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1cf4a0eb8

Denis Vlasenko

2009-04-22

FAILED Duration: 34s

Subject

httpd: simplify insane conf file parser

Binary

No binary (build failed)

Architecture & Compiler Flags

Architecture: x86_64-linux-gnu Compiler: gcc (Ubuntu 11.4.0-1ubuntu1~22.04.3) 11.4.0

—

Build Log

(log yok)

Commit Diff GitHub →

include/libbb.h +2 -0 libbb/simplify_path.c +19 -13 networking/httpd.c +173 -175

include/libbb.h+2 -0

@@ -1093,6 +1093,8 @@ const char *get_signame(int number) FAST_FUNC;
	void print_signames(void) FAST_FUNC;

	char bb_simplify_path(const char path) FAST_FUNC;
+	/* Returns ptr to NUL */
+	char bb_simplify_abs_path_inplace(char path) FAST_FUNC;

	#define FAIL_DELAY 3
	extern void bb_do_delay(int seconds) FAST_FUNC;

libbb/simplify_path.c+19 -13

@@ -6,22 +6,13 @@
	*
	* Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
	*/
-
	#include "libbb.h"

-	char* FAST_FUNC bb_simplify_path(const char *path)
+	char* FAST_FUNC bb_simplify_abs_path_inplace(char *start)
	{
-	char s, start, *p;
+	char s, p;

-	if (path[0] == '/')
-	start = xstrdup(path);
-	else {
-	s = xrealloc_getcwd_or_warn(NULL);
-	start = concat_path_file(s, path);
-	free(s);
-	}
	p = s = start;
-
	do {
	if (*p == '/') {
	if (s == '/') { / skip duplicate (or initial) slash */
@@ -47,7 +38,22 @@ char* FAST_FUNC bb_simplify_path(const char *path)
	if ((p == start) \|\| (p != '/')) { / not a trailing slash */
	++p; /* so keep last character */
	}
-	*p = 0;
+	*p = '\0';
+	return p;
+	}
+
+	char* FAST_FUNC bb_simplify_path(const char *path)
+	{
+	char s, p;
+
+	if (path[0] == '/')
+	s = xstrdup(path);
+	else {
+	p = xrealloc_getcwd_or_warn(NULL);
+	s = concat_path_file(p, path);
+	free(p);
+	}

-	return start;
+	bb_simplify_abs_path_inplace(s);
+	return s;
	}

networking/httpd.c+173 -175

@@ -54,7 +54,7 @@
	* /adm:admin:setup # Require user admin, pwd setup on urls starting with /adm/
	* /adm:toor:PaSsWd # or user toor, pwd PaSsWd on urls starting with /adm/
	* .au:audio/basic # additional mime type for audio.au files
-	* *.php:/path/php # running cgi.php scripts through an interpreter
+	* *.php:/path/php # run xxx.php through an interpreter
	*
	* A/D may be as a/d or allow/deny - only first char matters.
	* Deny/Allow IP logic:
@@ -115,8 +115,8 @@

	#define HEADER_READ_TIMEOUT 60

-	static const char default_path_httpd_conf[] ALIGN1 = "/etc";
-	static const char httpd_conf[] ALIGN1 = "httpd.conf";
+	static const char DEFAULT_PATH_HTTPD_CONF[] ALIGN1 = "/etc";
+	static const char HTTPD_CONF[] ALIGN1 = "httpd.conf";
	static const char HTTP_200[] ALIGN1 = "HTTP/1.0 200 OK\r\n";

	typedef struct has_next_ptr {
@@ -242,7 +242,7 @@ struct globals {
	const char *bind_addr_or_port;

	const char *g_query;
-	const char *configFile;
+	const char *opt_c_configFile;
	const char *home_httpd;
	const char *index_page;

