openrc/src/librc-misc.c

/*
   rc-misc.c
   rc misc functions
   Copyright 2007 Gentoo Foundation
   */

#include <sys/types.h>
#include <sys/stat.h>
#include <sys/utsname.h>

#include <dirent.h>
#include <errno.h>
#include <limits.h>
#include <regex.h>
#include <stdarg.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>

#include "einfo.h"
#include "rc-misc.h"
#include "rc.h"
#include "strlist.h"

#define ERRX 		eerrorx("out of memory");

#define PROFILE_ENV	"/etc/profile.env"
#define SYS_WHITELIST	RC_LIBDIR "conf.d/env_whitelist"
#define USR_WHITELIST	"/etc/conf.d/env_whitelist"
#define RC_CONFIG	"/etc/conf.d/rc"

#define PATH_PREFIX 	RC_LIBDIR "bin:/bin:/sbin:/usr/bin:/usr/sbin"

#ifndef S_IXUGO
# define S_IXUGO (S_IXUSR | S_IXGRP | S_IXOTH)
#endif

void *rc_xcalloc (size_t n, size_t size)
{
	void *value = calloc (n, size);

	if (value)
		return value;

	ERRX
}

void *rc_xmalloc (size_t size)
{
	void *value = malloc (size);

	if (value)
		return (value);

	ERRX
}

void *rc_xrealloc (void *ptr, size_t size)
{
	void *value = realloc (ptr, size);

	if (value)
		return (value);

	ERRX
}


char *rc_xstrdup (const char *str)
{
	char *value;

	if (! str)
		return (NULL);

	value = strdup (str);

	if (value)
		return (value);

	ERRX
}

bool rc_is_env (const char *var, const char *val)
{
	char *v;

	if (! var)
		return (false);

	v = getenv (var);
	if (! v)
		return (val == NULL ? true : false);

	return (strcasecmp (v, val) == 0 ? true : false);
}

char *rc_strcatpaths (const char *path1, const char *paths, ...)
{
	va_list ap;
	int length;
	int i;
	char *p;
	char *path;
	char *pathp;

	if (! path1 || ! paths)
		return (NULL);

	length = strlen (path1) + strlen (paths) + 3;
	i = 0;
	va_start (ap, paths);
	while ((p = va_arg (ap, char *)) != NULL)
		length += strlen (p) + 1;
	va_end (ap);

	path = rc_xmalloc (length);
	memset (path, 0, length);
	memcpy (path, path1, strlen (path1));
	pathp = path + strlen (path1) - 1;
	if (*pathp != '/') {
		pathp++;
		*pathp++ = '/';
	}
	else
		pathp++;
	memcpy (pathp, paths, strlen (paths));
	pathp += strlen (paths);

	va_start (ap, paths);
	while ((p = va_arg (ap, char *)) != NULL) {
		if (*pathp != '/')
			*pathp++ = '/';
		i = strlen (p);
		memcpy (pathp, p, i);
		pathp += i;
	}
	va_end (ap);

	*pathp++ = 0;

	return (path);
}

bool rc_exists (const char *pathname)
{
	struct stat buf;

	if (! pathname)
		return (false);

	if (stat (pathname, &buf) == 0)
		return (true);

	errno = 0;
	return (false);
}

bool rc_is_file (const char *pathname)
{
	struct stat buf;

	if (! pathname)
		return (false);

	if (stat (pathname, &buf) == 0)
		return (S_ISREG (buf.st_mode));

	errno = 0;
	return (false);
}

bool rc_is_dir (const char *pathname)
{
	struct stat buf;

	if (! pathname)
		return (false); 

	if (stat (pathname, &buf) == 0)
		return (S_ISDIR (buf.st_mode));

	errno = 0;
	return (false);
}

bool rc_is_link (const char *pathname)
{
	struct stat buf;

	if (! pathname)
		return (false); 

	if (lstat (pathname, &buf) == 0)
		return (S_ISLNK (buf.st_mode));

	errno = 0;
	return (false);
}

bool rc_is_exec (const char *pathname)
{
	struct stat buf;

	if (! pathname)
		return (false);

	if (lstat (pathname, &buf) == 0)
		return (buf.st_mode & S_IXUGO);

	errno = 0;
	return (false);
}

char **rc_ls_dir (char **list, const char *dir, int options)
{
	DIR *dp;
	struct dirent *d;

	if (! dir)
		return (list);

	if ((dp = opendir (dir)) == NULL) {
		eerror ("failed to opendir `%s': %s", dir, strerror (errno));
		return (list);
	}

	errno = 0;
	while (((d = readdir (dp)) != NULL) && errno == 0) {
		if (d->d_name[0] != '.') {
			if (options & RC_LS_INITD) {
				int l = strlen (d->d_name);
				char *init = rc_strcatpaths (RC_INITDIR, d->d_name,
											 (char *) NULL);
				bool ok = rc_exists (init);
				free (init);
				if (! ok)
					continue;

