r;
 
-  You should have received a copy of the GNU Lesser General Public License
-  along with systemd; If not, see <http://www.gnu.org/licenses/>.
-***/
+        assert(f);
+        assert(line);
 
-#include <unistd.h>
+        if (ferror(f))
+                return -EIO;
 
-#include "util.h"
-#include "strv.h"
-#include "utf8.h"
-#include "ctype.h"
-#include "fileio.h"
+        needs_nl = !(flags & WRITE_STRING_FILE_AVOID_NEWLINE) && !endswith(line, "\n");
 
-int write_string_stream(FILE *f, const char *line, bool enforce_newline) {
+        if (needs_nl && (flags & WRITE_STRING_FILE_DISABLE_BUFFER)) {
+                /* If STDIO buffering was disabled, then let's append the newline character to the string itself, so
+                 * that the write goes out in one go, instead of two */
 
-        assert(f);
-        assert(line);
+                line = strjoina(line, "\n");
+                needs_nl = false;
+        }
+
+        if (fputs(line, f) == EOF)
+                return -errno;
+
+        if (needs_nl)
+                if (fputc('\n', f) == EOF)
+                        return -errno;
+
+        if (flags & WRITE_STRING_FILE_SYNC)
+                r = fflush_sync_and_check(f);
+        else
+                r = fflush_and_check(f);
+        if (r < 0)
+                return r;
+
+        if (ts) {
+                struct timespec twice[2] = {*ts, *ts};
 
-        fputs(line, f);
-        if (enforce_newline && !endswith(line, "\n"))
-                fputc('\n', f);
+                if (futimens(fileno(f), twice) < 0)
+                        return -errno;
+        }
 
-        return fflush_and_check(f);
+        return 0;
 }
 
-static int write_string_file_atomic(const char *fn, const char *line, bool enforce_newline) {
+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;
@@ -51,58 +104,125 @@ 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) __fsetlocking(f, FSETLOCKING_BYCALLER);
+        (void) fchmod_umask(fileno(f), 0644);
 
-        r = write_string_stream(f, line, enforce_newline);
-        if (r >= 0) {
-                if (rename(p, fn) < 0)
-                        r = -errno;
+        r = write_string_stream_ts(f, line, flags, ts);
+        if (r < 0)
+                goto fail;
+
+        if (rename(p, fn) < 0) {
+                r = -errno;
+                goto fail;
         }
 
-        if (r < 0)
-                unlink(p);
+        return 0;
 
+fail:
+        (void) unlink(p);
         return r;
 }
 
-int write_string_file(const char *fn, const char *line, WriteStringFileFlags flags) {
+int write_string_file_ts(
+                const char *fn,
+                const char *line,
+                WriteStringFileFlags flags,
+                struct timespec *ts) {
+
         _cleanup_fclose_ FILE *f = NULL;
+        int q, r;
 
         assert(fn);
         assert(line);
 
+        /* We don't know how to verify whether the file contents was already on-disk. */
+        assert(!((flags & WRITE_STRING_FILE_VERIFY_ON_FAILURE) && (flags & WRITE_STRING_FILE_SYNC)));
+
         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, ts);
+                if (r < 0)
+                        goto fail;
+
+                return r;
+        } else
+                assert(!ts);
 
         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));
+        (void) __fsetlocking(f, FSETLOCKING_BYCALLER);
+
+        if (flags & WRITE_STRING_FILE_DISABLE_BUFFER)
+                setvbuf(f, NULL, _IONBF, 0);
+
+        r = write_string_stream_ts(f, line, flags, ts);
+        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 write_string_filef(
+                const char *fn,
+                WriteStringFileFlags flags,
+                const char *format, ...) {
+
+        _cleanup_free_ char *p = NULL;
+        va_list ap;
+        int r;
+
+        va_start(ap, format);
+        r = vasprintf(&p, format, ap);
+        va_end(ap);
+
+        if (r < 0)
+                return -ENOMEM;
+
+        return write_string_file(fn, p, flags);
 }
 