@@ -289,7 +289,7 @@ struct globals {
	#define rmt_ip (G.rmt_ip )
	#define bind_addr_or_port (G.bind_addr_or_port)
	#define g_query (G.g_query )
-	#define configFile (G.configFile )
+	#define opt_c_configFile (G.opt_c_configFile )
	#define home_httpd (G.home_httpd )
	#define index_page (G.index_page )
	#define found_mime_type (G.found_mime_type )
@@ -452,14 +452,6 @@ static int scan_ip_mask(const char str, unsigned ipp, unsigned *maskp)
	/*
	* Parse configuration file into in-memory linked list.
	*
-	* The first non-white character is examined to determine if the config line
-	* is one of the following:
-	* .ext:mime/type # new mime type not compiled into httpd
-	* [adAD]:from # ip address allow/deny, * for wildcard
-	* /path:user:pass # username/password
-	* Ennn:error.html # error page for status nnn
-	* P:/url:[http://]hostname[:port]/new/path # reverse proxy
-	*
	* Any previous IP rules are discarded.
	* If the flag argument is not SUBDIR_PARSE then all /path and mime rules
	* are also discarded. That is, previous settings are retained if flag is
@@ -469,99 +461,136 @@ static int scan_ip_mask(const char str, unsigned ipp, unsigned *maskp)
	* path Path where to look for httpd.conf (without filename).
	* flag Type of the parse request.
	*/
-	/* flag */
-	#define FIRST_PARSE 0
-	#define SUBDIR_PARSE 1
-	#define SIGNALED_PARSE 2
-	#define FIND_FROM_HTTPD_ROOT 3
+	/* flag param: */
+	enum {
+	FIRST_PARSE = 0, /* path will be "/etc" */
+	SIGNALED_PARSE = 1, /* path will be "/etc" */
+	SUBDIR_PARSE = 2, /* path will be derived from URL */
+	};
	static void parse_conf(const char *path, int flag)
	{
+	/* internally used extra flag state */
+	enum { TRY_CURDIR_PARSE = 3 };
+
	FILE *f;
-	#if ENABLE_FEATURE_HTTPD_BASIC_AUTH
-	Htaccess *prev;
-	#endif
-	Htaccess *cur;
-	const char *filename = configFile;
+	const char *filename;
	char buf[160];
-	char p, p0;
-	char *after_colon;
-	Htaccess_IP *pip;

	/* discard old rules */
	free_Htaccess_IP_list(&ip_a_d);
	flg_deny_all = 0;
	/* retain previous auth and mime config only for subdir parse */
	if (flag != SUBDIR_PARSE) {
+	free_Htaccess_list(&mime_a);
	#if ENABLE_FEATURE_HTTPD_BASIC_AUTH
	free_Htaccess_list(&g_auth);
	#endif
-	free_Htaccess_list(&mime_a);
	#if ENABLE_FEATURE_HTTPD_CONFIG_WITH_SCRIPT_INTERPR
	free_Htaccess_list(&script_i);
	#endif
	}

+	filename = opt_c_configFile;
	if (flag == SUBDIR_PARSE \|\| filename == NULL) {
-	filename = alloca(strlen(path) + sizeof(httpd_conf) + 2);
-	sprintf((char *)filename, "%s/%s", path, httpd_conf);
+	filename = alloca(strlen(path) + sizeof(HTTPD_CONF) + 2);
+	sprintf((char *)filename, "%s/%s", path, HTTPD_CONF);
	}

	while ((f = fopen_for_read(filename)) == NULL) {
-	if (flag == SUBDIR_PARSE \|\| flag == FIND_FROM_HTTPD_ROOT) {
+	if (flag >= SUBDIR_PARSE) { /* SUBDIR or TRY_CURDIR */
	/* config file not found, no changes to config */
	return;
	}
-	if (configFile && flag == FIRST_PARSE) /* if -c option given */
-	bb_simple_perror_msg_and_die(filename);
-	flag = FIND_FROM_HTTPD_ROOT;
-	filename = httpd_conf;
+	if (flag == FIRST_PARSE) {
+	/* -c CONFFILE given, but CONFFILE doesn't exist? */
+	if (opt_c_configFile)
+	bb_simple_perror_msg_and_die(opt_c_configFile);
+	/* else: no -c, thus we looked at /etc/httpd.conf,
+	* and it's not there. try ./httpd.conf: */
+	}
+	flag = TRY_CURDIR_PARSE;
+	filename = HTTPD_CONF;
	}

	#if ENABLE_FEATURE_HTTPD_BASIC_AUTH
-	prev = g_auth;
-	#endif
-	/* This could stand some work */
-	while ((p0 = fgets(buf, sizeof(buf), f)) != NULL) {
-	after_colon = NULL;
-	for (p = p0; p0 != '\0' && p0 != '#'; p0++) {
-	if (!isspace(*p0)) {
-	p++ = p0;
-	if (*p0 == ':' && after_colon == NULL)
-	after_colon = p;
+	/* in "/file:user:pass" lines, we prepend path in subdirs */
+	if (flag != SUBDIR_PARSE)
+	path = "";
+	#endif
+	/* The lines can be:
+	*
+	* I:default_index_file
+	* H:http_home
+	* [AD]:IP[/mask] # allow/deny, * for wildcard
+	* Ennn:error.html # error page for status nnn
+	* P:/url:[http://]hostname[:port]/new/path # reverse proxy
+	* .ext:mime/type # mime type
+	* *.php:/path/php # run xxx.php through an interpreter
+	* /file:user:pass # username and password
+	*/
+	while (fgets(buf, sizeof(buf), f) != NULL) {
+	unsigned strlen_buf;
+	unsigned char ch;
+	char *after_colon = NULL;
+
+	{ /* remove all whitespace, and # comments */
+	char p, p0;
+
+	p = p0 = buf;
+	while ((ch = *p0++) != '\0' && ch != '#') {
+	if (!isspace(ch)) {
+	*p++ = ch;
+	if (ch == ':' && after_colon == NULL)
+	after_colon = p;
+	}
	}
+	*p = '\0';
+	strlen_buf = p - buf;
	}
-	*p = '\0';