				/* .sh files are not init scripts */
				if (l > 2 && d->d_name[l - 3] == '.' &&
					d->d_name[l - 2] == 's' &&
					d->d_name[l - 1] == 'h')
					continue;
			}
			list = rc_strlist_addsort (list, d->d_name);
		}
	}
	closedir (dp);

	if (errno != 0)	{
		eerror ("failed to readdir `%s': %s", dir, strerror (errno));
		rc_strlist_free (list);
		return (NULL);
	}

	return (list);
}

bool rc_rm_dir (const char *pathname, bool top)
{
	DIR *dp;
	struct dirent *d;

	if (! pathname)
		return (false);

	if ((dp = opendir (pathname)) == NULL) {
		eerror ("failed to opendir `%s': %s", pathname, strerror (errno));
		return (false);
	}

	errno = 0;
	while (((d = readdir (dp)) != NULL) && errno == 0) {
		if (strcmp (d->d_name, ".") != 0 && strcmp (d->d_name, "..") != 0) {
			char *tmp = rc_strcatpaths (pathname, d->d_name, (char *) NULL);
			if (d->d_type == DT_DIR) {
				if (! rc_rm_dir (tmp, true))
				{
					free (tmp);
					closedir (dp);
					return (false);
				}
			} else {
				if (unlink (tmp)) {
					eerror ("failed to unlink `%s': %s", tmp, strerror (errno));
					free (tmp);
					closedir (dp);
					return (false);
				}
			}
			free (tmp);
		}
	}
	if (errno != 0)
		eerror ("failed to readdir `%s': %s", pathname, strerror (errno));
	closedir (dp);

	if (top && rmdir (pathname) != 0) {
		eerror ("failed to rmdir `%s': %s", pathname, strerror (errno));
		return false;
	}

	return (true);
}

char **rc_get_config (char **list, const char *file)
{
	FILE *fp;
	char buffer[RC_LINEBUFFER];
	char *p;
	char *token;
	char *line;
	char *linep;
	char *linetok;
	int i = 0;
	bool replaced;
	char *entry;
	char *newline;

	if (! (fp = fopen (file, "r"))) {
		ewarn ("load_config_file `%s': %s", file, strerror (errno));
		return (list);
	}

	while (fgets (buffer, RC_LINEBUFFER, fp)) {
		p = buffer;

		/* Strip leading spaces/tabs */
		while ((*p == ' ') || (*p == '\t'))
			p++;

		if (! p || strlen (p) < 3 || p[0] == '#')
			continue;

		/* Get entry */
		token = strsep (&p, "=");
		if (! token)
			continue;

		entry = rc_xstrdup (token);

		do {
			/* Bash variables are usually quoted */
			token = strsep (&p, "\"\'");
		} while ((token) && (strlen (token) == 0));

		/* Drop a newline if that's all we have */
		i = strlen (token) - 1;
		if (token[i] == 10)
			token[i] = 0;

		i = strlen (entry) + strlen (token) + 2;
		newline = rc_xmalloc (i);
		snprintf (newline, i, "%s=%s", entry, token);

		replaced = false;
		/* In shells the last item takes precedence, so we need to remove
		   any prior values we may already have */
		STRLIST_FOREACH (list, line, i) {
			char *tmp = rc_xstrdup (line);
			linep = tmp; 
			linetok = strsep (&linep, "=");
			if (strcmp (linetok, entry) == 0) {
				/* We have a match now - to save time we directly replace it */
				free (list[i - 1]);
				list[i - 1] = newline; 
				replaced = true;
				free (tmp);
				break;
			}
			free (tmp);
		}

		if (! replaced) {
			list = rc_strlist_addsort (list, newline);
			free (newline);
		}
		free (entry);
	}
	fclose (fp);

	return (list);
}

char *rc_get_config_entry (char **list, const char *entry)
{
	char *line;
	int i;
	char *p;

	STRLIST_FOREACH (list, line, i) {
		p = strchr (line, '=');
		if (p && strncmp (entry, line, p - line) == 0)
			return (p += 1);
	}

	return (NULL);
}

char **rc_get_list (char **list, const char *file)
{
	FILE *fp;
	char buffer[RC_LINEBUFFER];
	char *p;
	char *token;

	if (! (fp = fopen (file, "r"))) {
		ewarn ("rc_get_list `%s': %s", file, strerror (errno));
		return (list);
	}

	while (fgets (buffer, RC_LINEBUFFER, fp)) {
		p = buffer;

		/* Strip leading spaces/tabs */
		while ((*p == ' ') || (*p == '\t'))
			p++;

