util: move all to shared/ and split external dependencies in separate internal libraries

Before:
  $ ldd /lib/systemd/systemd-timestamp
  linux-vdso.so.1 =>  (0x00007fffb05ff000)
  libselinux.so.1 => /lib64/libselinux.so.1 (0x00007f90aac57000)
  libcap.so.2 => /lib64/libcap.so.2 (0x00007f90aaa53000)
  librt.so.1 => /lib64/librt.so.1 (0x00007f90aa84a000)
  libc.so.6 => /lib64/libc.so.6 (0x00007f90aa494000)
  /lib64/ld-linux-x86-64.so.2 (0x00007f90aae90000)
  libdl.so.2 => /lib64/libdl.so.2 (0x00007f90aa290000)
  libattr.so.1 => /lib64/libattr.so.1 (0x00007f90aa08a000)
  libpthread.so.0 => /lib64/libpthread.so.0 (0x00007f90a9e6e000)

After:
  $ ldd systemd-timestamp
  linux-vdso.so.1 =>  (0x00007fff3cbff000)
  libselinux.so.1 => /lib64/libselinux.so.1 (0x00007f5eaa1c3000)
  librt.so.1 => /lib64/librt.so.1 (0x00007f5ea9fbb000)
  libc.so.6 => /lib64/libc.so.6 (0x00007f5ea9c04000)
  /lib64/ld-linux-x86-64.so.2 (0x00007f5eaa3fc000)
  libdl.so.2 => /lib64/libdl.so.2 (0x00007f5ea9a00000)
  libpthread.so.0 => /lib64/libpthread.so.0 (0x00007f5ea97e4000)