-	/* test for empty or strange line */
+	/* empty or strange line? */
	if (after_colon == NULL \|\| *after_colon == '\0')
+	goto config_error;
+
+	ch = (buf[0] & ~0x20); /* toupper if it's a letter */
+
+	if (ch == 'I') {
+	index_page = xstrdup(after_colon);
	continue;
-	p0 = buf;
-	if (p0 == 'd' \|\| p0 == 'a')
-	p0 -= 0x20; / a/d -> A/D */
-	if (after_colon == '') {
-	if (*p0 == 'D') {
-	/* memorize "deny all" */
-	flg_deny_all = 1;
-	}
-	/* skip assumed "A:", it is a default anyway /
+	}
+
+	/* do not allow jumping around using H in subdir's configs */
+	if (flag == FIRST_PARSE && ch == 'H') {
+	home_httpd = xstrdup(after_colon);
+	xchdir(home_httpd);
	continue;
	}

-	if (p0 == 'A' \|\| p0 == 'D') {
-	/* storing current config IP line */
-	pip = xzalloc(sizeof(Htaccess_IP));
-	if (scan_ip_mask(after_colon, &(pip->ip), &(pip->mask))) {
+	if (ch == 'A' \|\| ch == 'D') {
+	Htaccess_IP *pip;
+
+	if (after_colon == '') {
+	if (ch == 'D') {
+	/* memorize "deny all" */
+	flg_deny_all = 1;
+	}
+	/* skip assumed "A:", it is a default anyway /
+	continue;
+	}
+	/* store "allow/deny IP/mask" line */
+	pip = xzalloc(sizeof(*pip));
+	if (scan_ip_mask(after_colon, &pip->ip, &pip->mask)) {
	/* IP{/mask} syntax error detected, protect all */
-	*p0 = 'D';
+	ch = 'D';
	pip->mask = 0;
	}
-	pip->allow_deny = *p0;
-	if (*p0 == 'D') {
+	pip->allow_deny = ch;
+	if (ch == 'D') {
	/* Deny:from_IP - prepend */
	pip->next = ip_a_d;
	ip_a_d = pip;
	} else {
-	/* A:from_IP - append (thus D precedes A) */
+	/* A:from_IP - append (thus all D's precedes A's) */
	Htaccess_IP *prev_IP = ip_a_d;
	if (prev_IP == NULL) {
	ip_a_d = pip;
@@ -575,12 +604,12 @@ static void parse_conf(const char *path, int flag)
	}

	#if ENABLE_FEATURE_HTTPD_ERROR_PAGES
-	if (flag == FIRST_PARSE && *p0 == 'E') {
+	if (flag == FIRST_PARSE && ch == 'E') {
	unsigned i;
-	int status = atoi(++p0); /* error status code */
+	int status = atoi(buf + 1); /* error status code */
+
	if (status < HTTP_CONTINUE) {
-	bb_error_msg("config error '%s' in '%s'", buf, filename);
-	continue;
+	goto config_error;
	}
	/* then error page; find matching status */
	for (i = 0; i < ARRAY_SIZE(http_response_type); i++) {
@@ -597,7 +626,7 @@ static void parse_conf(const char *path, int flag)
	#endif