 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);
@@ -111,61 +231,81 @@ int read_one_line_file(const char *fn, char **line) {
         if (!f)
                 return -errno;
 
-        if (!fgets(t, sizeof(t), f)) {
+        (void) __fsetlocking(f, FSETLOCKING_BYCALLER);
 
-                if (ferror(f))
-                        return errno ? -errno : -EIO;
+        r = read_line(f, LONG_LINE_MAX, line);
+        return r < 0 ? r : 0;
+}
 
-                t[0] = 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);
 
-        c = strdup(t);
-        if (!c)
+        if (accept_extra_nl && endswith(blob, "\n"))
+                accept_extra_nl = false;
+
+        buf = malloc(l + accept_extra_nl + 1);
+        if (!buf)
                 return -ENOMEM;
-        truncate_nl(c);
 
-        *line = c;
-        return 0;
-}
+        f = fopen(fn, "re");
+        if (!f)
+                return -errno;
 
-/// UNNEEDED by elogind
-#if 0
-int verify_one_line_file(const char *fn, const char *line) {
-        _cleanup_free_ char *value = NULL;
-        int r;
+        (void) __fsetlocking(f, FSETLOCKING_BYCALLER);
 
-        r = read_one_line_file(fn, &value);
-        if (r < 0)
-                return r;
+        /* 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 streq(value, line);
+        return 1;
 }
-#endif // 0
 
 int read_full_stream(FILE *f, char **contents, size_t *size) {
-        size_t n, l;
         _cleanup_free_ char *buf = NULL;
         struct stat st;
+        size_t n, l;
+        int fd;
 
         assert(f);
         assert(contents);
 
-        if (fstat(fileno(f), &st) < 0)
-                return -errno;
-
         n = LINE_MAX;
 
-        if (S_ISREG(st.st_mode)) {
+        fd = fileno(f);
+        if (fd >= 0) { /* If the FILE* object is backed by an fd (as opposed to memory or such, see fmemopen(), let's
+                        * optimize our buffering) */
 
-                /* Safety check */
-                if (st.st_size > 4*1024*1024)
-                        return -E2BIG;
+                if (fstat(fileno(f), &st) < 0)
+                        return -errno;
 
-                /* 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;
+                if (S_ISREG(st.st_mode)) {
+
+                        /* Safety check */
+                        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. 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 + 1;
+                }
         }
 
         l = 0;
@@ -173,31 +313,36 @@ 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;
+                errno = 0;
                 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 > 0 ? -errno : -EIO;
 
+                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;
-        *contents = buf;
-        buf = NULL; /* do not free */
+        *contents = TAKE_PTR(buf);
 
         if (size)
                 *size = l;
@@ -215,6 +360,8 @@ int read_full_file(const char *fn, char **contents, size_t *size) {
         if (!f)
                 return -errno;
 
+        (void) __fsetlocking(f, FSETLOCKING_BYCALLER);
+
         return read_full_stream(f, contents, size);
 }
 
@@ -227,11 +374,11 @@ static int parse_env_file_internal(
                 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;
+        _cleanup_free_ char *contents = NULL, *key = NULL, *value = NULL;
         unsigned line = 1;
+        char *p;
+        int r;
 
         enum {
                 PRE_KEY,
@@ -268,10 +415,8 @@ static int parse_env_file_internal(
                                 state = KEY;
                                 last_key_whitespace = (size_t) -1;
 
-                                if (!GREEDY_REALLOC(key, key_alloc, n_key+2)) {
-                                        r = -ENOMEM;
-                                        goto fail;
-                                }
+                                if (!GREEDY_REALLOC(key, key_alloc, n_key+2))
+                                        return -ENOMEM;
 
                                 key[n_key++] = c;
                         }
@@ -280,7 +425,7 @@ 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;
@@ -291,10 +436,8 @@ static int parse_env_file_internal(
                                 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;
-                                }
+                                if (!GREEDY_REALLOC(key, key_alloc, n_key+2))
+                                        return -ENOMEM;
 