1 files changed, 135 insertions, 0 deletions

diff --git a/src/shared/conf-parser.h b/src/shared/conf-parser.h
new file mode 100644
index 0000000000..be7d708171
--- /dev/null
+++ b/src/shared/conf-parser.h
@@ -0,0 +1,135 @@
+/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
+
+#ifndef fooconfparserhfoo
+#define fooconfparserhfoo
+
+/***
+  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 General Public License as published by
+  the Free Software Foundation; either version 2 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
+  General Public License for more details.
+
+  You should have received a copy of the GNU General Public License
+  along with systemd; If not, see <http://www.gnu.org/licenses/>.
+***/
+
+#include <stdio.h>
+#include <stdbool.h>
+
+/* An abstract parser for simple, line based, shallow configuration
+ * files consisting of variable assignments only. */
+
+/* Prototype for a parser for a specific configuration setting */
+typedef int (*ConfigParserCallback)(
+                const char *filename,
+                unsigned line,
+                const char *section,
+                const char *lvalue,
+                int ltype,
+                const char *rvalue,
+                void *data,
+                void *userdata);
+
+/* Wraps information for parsing a specific configuration variable, to
+ * be stored in a simple array */
+typedef struct ConfigTableItem {
+        const char *section;            /* Section */
+        const char *lvalue;             /* Name of the variable */
+        ConfigParserCallback parse;     /* Function that is called to parse the variable's value */
+        int ltype;                      /* Distinguish different variables passed to the same callback */
+        void *data;                     /* Where to store the variable's data */
+} ConfigTableItem;
+
+/* Wraps information for parsing a specific configuration variable, to
+ * ve srored in a gperf perfect hashtable */
+typedef struct ConfigPerfItem {
+        const char *section_and_lvalue; /* Section + "." + name of the variable */
+        ConfigParserCallback parse;     /* Function that is called to parse the variable's value */
+        int ltype;                      /* Distinguish different variables passed to the same callback */
+        size_t offset;                  /* Offset where to store data, from the beginning of userdata */
+} ConfigPerfItem;
+
+/* Prototype for a low-level gperf lookup function */
+typedef const ConfigPerfItem* (*ConfigPerfItemLookup)(const char *section_and_lvalue, unsigned length);
+
+/* Prototype for a generic high-level lookup function */
+typedef int (*ConfigItemLookup)(
+                void *table,
+                const char *section,
+                const char *lvalue,
+                ConfigParserCallback *func,
+                int *ltype,
+                void **data,
+                void *userdata);
+
+/* Linear table search implementation of ConfigItemLookup, based on
+ * ConfigTableItem arrays */
+int config_item_table_lookup(void *table, const char *section, const char *lvalue, ConfigParserCallback *func, int *ltype, void **data, void *userdata);
+
+/* gperf implementation of ConfigItemLookup, based on gperf
+ * ConfigPerfItem tables */
+int config_item_perf_lookup(void *table, const char *section, const char *lvalue, ConfigParserCallback *func, int *ltype, void **data, void *userdata);
+
+int config_parse(
+                const char *filename,
+                FILE *f,
+                const char *sections,  /* nulstr */
+                ConfigItemLookup lookup,
+                void *table,
+                bool relaxed,
+                void *userdata);
+
+/* Generic parsers */
+int config_parse_int(const char *filename, unsigned line, const char *section, const char *lvalue, int ltype, const char *rvalue, void *data, void *userdata);
+int config_parse_unsigned(const char *filename, unsigned line, const char *section, const char *lvalue, int ltype, const char *rvalue, void *data, void *userdata);
+int config_parse_long(const char *filename, unsigned line, const char *section, const char *lvalue, int ltype, const char *rvalue, void *data, void *userdata);
+int config_parse_uint64(const char *filename, unsigned line, const char *section, const char *lvalue, int ltype, const char *rvalue, void *data, void *userdata);
+int config_parse_bytes_size(const char *filename, unsigned line, const char *section, const char *lvalue, int ltype, const char *rvalue, void *data, void *userdata);
+int config_parse_bytes_off(const char *filename, unsigned line, const char *section, const char *lvalue, int ltype, const char *rvalue, void *data, void *userdata);
+int config_parse_bool(const char *filename, unsigned line, const char *section, const char *lvalue, int ltype, const char *rvalue, void *data, void *userdata);
+int config_parse_tristate(const char *filename, unsigned line, const char *section, const char *lvalue, int ltype, const char *rvalue, void *data, void *userdata);
+int config_parse_string(const char *filename, unsigned line, const char *section, const char *lvalue, int ltype, const char *rvalue, void *data, void *userdata);
+int config_parse_path(const char *filename, unsigned line, const char *section, const char *lvalue, int ltype, const char *rvalue, void *data, void *userdata);
+int config_parse_strv(const char *filename, unsigned line, const char *section, const char *lvalue, int ltype, const char *rvalue, void *data, void *userdata);
+int config_parse_path_strv(const char *filename, unsigned line, const char *section, const char *lvalue, int ltype, const char *rvalue, void *data, void *userdata);
+int config_parse_usec(const char *filename, unsigned line, const char *section, const char *lvalue, int ltype, const char *rvalue, void *data, void *userdata);
+int config_parse_mode(const char *filename, unsigned line, const char *section, const char *lvalue, int ltype, const char *rvalue, void *data, void *userdata);
+
+#define DEFINE_CONFIG_PARSE_ENUM(function,name,type,msg)                \
+        int function(                                                   \
+                        const char *filename,                           \
+                        unsigned line,                                  \
+                        const char *section,                            \
+                        const char *lvalue,                             \
+                        int ltype,                                      \
+                        const char *rvalue,                             \
+                        void *data,                                     \
+                        void *userdata) {                               \
+                                                                        \
+                type *i = data, x;                                      \
+                                                                        \
+                assert(filename);                                       \
+                assert(lvalue);                                         \
+                assert(rvalue);                                         \
+                assert(data);                                           \
+                                                                        \
+                if ((x = name##_from_string(rvalue)) < 0) {             \
+                        log_error("[%s:%u] " msg ", ignoring: %s", filename, line, rvalue); \
+                        return 0;                                       \
+                }                                                       \
+                                                                        \
+                *i = x;                                                 \
+                                                                        \
+                return 0;                                               \
+        }
+
+#endif