	#if ENABLE_FEATURE_HTTPD_PROXY
-	if (flag == FIRST_PARSE && *p0 == 'P') {
+	if (flag == FIRST_PARSE && ch == 'P') {
	/* P:/url:[http://]hostname[:port]/new/path */
	char url_from, host_port, *url_to;
	Htaccess_Proxy *proxy_entry;
@@ -605,23 +634,20 @@ static void parse_conf(const char *path, int flag)
	url_from = after_colon;
	host_port = strchr(after_colon, ':');
	if (host_port == NULL) {
-	bb_error_msg("config error '%s' in '%s'", buf, filename);
-	continue;
+	goto config_error;
	}
	*host_port++ = '\0';
	if (strncmp(host_port, "http://", 7) == 0)
	host_port += 7;
	if (*host_port == '\0') {
-	bb_error_msg("config error '%s' in '%s'", buf, filename);
-	continue;
+	goto config_error;
	}
	url_to = strchr(host_port, '/');
	if (url_to == NULL) {
-	bb_error_msg("config error '%s' in '%s'", buf, filename);
-	continue;
+	goto config_error;
	}
	*url_to = '\0';
-	proxy_entry = xzalloc(sizeof(Htaccess_Proxy));
+	proxy_entry = xzalloc(sizeof(*proxy_entry));
	proxy_entry->url_from = xstrdup(url_from);
	proxy_entry->host_port = xstrdup(host_port);
	*url_to = '/';
@@ -631,115 +657,87 @@ static void parse_conf(const char *path, int flag)
	continue;
	}
	#endif
+	/* the rest of directives are non-alphabetic,
+	* must avoid using "toupper'ed" ch */
+	ch = buf[0];

-	#if ENABLE_FEATURE_HTTPD_BASIC_AUTH
-	if (*p0 == '/') {
-	/* make full path from httpd root / current_path / config_line_path */
-	const char *tp = (flag == SUBDIR_PARSE ? path : "");
-	p0 = xmalloc(strlen(tp) + (after_colon - buf) + 2 + strlen(after_colon));
-	after_colon[-1] = '\0';
-	sprintf(p0, "/%s%s", tp, buf);
-
-	/* looks like bb_simplify_path... */
-	tp = p = p0;
-	do {
-	if (*p == '/') {
-	if (tp == '/') { / skip duplicate (or initial) slash */
-	continue;
-	}
-	if (*tp == '.') {
-	if (tp[1] == '/' \|\| tp[1] == '\0') { /* remove extra '.' */
-	continue;
-	}
-	if ((tp[1] == '.') && (tp[2] == '/' \|\| tp[2] == '\0')) {
-	++tp;
-	if (p > p0) {
-	while (--p != '/') / omit previous dir */
-	continue;
-	}
-	continue;
-	}
-	}
-	}
-	++p = tp;
-	} while (*++tp);
+	if (ch == '.' /* ".ext:mime/type" */
+	#if ENABLE_FEATURE_HTTPD_CONFIG_WITH_SCRIPT_INTERPR
+	\|\| (ch == '' && buf[1] == '.') / ".php:/path/php" /
+	#endif
+	) {
+	char *p;
+	Htaccess *cur;

-	if ((p == p0) \|\| (p != '/')) { / not a trailing slash */
-	++p; /* so keep last character */
+	cur = xzalloc(sizeof(cur) / includes space for NUL */ + strlen_buf);
+	strcpy(cur->before_colon, buf);
+	p = cur->before_colon + (after_colon - buf);
+	p[-1] = '\0';
+	cur->after_colon = p;
+	if (ch == '.') {
+	/* .mime line: prepend to mime_a list */
+	cur->next = mime_a;
+	mime_a = cur;
+	}
+	#if ENABLE_FEATURE_HTTPD_CONFIG_WITH_SCRIPT_INTERPR
+	else {
+	/* script interpreter line: prepend to script_i list */
+	cur->next = script_i;
+	script_i = cur;
	}
-	*p = ':';
-	strcpy(p + 1, after_colon);
-	}
	#endif
-	if (*p0 == 'I') {
-	index_page = xstrdup(after_colon);
-	continue;
-	}
-
-	/* Do not allow jumping around using H in subdir's configs */
-	if (flag == FIRST_PARSE && *p0 == 'H') {
-	home_httpd = xstrdup(after_colon);
-	xchdir(home_httpd);
	continue;
	}