                                 key[n_key++] = c;
                         }
@@ -304,7 +447,7 @@ static int parse_env_file_internal(
                 case PRE_VALUE:
                         if (strchr(newline, c)) {
                                 state = PRE_KEY;
-                                line ++;
+                                line++;
                                 key[n_key] = 0;
 
                                 if (value)
@@ -316,7 +459,7 @@ static int parse_env_file_internal(
 
                                 r = push(fname, line, key, value, userdata, n_pushed);
                                 if (r < 0)
-                                        goto fail;
+                                        return r;
 
                                 n_key = 0;
                                 value = NULL;
@@ -331,10 +474,8 @@ static int parse_env_file_internal(
                         else if (!strchr(WHITESPACE, c)) {
                                 state = VALUE;
 
-                                if (!GREEDY_REALLOC(value, value_alloc, n_value+2)) {
-                                        r = -ENOMEM;
-                                        goto fail;
-                                }
+                                if (!GREEDY_REALLOC(value, value_alloc, n_value+2))
+                                        return  -ENOMEM;
 
                                 value[n_value++] = c;
                         }
@@ -344,7 +485,7 @@ static int parse_env_file_internal(
                 case VALUE:
                         if (strchr(newline, c)) {
                                 state = PRE_KEY;
-                                line ++;
+                                line++;
 
                                 key[n_key] = 0;
 
@@ -361,7 +502,7 @@ static int parse_env_file_internal(
 
                                 r = push(fname, line, key, value, userdata, n_pushed);
                                 if (r < 0)
-                                        goto fail;
+                                        return r;
 
                                 n_key = 0;
                                 value = NULL;
@@ -376,10 +517,8 @@ static int parse_env_file_internal(
                                 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;
-                                }
+                                if (!GREEDY_REALLOC(value, value_alloc, n_value+2))
+                                        return -ENOMEM;
 
                                 value[n_value++] = c;
                         }
@@ -391,10 +530,8 @@ static int parse_env_file_internal(
 
                         if (!strchr(newline, c)) {
                                 /* Escaped newlines we eat up entirely */
-                                if (!GREEDY_REALLOC(value, value_alloc, n_value+2)) {
-                                        r = -ENOMEM;
-                                        goto fail;
-                                }
+                                if (!GREEDY_REALLOC(value, value_alloc, n_value+2))
+                                        return -ENOMEM;
 
                                 value[n_value++] = c;
                         }
@@ -406,10 +543,8 @@ static int parse_env_file_internal(
                         else if (c == '\\')
                                 state = SINGLE_QUOTE_VALUE_ESCAPE;
                         else {
-                                if (!GREEDY_REALLOC(value, value_alloc, n_value+2)) {
-                                        r = -ENOMEM;
-                                        goto fail;
-                                }
+                                if (!GREEDY_REALLOC(value, value_alloc, n_value+2))
+                                        return -ENOMEM;
 
                                 value[n_value++] = c;
                         }
@@ -420,10 +555,8 @@ static int parse_env_file_internal(
                         state = SINGLE_QUOTE_VALUE;
 
                         if (!strchr(newline, c)) {
-                                if (!GREEDY_REALLOC(value, value_alloc, n_value+2)) {
-                                        r = -ENOMEM;
-                                        goto fail;
-                                }
+                                if (!GREEDY_REALLOC(value, value_alloc, n_value+2))
+                                        return -ENOMEM;
 
                                 value[n_value++] = c;
                         }
@@ -435,10 +568,8 @@ static int parse_env_file_internal(
                         else if (c == '\\')
                                 state = DOUBLE_QUOTE_VALUE_ESCAPE;
                         else {
-                                if (!GREEDY_REALLOC(value, value_alloc, n_value+2)) {
-                                        r = -ENOMEM;
-                                        goto fail;
-                                }
+                                if (!GREEDY_REALLOC(value, value_alloc, n_value+2))
+                                        return -ENOMEM;
 