		/* Get entry - we do not want comments */
		token = strsep (&p, "#");
		if (token && (strlen (token) > 1)) {
			/* Stip the newline if present */
			if (token[strlen (token) - 1] == '\n')
				token[strlen (token) - 1] = 0;

			list = rc_strlist_add (list, token);
		}
	}
	fclose (fp);

	return (list);
}

char **rc_filter_env (void)
{
	char **env = NULL;
	char **whitelist = NULL;
	char *env_name = NULL;
	char **profile = NULL;
	int count = 0;
	bool got_path = false;
	char *env_var;
	int env_len;
	char *p;
	char *token;
	char *sep;
	char *e;
	int pplen = strlen (PATH_PREFIX);

	whitelist = rc_get_list (whitelist, SYS_WHITELIST);
	if (! whitelist)
		ewarn ("system environment whitelist (" SYS_WHITELIST ") missing");

	whitelist = rc_get_list (whitelist, USR_WHITELIST);

	if (! whitelist)
		return (NULL);

	if (rc_is_file (PROFILE_ENV))
		profile = rc_get_config (profile, PROFILE_ENV);

	STRLIST_FOREACH (whitelist, env_name, count) {
		char *space = strchr (env_name, ' ');
		if (space)
			*space = 0;

		env_var = getenv (env_name);

		if (! env_var && profile) {
			env_len = strlen (env_name) + strlen ("export ") + 1;
			p = rc_xmalloc (sizeof (char *) * env_len);
			snprintf (p, env_len, "export %s", env_name);
			env_var = rc_get_config_entry (profile, p);
			free (p);
		}

		if (! env_var)
			continue;

		/* Ensure our PATH is prefixed with the system locations first
		   for a little extra security */
		if (strcmp (env_name, "PATH") == 0 &&
			strncmp (PATH_PREFIX, env_var, pplen) != 0)
		{
			got_path = true;
			env_len = strlen (env_name) + strlen (env_var) + pplen + 2;
			e = p = rc_xmalloc (sizeof (char *) * env_len);
			p += snprintf (e, env_len, "%s=%s", env_name, PATH_PREFIX);

			/* Now go through the env var and only add bits not in our PREFIX */
			sep = env_var;
			while ((token = strsep (&sep, ":"))) {
				char *np = strdup (PATH_PREFIX);
				char *npp = np;
				char *tok = NULL;
				while ((tok = strsep (&npp, ":")))
					if (strcmp (tok, token) == 0)
						break;
				if (! tok)
					p += snprintf (p, env_len - (p - e), ":%s", token);
				free (np);
			}
			*p++ = 0;
		} else {
			env_len = strlen (env_name) + strlen (env_var) + 2;
			e = rc_xmalloc (sizeof (char *) * env_len);
			snprintf (e, env_len, "%s=%s", env_name, env_var);
		}

		env = rc_strlist_add (env, e);
		free (e);
	}

	/* We filtered the env but didn't get a PATH? Very odd.
	   However, we do need a path, so use a default. */
	if (! got_path) {
		env_len = strlen ("PATH=") + strlen (PATH_PREFIX) + 2;
		p = rc_xmalloc (sizeof (char *) * env_len);
		snprintf (p, env_len, "PATH=%s", PATH_PREFIX);
		env = rc_strlist_add (env, p);
		free (p);
	}

	rc_strlist_free (whitelist);
	rc_strlist_free (profile);

	return (env);
}

/* Other systems may need this at some point, but for now it's Linux only */
#ifdef __linux__
static bool file_regex (const char *file, const char *regex)
{
	FILE *fp;
	char buffer[RC_LINEBUFFER];
	regex_t re;
	bool retval = false;
	int result;

	if (! rc_exists (file))
		return (false);

	if (! (fp = fopen (file, "r"))) {
		ewarn ("file_regex `%s': %s", file, strerror (errno));
		return (false);
	}

	if ((result = regcomp (&re, regex, REG_EXTENDED | REG_NOSUB)) != 0) {
		fclose (fp);
		regerror (result, &re, buffer, sizeof (buffer));
		eerror ("file_regex: %s", buffer);
		return (false);
	}

	while (fgets (buffer, RC_LINEBUFFER, fp)) {
		if (regexec (&re, buffer, 0, NULL, 0) == 0)
		{
			retval = true;
			break;
		}
	}
	fclose (fp);
	regfree (&re);

	return (retval);
}
#endif

char **rc_config_env (char **env)
{
	char *line;
	int i;
	char *p;
	char **config = rc_get_config (NULL, RC_CONFIG);
	char *e;
	char sys[6];
	struct utsname uts;
	bool has_net_fs_list = false;
	FILE *fp;
	char buffer[PATH_MAX];

	STRLIST_FOREACH (config, line, i) {
		p = strchr (line, '=');
		if (! p)
			continue;