-	/* storing current config line */
-	cur = xzalloc(sizeof(Htaccess) + strlen(p0));
-	strcpy(cur->before_colon, p0);
	#if ENABLE_FEATURE_HTTPD_BASIC_AUTH
-	if (p0 == '/') / was malloced - see above */
-	free(p0);
-	#endif
-	cur->after_colon = strchr(cur->before_colon, ':');
-	*cur->after_colon++ = '\0';
-	if (cur->before_colon[0] == '.') {
-	/* .mime line: prepend to mime_a list */
-	cur->next = mime_a;
-	mime_a = cur;
-	continue;
-	}
-	#if ENABLE_FEATURE_HTTPD_CONFIG_WITH_SCRIPT_INTERPR
-	if (cur->before_colon[0] == '*' && cur->before_colon[1] == '.') {
-	/* script interpreter line: prepend to script_i list */
-	cur->next = script_i;
-	script_i = cur;
-	continue;
-	}
-	#endif
-	#if ENABLE_FEATURE_HTTPD_BASIC_AUTH
-	//TODO: we do not test for leading "/"??
-	//also, do we leak cur if BASIC_AUTH is off?
-	if (prev == NULL) {
-	/* first line */
-	g_auth = prev = cur;
-	} else {
-	/* sort path, if current length eq or bigger then move up */
-	Htaccess *prev_hti = g_auth;
-	size_t l = strlen(cur->before_colon);
-	Htaccess *hti;
-
-	for (hti = prev_hti; hti; hti = hti->next) {
-	if (l >= strlen(hti->before_colon)) {
-	/* insert before hti */
-	cur->next = hti;
-	if (prev_hti != hti) {
-	prev_hti->next = cur;
-	} else {
-	/* insert as top */
-	g_auth = cur;
+	if (ch == '/') { /* "/file:user:pass" */
+	char *p;
+	Htaccess *cur;
+	unsigned file_len;
+
+	/* note: path is "" unless we are in SUBDIR parse,
+	* otherwise it always starts with "/" */
+	cur = xzalloc(sizeof(cur) / includes space for NUL */
+	+ strlen(path)
+	+ strlen_buf
+	);
+	/* form "/path/file" */
+	sprintf(cur->before_colon, "%s%.*s",
+	path,
+	after_colon - buf - 1, /* includes "/", but not ":" */
+	buf);
+	/* canonicalize it */
+	p = bb_simplify_abs_path_inplace(cur->before_colon);
+	file_len = p - cur->before_colon;
+	/* add "user:pass" after NUL */
+	strcpy(++p, after_colon);
+	cur->after_colon = p;
+
+	/* insert cur into g_auth */
+	/* g_auth is sorted by decreased filename length */
+	{
+	Htaccess auth, *authp;
+
+	authp = &g_auth;
+	while ((auth = *authp) != NULL) {
+	if (file_len >= strlen(auth->before_colon)) {
+	/* insert cur before auth */
+	cur->next = auth;
+	break;
	}
-	break;
+	authp = &auth->next;
	}
-	if (prev_hti != hti)
-	prev_hti = prev_hti->next;
-	}
-	if (!hti) { /* not inserted, add to bottom */
-	prev->next = cur;
-	prev = cur;
+	*authp = cur;
	}
+	continue;
	}
	#endif /* BASIC_AUTH */
+
+	/* the line is not recognized */
+	config_error:
+	bb_error_msg("config error '%s' in '%s'", buf, filename);
	} /* while (fgets) */
+
	fclose(f);
	}

@@ -2031,8 +2029,8 @@ static void handle_incoming_and_exit(const len_and_sockaddr *fromAddr)
	/* We are done reading headers, disable peer timeout */
	alarm(0);

-	if (strcmp(bb_basename(urlcopy), httpd_conf) == 0 \|\| !ip_allowed) {
-	/* protect listing [/path]/httpd_conf or IP deny */
+	if (strcmp(bb_basename(urlcopy), HTTPD_CONF) == 0 \|\| !ip_allowed) {
+	/* protect listing [/path]/httpd.conf or IP deny */
	send_headers_and_exit(HTTP_FORBIDDEN);
	}

@@ -2245,7 +2243,7 @@ static void mini_httpd_inetd(void)

	static void sighup_handler(int sig UNUSED_PARAM)
	{
-	parse_conf(default_path_httpd_conf, SIGNALED_PARSE);
+	parse_conf(DEFAULT_PATH_HTTPD_CONF, SIGNALED_PARSE);
	}

	enum {
@@ -2304,7 +2302,7 @@ int httpd_main(int argc UNUSED_PARAM, char **argv)
	IF_FEATURE_HTTPD_AUTH_MD5("m:")
	IF_FEATURE_HTTPD_SETUID("u:")
	"p:ifv",
-	&configFile, &url_for_decode, &home_httpd
+	&opt_c_configFile, &url_for_decode, &home_httpd
	IF_FEATURE_HTTPD_ENCODE_URL_STR(, &url_for_encode)
	IF_FEATURE_HTTPD_BASIC_AUTH(, &g_realm)
	IF_FEATURE_HTTPD_AUTH_MD5(, &pass)
@@ -2375,7 +2373,7 @@ int httpd_main(int argc UNUSED_PARAM, char **argv)
	}
	#endif

-	parse_conf(default_path_httpd_conf, FIRST_PARSE);
+	parse_conf(DEFAULT_PATH_HTTPD_CONF, FIRST_PARSE);
	if (!(opt & OPT_INETD))
	signal(SIGHUP, sighup_handler);