                                 value[n_value++] = c;
                         }
@@ -449,10 +580,8 @@ static int parse_env_file_internal(
                         state = DOUBLE_QUOTE_VALUE;
 
                         if (!strchr(newline, c)) {
-                                if (!GREEDY_REALLOC(value, value_alloc, n_value+2)) {
-                                        r = -ENOMEM;
-                                        goto fail;
-                                }
+                                if (!GREEDY_REALLOC(value, value_alloc, n_value+2))
+                                        return -ENOMEM;
 
                                 value[n_value++] = c;
                         }
@@ -463,7 +592,7 @@ static int parse_env_file_internal(
                                 state = COMMENT_ESCAPE;
                         else if (strchr(newline, c)) {
                                 state = PRE_KEY;
-                                line ++;
+                                line++;
                         }
                         break;
 
@@ -473,13 +602,14 @@ static int parse_env_file_internal(
                 }
         }
 
-        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) {
+        if (IN_SET(state,
+                   PRE_VALUE,
+                   VALUE,
+                   VALUE_ESCAPE,
+                   SINGLE_QUOTE_VALUE,
+                   SINGLE_QUOTE_VALUE_ESCAPE,
+                   DOUBLE_QUOTE_VALUE,
+                   DOUBLE_QUOTE_VALUE_ESCAPE)) {
 
                 key[n_key] = 0;
 
@@ -496,27 +626,20 @@ static int parse_env_file_internal(
 
                 r = push(fname, line, key, value, userdata, n_pushed);
                 if (r < 0)
-                        goto fail;
+                        return r;
+
+                value = NULL;
         }
 
         return 0;
-
-fail:
-        free(value);
-        return r;
 }
 
-static int parse_env_file_push(
+static int check_utf8ness_and_warn(
                 const char *filename, unsigned line,
-                const char *key, char *value,
-                void *userdata,
-                int *n_pushed) {
-
-        const char *k;
-        va_list aq, *ap = userdata;
+                const char *key, char *value) {
 
         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);
@@ -524,13 +647,30 @@ 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);
                 return -EINVAL;
         }
 
+        return 0;
+}
+
+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;
+        int r;
+
+        r = check_utf8ness_and_warn(filename, line, key, value);
+        if (r < 0)
+                return r;
+
         va_copy(aq, *ap);
 
         while ((k = va_arg(aq, const char *))) {
@@ -556,23 +696,44 @@ static int parse_env_file_push(
         return 0;
 }
 
-int parse_env_file(
+int parse_env_filev(
+                FILE *f,
                 const char *fname,
-                const char *newline, ...) {
+                const char *newline,
+                va_list ap) {
 
-        va_list ap;
         int r, n_pushed = 0;
+        va_list aq;
 
         if (!newline)
                 newline = NEWLINE;
 
+        va_copy(aq, ap);
+        r = parse_env_file_internal(f, fname, newline, parse_env_file_push, &aq, &n_pushed);
+        va_end(aq);
+        if (r < 0)
+                return r;
+
+        return n_pushed;
+}
+
+int parse_env_file(
+                FILE *f,
+                const char *fname,
+                const char *newline,
+                ...) {
+
+        va_list ap;
+        int r;
+
         va_start(ap, newline);
-        r = parse_env_file_internal(NULL, fname, newline, parse_env_file_push, &ap, &n_pushed);
+        r = parse_env_filev(f, fname, newline, ap);
         va_end(ap);
 
-        return r < 0 ? r : n_pushed;
+        return r;
 }
 
+#if 0 /// UNNEEDED by elogind
 static int load_env_file_push(
                 const char *filename, unsigned line,
                 const char *key, char *value,
@@ -582,27 +743,19 @@ static int load_env_file_push(
         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;
-        }
+        r = check_utf8ness_and_warn(filename, line, key, value);
+        if (r < 0)
+                return r;
 
-        p = strjoin(key, "=", strempty(value), NULL);
+        p = strjoin(key, "=", value);
         if (!p)
                 return -ENOMEM;
 
