openwrt/package/iptables/patches/002-layer7_2.22.patch

--- /dev/null
+++ b/extensions/libxt_layer7.c
@@ -0,0 +1,368 @@
+/* 
+   Shared library add-on to iptables for layer 7 matching support. 
+  
+   By Matthew Strait <quadong@users.sf.net>, Oct 2003-Aug 2008.
+
+   http://l7-filter.sf.net 
+
+   This program 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.
+   http://www.gnu.org/licenses/gpl.txt
+*/
+
+#define _GNU_SOURCE
+#include <stdio.h>
+#include <netdb.h>
+#include <string.h>
+#include <stdlib.h>
+#include <getopt.h>
+#include <ctype.h>
+#include <dirent.h>
+
+#include <xtables.h>
+#include <linux/netfilter/xt_layer7.h>
+
+#define MAX_FN_LEN 256
+
+static char l7dir[MAX_FN_LEN] = "\0";
+
+/* Function which prints out usage message. */
+static void help(void)
+{
+	printf(
+	"layer7 match options:\n"
+	"    --l7dir <directory> : Look for patterns here instead of /etc/l7-protocols/\n"
+	"                          (--l7dir must be specified before --l7proto if used)\n"
+	"[!] --l7proto <name>: Match named protocol using /etc/l7-protocols/.../name.pat\n");
+}
+
+static const struct option opts[] = {
+	{ .name = "l7proto", .has_arg = 1, .val = 'p' },
+	{ .name = "l7dir",   .has_arg = 1, .val = 'd' },
+	{ .name = NULL }
+};
+
+/* reads filename, puts protocol info into layer7_protocol_info, number of protocols to numprotos */
+static int parse_protocol_file(char * filename, const char * protoname, struct xt_layer7_info *info)
+{
+	FILE * f;
+	char * line = NULL;
+	size_t len = 0;
+
+	enum { protocol, pattern, done } datatype = protocol;
+
+	f = fopen(filename, "r");
+
+	if(!f)
+		return 0;
+
+	while(getline(&line, &len, f) != -1)
+	{
+		if(strlen(line) < 2 || line[0] == '#')
+			continue;
+
+		/* strip the pesky newline... */
+		if(line[strlen(line) - 1] == '\n')
+			line[strlen(line) - 1] = '\0';
+
+		if(datatype == protocol)
+		{
+			/* Ignore everything on the line beginning with the 
+			first space or tab . For instance, this allows the 
+			protocol line in http.pat to be "http " (or 
+			"http I am so cool") instead of just "http". */
+			if(strchr(line, ' ')){
+				char * space = strchr(line, ' ');
+				space[0] = '\0';
+			}
+			if(strchr(line, '\t')){
+				char * space = strchr(line, '\t');
+				space[0] = '\0';
+			}
+
+			/* sanity check.  First non-comment non-blank 
+			line must be the same as the file name. */
+			if(strcmp(line, protoname))
+				xtables_error(OTHER_PROBLEM, 
+					"Protocol name (%s) doesn't match file name (%s).  Bailing out\n",
+					line, filename);
+
+			if(strlen(line) >= MAX_PROTOCOL_LEN)
+				 xtables_error(PARAMETER_PROBLEM, 
+					"Protocol name in %s too long!", filename);
+			strncpy(info->protocol, line, MAX_PROTOCOL_LEN);
+
+			datatype = pattern; 
+		}
+		else if(datatype == pattern)
+		{
+			if(strlen(line) >= MAX_PATTERN_LEN)
+				 xtables_error(PARAMETER_PROBLEM, "Pattern in %s too long!", filename);
+			strncpy(info->pattern, line, MAX_PATTERN_LEN);
+			
+			datatype = done;			
+			break;
+		}
+		else
+			xtables_error(OTHER_PROBLEM, "Internal error");