		*p = 0;
		e = getenv (line);
		if (! e) {
			*p = '=';
			env = rc_strlist_add (env, line);
		} else {
			int len = strlen (line) + strlen (e) + 2;
			char *new = rc_xmalloc (sizeof (char *) * len);
			snprintf (new, len, "%s=%s", line, e);
			env = rc_strlist_add (env, new);
			free (new);
		}
	}
	rc_strlist_free (config);

	/* One char less to drop the trailing / */
	i = strlen ("RC_LIBDIR=") + strlen (RC_LIBDIR);
	line = rc_xmalloc (sizeof (char *) * i);
	snprintf (line, i, "RC_LIBDIR=" RC_LIBDIR);
	env = rc_strlist_add (env, line);
	free (line);

	/* One char less to drop the trailing / */
	i = strlen ("RC_SVCDIR=") + strlen (RC_SVCDIR);
	line = rc_xmalloc (sizeof (char *) * i);
	snprintf (line, i, "RC_SVCDIR=" RC_SVCDIR);
	env = rc_strlist_add (env, line);
	free (line);

	env = rc_strlist_add (env, "RC_BOOTLEVEL=" RC_LEVEL_BOOT);

	p = rc_get_runlevel ();
	i = strlen ("RC_SOFTLEVEL=") + strlen (p) + 1;
	line = rc_xmalloc (sizeof (char *) * i);
	snprintf (line, i, "RC_SOFTLEVEL=%s", p);
	env = rc_strlist_add (env, line);
	free (line);

	if (rc_exists (RC_SVCDIR "ksoftlevel")) {
		if (! (fp = fopen (RC_SVCDIR "ksoftlevel", "r")))
			eerror ("fopen `%s': %s", RC_SVCDIR "ksoftlevel",
					strerror (errno));
		else {
			memset (buffer, 0, sizeof (buffer));
			if (fgets (buffer, sizeof (buffer), fp)) {
				i = strlen (buffer) - 1;
				if (buffer[i] == '\n')
					buffer[i] = 0;
				i += strlen ("RC_DEFAULTLEVEL=") + 2;
				line = rc_xmalloc (sizeof (char *) * i);
				snprintf (line, i, "RC_DEFAULTLEVEL=%s", buffer);
				env = rc_strlist_add (env, line);
				free (line);
			}
			fclose (fp);
		}
	} else
		env = rc_strlist_add (env, "RC_DEFAULTLEVEL=" RC_LEVEL_DEFAULT);

	memset (sys, 0, sizeof (sys));

	/* Linux can run some funky stuff like Xen, VServer, UML, etc
	   We store this special system in RC_SYS so our scripts run fast */
#ifdef __linux__
	if (rc_is_dir ("/proc/xen")) {
		fp = fopen ("/proc/xen/capabilities", "r");
		if (fp) {
			fclose (fp);
			if (file_regex ("/proc/xen/capabilities", "control_d"))
				snprintf (sys, sizeof (sys), "XENU");
		}
		if (! sys)
			snprintf (sys, sizeof (sys), "XEN0");
	} else if (file_regex ("/proc/cpuinfo", "UML"))
		snprintf (sys, sizeof (sys), "UML");
	else if (file_regex ("/proc/self/status",
						 "(s_context|VxID|envID):[[:space:]]*[1-9]"))
													snprintf (sys, sizeof (sys), "VPS"); 
#endif

	/* Only add a NET_FS list if not defined */
	STRLIST_FOREACH (env, line, i)
		if (strncmp (line, "RC_NET_FS_LIST=", strlen ("RC_NET_FS_LIST=")) == 0) {
			has_net_fs_list = true;
			break;
		}

	if (! has_net_fs_list) {
		i = strlen ("RC_NET_FS_LIST=") + strlen (RC_NET_FS_LIST_DEFAULT) + 1;
		line = rc_xmalloc (sizeof (char *) * i);
		snprintf (line, i, "RC_NET_FS_LIST=%s", RC_NET_FS_LIST_DEFAULT);
		env = rc_strlist_add (env, line);
		free (line);
	}

	if (sys[0]) {
		i = strlen ("RC_SYS=") + strlen (sys) + 2;
		line = rc_xmalloc (sizeof (char *) * i);
		snprintf (line, i, "RC_SYS=%s", sys);
		env = rc_strlist_add (env, line);
		free (line);
	}

	/* Some scripts may need to take a different code path if Linux/FreeBSD, etc
	   To save on calling uname, we store it in an environment variable */
	if (uname (&uts) == 0) {
		i = strlen ("RC_UNAME=") + strlen (uts.sysname) + 2;
		line = rc_xmalloc (sizeof (char *) * i);
		snprintf (line, i, "RC_UNAME=%s", uts.sysname);
		env = rc_strlist_add (env, line);
		free (line);
	}

	return (env);
}