-        r = strv_consume(m, p);
-        if (r < 0)
+        r = strv_env_replace(m, p);
+        if (r < 0) {
+                free(p);
                 return r;
+        }
 
         if (n_pushed)
                 (*n_pushed)++;
@@ -627,9 +780,8 @@ int load_env_file(FILE *f, const char *fname, const char *newline, char ***rl) {
         *rl = m;
         return 0;
 }
+#endif // 0
 
-/// UNNEDED by elogind
-#if 0
 static int load_env_file_push_pairs(
                 const char *filename, unsigned line,
                 const char *key, char *value,
@@ -638,19 +790,9 @@ static int load_env_file_push_pairs(
         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 = check_utf8ness_and_warn(filename, line, key, value);
+        if (r < 0)
+                return r;
 
         r = strv_extend(m, key);
         if (r < 0)
@@ -688,7 +830,53 @@ int load_env_file_pairs(FILE *f, const char *fname, const char *newline, char **
         *rl = m;
         return 0;
 }
-#endif // 0
+#if 0 /// UNNEEDED by elogind
+
+static int merge_env_file_push(
+                const char *filename, unsigned line,
+                const char *key, char *value,
+                void *userdata,
+                int *n_pushed) {
+
+        char ***env = userdata;
+        char *expanded_value;
+
+        assert(env);
+
+        if (!value) {
+                log_error("%s:%u: invalid syntax (around \"%s\"), ignoring.", strna(filename), line, key);
+                return 0;
+        }
+
+        if (!env_name_is_valid(key)) {
+                log_error("%s:%u: invalid variable name \"%s\", ignoring.", strna(filename), line, key);
+                free(value);
+                return 0;
+        }
+
+        expanded_value = replace_env(value, *env,
+                                     REPLACE_ENV_USE_ENVIRONMENT|
+                                     REPLACE_ENV_ALLOW_BRACELESS|
+                                     REPLACE_ENV_ALLOW_EXTENDED);
+        if (!expanded_value)
+                return -ENOMEM;
+
+        free_and_replace(value, expanded_value);
+
+        return load_env_file_push(filename, line, key, value, env, n_pushed);
+}
+
+int merge_env_file(
+                char ***env,
+                FILE *f,
+                const char *fname) {
+
+        /* NOTE: this function supports braceful and braceless variable expansions,
+         * plus "extended" substitutions, unlike other exported parsing functions.
+         */
+
+        return parse_env_file_internal(f, fname, NEWLINE, merge_env_file_push, env, NULL);
+}
 
 static void write_env_var(FILE *f, const char *v) {
         const char *p;
@@ -696,29 +884,29 @@ static void write_env_var(FILE *f, const char *v) {
         p = strchr(v, '=');
         if (!p) {
                 /* Fallback */
-                fputs(v, f);
-                fputc('\n', f);
+                fputs_unlocked(v, f);
+                fputc_unlocked('\n', f);
                 return;
         }
 
         p++;
-        fwrite(v, 1, p-v, f);
+        fwrite_unlocked(v, 1, p-v, f);
 
         if (string_has_cc(p, NULL) || chars_intersect(p, WHITESPACE SHELL_NEED_QUOTES)) {
-                fputc('\"', f);
+                fputc_unlocked('\"', f);
 
                 for (; *p; p++) {
                         if (strchr(SHELL_NEED_ESCAPE, *p))
-                                fputc('\\', f);
+                                fputc_unlocked('\\', f);
 
-                        fputc(*p, f);
+                        fputc_unlocked(*p, f);
                 }
 
-                fputc('\"', f);
+                fputc_unlocked('\"', f);
         } else
-                fputs(p, f);
+                fputs_unlocked(p, f);
 
-        fputc('\n', f);
+        fputc_unlocked('\n', f);
 }
 
 int write_env_file(const char *fname, char **l) {
@@ -733,7 +921,8 @@ int write_env_file(const char *fname, char **l) {
         if (r < 0)
                 return r;
 