+	}
+
+	if(datatype != done)
+		xtables_error(OTHER_PROBLEM, "Failed to get all needed data from %s", filename);
+
+	if(line) free(line);
+	fclose(f);
+
+	return 1;
+}
+
+static int hex2dec(char c)
+{
+        switch (c)
+        {
+                case '0' ... '9':
+                        return c - '0';
+                case 'a' ... 'f':
+                        return c - 'a' + 10;
+                case 'A' ... 'F':
+                        return c - 'A' + 10;
+                default:
+                        xtables_error(OTHER_PROBLEM, "hex2dec: bad value!\n");
+                        return 0;
+        }
+}
+
+/* takes a string with \xHH escapes and returns one with the characters 
+they stand for */
+static char * pre_process(char * s)
+{
+	char * result = malloc(strlen(s) + 1);
+	int sindex = 0, rrindex = 0;
+        while( sindex < strlen(s) )
+        {
+            if( sindex + 3 < strlen(s) &&
+                s[sindex] == '\\' && s[sindex+1] == 'x' && 
+                isxdigit(s[sindex + 2]) && isxdigit(s[sindex + 3]) ) 
+                {
+                        /* carefully remember to call tolower here... */
+                        result[rrindex] = tolower( hex2dec(s[sindex + 2])*16 +
+                                                  hex2dec(s[sindex + 3] ) );
+
+			switch ( result[rrindex] )
+			{
+			case 0x24:
+			case 0x28:
+			case 0x29:
+			case 0x2a:
+			case 0x2b:
+			case 0x2e:
+			case 0x3f:
+			case 0x5b:
+			case 0x5c:
+			case 0x5d:
+			case 0x5e:
+			case 0x7c:
+				fprintf(stderr, 
+					"Warning: layer7 regexp contains a control character, %c, in hex (\\x%c%c).\n"
+					"I recommend that you write this as %c or \\%c, depending on what you meant.\n",
+					result[rrindex], s[sindex + 2], s[sindex + 3], result[rrindex], result[rrindex]);
+				break;
+			case 0x00:
+				fprintf(stderr, 
+					"Warning: null (\\x00) in layer7 regexp.  A null terminates the regexp string!\n");
+				break;
+			default:
+				break;
+			}
+
+
+                        sindex += 3; /* 4 total */
+                }
+                else
+                        result[rrindex] = tolower(s[sindex]);
+
+		sindex++; 
+		rrindex++;
+        }
+	result[rrindex] = '\0';
+
+	return result;
+}
+
+#define MAX_SUBDIRS 128
+static char ** readl7dir(char * dirname)
+{
+        DIR             * scratchdir;
+        struct dirent   ** namelist;
+	char ** subdirs = malloc(MAX_SUBDIRS * sizeof(char *));
+
+        int n, d = 1;
+	subdirs[0] = "";
+
+        n = scandir(dirname, &namelist, 0, alphasort);
+
+	if (n < 0)
+	{
+            perror("scandir");
+	    xtables_error(OTHER_PROBLEM, "Couldn't open %s\n", dirname);
+	}
+        else 
+	{
+            	while(n--) 
+		{
+			char fulldirname[MAX_FN_LEN];
+
+			snprintf(fulldirname, MAX_FN_LEN, "%s/%s", dirname, namelist[n]->d_name);
+
+                	if((scratchdir = opendir(fulldirname)) != NULL)
+			{
+				closedir(scratchdir);
+
+				if(!strcmp(namelist[n]->d_name, ".") || 
+				   !strcmp(namelist[n]->d_name, ".."))
