hooks.c revision 1031614c095f00454326deb460a83381e98d5166 
1/*
2 * This file is part of ltrace.
3 * Copyright (C) 2012, 2013 Petr Machata
4 *
5 * This program is free software; you can redistribute it and/or
6 * modify it under the terms of the GNU General Public License as
7 * published by the Free Software Foundation; either version 2 of the
8 * License, or (at your option) any later version.
9 *
10 * This program is distributed in the hope that it will be useful, but
11 * WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
13 * General Public License for more details.
14 *
15 * You should have received a copy of the GNU General Public License
16 * along with this program; if not, write to the Free Software
17 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
18 * 02110-1301 USA
19 */
20
21#define _POSIX_C_SOURCE 200809L
22#include <sys/types.h>
23#include <alloca.h>
24#include <errno.h>
25#include <pwd.h>
26#include <stdio.h>
27#include <stdlib.h>
28#include <string.h>
29#include <unistd.h>
30
31#include "backend.h"
32#include "dict.h"
33#include "options.h"
34#include "sysdep.h"
35#include "vect.h"
36
37static char *
38append(const char *str1, const char *str2)
39{
40	char *ret = malloc(strlen(str1) + strlen(str2) + 2);
41	if (ret == NULL)
42		return ret;
43	/* BEGIN android-changed */
44	strcpy(ret, str1);
45	strcat(ret, str2);
46	/* END android-changed */
47	return ret;
48}
49
50static void
51add_dir(struct vect *dirs, const char *str1, const char *str2)
52{
53	char *dir = append(str1, str2);
54	if (dir != NULL
55	    && VECT_PUSHBACK(dirs, &dir) < 0)
56		fprintf(stderr,
57			"Couldn't store candidate config directory %s%s: %s.\n",
58			str1, str2, strerror(errno));
59}
60
61static enum callback_status
62add_dir_component_cb(struct opt_F_t *entry, void *data)
63{
64	struct vect *dirs = data;
65	if (opt_F_get_kind(entry) == OPT_F_DIR)
66		add_dir(dirs, entry->pathname, "/ltrace");
67	return CBS_CONT;
68}
69
70static void
71destroy_opt_F_cb(struct opt_F_t *entry, void *data)
72{
73	opt_F_destroy(entry);
74}
75
76static char *g_home_dir = NULL;
77
78int
79os_get_config_dirs(int private, const char ***retp)
80{
81	/* Vector of char *.  Contains first pointers to local paths,
82	 * then NULL, then pointers to system paths, then another
83	 * NULL.  SYS_START points to the beginning of the second
84	 * part.  */
85	static struct vect dirs;
86	static ssize_t sys_start = 0;
87
88again:
89	if (sys_start != 0) {
90		if (sys_start == -1)
91			return -1;
92
93		if (retp != NULL) {
94			if (private)
95				*retp = VECT_ELEMENT(&dirs, const char *, 0);
96			else
97				*retp = VECT_ELEMENT(&dirs, const char *,
98						     (size_t)sys_start);
99		}
100
101		return 0;
102	}
103
104	VECT_INIT(&dirs, char *);
105
106	char *home = getenv("HOME");
107	if (home == NULL) {
108		struct passwd *pwd = getpwuid(getuid());
109		if (pwd != NULL)
110			home = pwd->pw_dir;
111	}
112
113	size_t home_len = home != NULL ? strlen(home) : 0;
114
115	/* The values coming from getenv and getpwuid may not be
116	 * persistent.  */
117	if (home != NULL) {
118		free(g_home_dir);
119		g_home_dir = strdup(home);
120		if (g_home_dir != NULL) {
121			home = g_home_dir;
122		} else {
123			char *tmp = alloca(home_len + 1);
124			strcpy(tmp, home);
125			home = tmp;
126		}
127	}
128
129	char *xdg_home = getenv("XDG_CONFIG_HOME");
130	if (xdg_home == NULL && home != NULL) {
131		xdg_home = alloca(home_len + sizeof "/.config");
132		sprintf(xdg_home, "%s/.config", home);
133	}
134	if (xdg_home != NULL)
135		add_dir(&dirs, xdg_home, "/ltrace");
136	if (home != NULL)
137		add_dir(&dirs, home, "/.ltrace");
138
139	char *delim = NULL;
140	if (VECT_PUSHBACK(&dirs, &delim) < 0) {
141	fail:
142		/* This can't work :(  */
143		fprintf(stderr,
144			"Couldn't initialize list of config directories: %s.\n",
145			strerror(errno));
146		VECT_DESTROY(&dirs, const char *, dict_dtor_string, NULL);
147		sys_start = -1;
148		return -1;
149	}
150	sys_start = vect_size(&dirs);
151
152	/* """preference-ordered set of base directories to search for
153	 * configuration files in addition to the $XDG_CONFIG_HOME
154	 * base directory. The directories in $XDG_CONFIG_DIRS should
155	 * be seperated with a colon ':'."""  */
156	char *xdg_sys = getenv("XDG_CONFIG_DIRS");
157	if (xdg_sys != NULL) {
158		struct vect v;
159		VECT_INIT(&v, struct opt_F_t);
160		if (parse_colon_separated_list(xdg_sys, &v) < 0
161		    || VECT_EACH(&v, struct opt_F_t, NULL,
162				 add_dir_component_cb, &dirs) != NULL)
163			fprintf(stderr,
164				"Error processing $XDG_CONFIG_DIRS '%s': %s\n",
165				xdg_sys, strerror(errno));
166		VECT_DESTROY(&v, struct opt_F_t, destroy_opt_F_cb, NULL);
167	}
168
169	/* PKGDATADIR is passed via -D when compiling.  */
170	const char *pkgdatadir = PKGDATADIR;
171	if (pkgdatadir != NULL)
172		add_dir(&dirs, pkgdatadir, "");
173
174	if (VECT_PUSHBACK(&dirs, &delim) < 0)
175		goto fail;
176
177	goto again;
178}
179
180int
181os_get_ltrace_conf_filenames(struct vect *retp)
182{
183	char *homepath = NULL;
184	char *syspath = NULL;
185
186#define FN ".ltrace.conf"
187	if (g_home_dir == NULL)
188		os_get_config_dirs(0, NULL);
189
190	if (g_home_dir != NULL) {
191		homepath = malloc(strlen(g_home_dir) + 1 + sizeof FN);
192		if (homepath == NULL
193		    || sprintf(homepath, "%s/%s", g_home_dir, FN) < 0) {
194		fail:
195			free(syspath);
196			free(homepath);
197			return -1;
198		}
199	}
200
201	/* SYSCONFDIR is passed via -D when compiling.  */
202	const char *sysconfdir = SYSCONFDIR;
203	if (sysconfdir != NULL && *sysconfdir != '\0') {
204		/* No +1, we skip the initial period.  */
205		syspath = malloc(strlen(sysconfdir) + sizeof FN);
206		if (syspath == NULL
207		    || sprintf(syspath, "%s/%s", sysconfdir, FN + 1) < 0)
208			goto fail;
209	}
210
211	if (VECT_PUSHBACK(retp, &homepath) < 0
212	    || VECT_PUSHBACK(retp, &syspath) < 0)
213		goto fail;
214
215	return 0;
216}
217