-        fchmod_umask(fileno(f), 0644);
+        (void) __fsetlocking(f, FSETLOCKING_BYCALLER);
+        (void) fchmod_umask(fileno(f), 0644);
 
         STRV_FOREACH(i, l)
                 write_env_var(f, *i);
@@ -750,17 +939,17 @@ int write_env_file(const char *fname, char **l) {
         return r;
 }
 
-/// UNNEEDED by elogind
-#if 0
 int executable_is_script(const char *path, char **interpreter) {
-        int r;
         _cleanup_free_ char *line = NULL;
-        int len;
+        size_t len;
         char *ans;
+        int r;
 
         assert(path);
 
         r = read_one_line_file(path, &line);
+        if (r == -ENOBUFS) /* First line overly long? if so, then it's not a script */
+                return 0;
         if (r < 0)
                 return r;
 
@@ -784,15 +973,19 @@ 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, *f;
         size_t len;
         int r;
 
+        assert(terminator);
         assert(filename);
         assert(pattern);
         assert(field);
@@ -801,11 +994,31 @@ 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");
 
@@ -818,10 +1031,10 @@ 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, WHITESPACE);
+        len = strcspn(t, terminator);
 
         f = strndup(t, len);
         if (!f)
@@ -830,3 +1043,623 @@ int get_status_field(const char *filename, const char *pattern, char **field) {
         *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 /// UNNEEDED by elogind
+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);
+                else
+                        p = strjoin(*i, "/", path);
+                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 // 0
+
+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;
+}
+
+int fflush_sync_and_check(FILE *f) {
+        int r;
+
+        assert(f);
+
+        r = fflush_and_check(f);
+        if (r < 0)
+                return r;
+
+        if (fsync(fileno(f)) < 0)
+                return -errno;
+
+        r = fsync_directory_of_file(fileno(f));
+        if (r < 0)
+                return r;
+
+        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;
+
+        extra = strempty(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_simplify(t, false);
+        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;
+
+        extra = strempty(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_simplify(t, false);
+        return 0;
+}
+
+#if 0 /// UNNEEDED by elogind
+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;
+        }
+
+        extra = strempty(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_simplify(t, false);
+        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);
+}
+#endif // 0
+
+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;
+}
+
+#if 0 /// UNNEEDED by elogind
+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 = TAKE_PTR(tmp);
+
+        return fd;
+}
+#endif // 0
+
+int open_serialization_fd(const char *ident) {
+        int fd = -1;
+
+        fd = memfd_create(ident, MFD_CLOEXEC);
+        if (fd < 0) {
+                const char *path;
+
+                path = getpid_cached() == 1 ? "/run/systemd" : "/tmp";
+                fd = open_tmpfile_unlinkable(path, O_RDWR|O_CLOEXEC);
+                if (fd < 0)
+                        return fd;
+
+                log_debug("Serializing %s to %s.", ident, path);
+        } else
+                log_debug("Serializing %s to memfd.", ident);
+
+        return fd;
+}
+
+#if 0 /// UNNEEDED by elogind
+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 = TAKE_PTR(x);
+
+        return 0;
+}
+
+int mkdtemp_malloc(const char *template, char **ret) {
+        _cleanup_free_ char *p = NULL;
+        int r;
+
+        assert(ret);
+
+        if (template)
+                p = strdup(template);
+        else {
+                const char *tmp;
+
+                r = tmp_dir(&tmp);
+                if (r < 0)
+                        return r;
+
+                p = strjoin(tmp, "/XXXXXX");
+        }
+        if (!p)
+                return -ENOMEM;
+
+        if (!mkdtemp(p))
+                return -errno;
+
+        *ret = TAKE_PTR(p);
+        return 0;
+}
+#endif // 0
+
+DEFINE_TRIVIAL_CLEANUP_FUNC(FILE*, funlockfile);
+
+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;
+        }
+
+        {
+                _unused_ _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 = TAKE_PTR(buffer);
+        }
+
+        return (int) count;
+}