+					/* do nothing */ ;
+				else
+				{
+					subdirs[d] = malloc(strlen(namelist[n]->d_name) + 1);
+					strcpy(subdirs[d], namelist[n]->d_name);
+					d++;
+					if(d >= MAX_SUBDIRS - 1)
+					{
+						fprintf(stderr, 
+						  "Too many subdirectories, skipping the rest!\n");
+						break;
+					}
+				}
+			}
+                	free(namelist[n]);
+            	}
+            	free(namelist);
+        }
+	
+	subdirs[d] = NULL;
+
+	return subdirs;
+}
+
+static void parse_layer7_protocol(const char *s, struct xt_layer7_info *info)
+{
+	char filename[MAX_FN_LEN];
+	char * dir = NULL;
+	char ** subdirs;
+	int n = 0, done = 0;
+
+	if(strlen(l7dir) > 0) dir = l7dir;
+	else                  dir = "/etc/l7-protocols";
+
+	subdirs = readl7dir(dir);
+
+	while(subdirs[n] != NULL)
+	{
+		int c = snprintf(filename, MAX_FN_LEN, "%s/%s/%s.pat", dir, subdirs[n], s);
+
+		if(c > MAX_FN_LEN)
+			xtables_error(OTHER_PROBLEM, 
+				"Filename beginning with %s is too long!\n", filename);
+
+		/* read in the pattern from the file */
+		if(parse_protocol_file(filename, s, info)){
+			done = 1;
+			break;
+		}
+		
+		n++;
+	}
+
+	if(!done)
+		xtables_error(OTHER_PROBLEM, 
+			"Couldn't find a pattern definition file for %s.\n", s);
+
+	/* process \xHH escapes and tolower everything. (our regex lib has no
+	case insensitivity option.) */
+	strncpy(info->pattern, pre_process(info->pattern), MAX_PATTERN_LEN);
+}
+
+/* Function which parses command options; returns true if it ate an option */
+static int parse(int c, char **argv, int invert, unsigned int *flags,
+      const void *entry, struct xt_entry_match **match)
+{
+	struct xt_layer7_info *layer7info = 
+		(struct xt_layer7_info *)(*match)->data;
+
+	switch (c) {
+	case 'p':
+		parse_layer7_protocol(argv[optind-1], layer7info);
+		if (invert)
+			layer7info->invert = true;
+		*flags = 1;
+		break;
+
+	case 'd':
+		if(strlen(argv[optind-1]) >= MAX_FN_LEN)
+			xtables_error(PARAMETER_PROBLEM, "directory name too long\n");
+
+		strncpy(l7dir, argv[optind-1], MAX_FN_LEN);
+
+		*flags = 1;
+		break;
+
+	default:
+		return 0;
+	}
+
+	return 1;
+}
+
+/* Final check; must have specified --l7proto */
+static void final_check(unsigned int flags)
+{
+	if (!flags)
+		xtables_error(PARAMETER_PROBLEM,
+			   "LAYER7 match: You must specify `--l7proto'");
+}
+
+static void print_protocol(char s[], int invert, int numeric)
+{
+	fputs("l7proto ", stdout);
+	if (invert) fputc('!', stdout);
+	printf("%s ", s);
+}
+
+/* Prints out the matchinfo. */
+static void print(const void *ip,
+      const struct xt_entry_match *match,
+      int numeric)
+{
+	printf("LAYER7 ");
+	print_protocol(((struct xt_layer7_info *)match->data)->protocol,
+		  ((struct xt_layer7_info *)match->data)->invert, numeric);
+}
+/* Saves the union ipt_matchinfo in parsable form to stdout. */
+static void save(const void *ip, const struct xt_entry_match *match)
+{
+        const struct xt_layer7_info *info =
+            (const struct xt_layer7_info*) match->data;
+
+        printf("--l7proto %s%s ", (info->invert)? "! ":"", info->protocol);
+}
+
+static struct xtables_match layer7 = { 
+    .family        = AF_INET,
+    .name          = "layer7",
+    .version       = XTABLES_VERSION,
+    .size          = XT_ALIGN(sizeof(struct xt_layer7_info)),
+    .userspacesize = XT_ALIGN(sizeof(struct xt_layer7_info)),
+    .help          = &help,
+    .parse         = &parse,
+    .final_check   = &final_check,
+    .print         = &print,
+    .save          = &save,
+    .extra_opts    = opts
+};
+
+void _init(void)
+{
+	xtables_register_match(&layer7);
+}