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[openwrt.git] / target / linux / linux-2.6 / patches / generic / 100-netfilter_layer7.patch
1 --- linux-2.6.14/include/linux/netfilter_ipv4/ip_conntrack.h 2005-10-27 19:02:08.000000000 -0500
2 +++ linux-2.6.14-layer7/include/linux/netfilter_ipv4/ip_conntrack.h 2005-11-12 17:31:34.000000000 -0600
3 @@ -253,6 +253,15 @@ struct ip_conntrack
4 /* Traversed often, so hopefully in different cacheline to top */
5 /* These are my tuples; original and reply */
6 struct ip_conntrack_tuple_hash tuplehash[IP_CT_DIR_MAX];
7 +
8 +#if defined(CONFIG_IP_NF_MATCH_LAYER7) || defined(CONFIG_IP_NF_MATCH_LAYER7_MODULE)
9 + struct {
10 + char * app_proto; /* e.g. "http". NULL before decision. "unknown" after decision if no match */
11 + char * app_data; /* application layer data so far. NULL after match decision */
12 + unsigned int app_data_len;
13 + } layer7;
14 +#endif
15 +
16 };
17
18 struct ip_conntrack_expect
19 --- linux-2.6.14/include/linux/netfilter_ipv4/ipt_layer7.h 1969-12-31 18:00:00.000000000 -0600
20 +++ linux-2.6.14-layer7/include/linux/netfilter_ipv4/ipt_layer7.h 2005-11-12 17:31:34.000000000 -0600
21 @@ -0,0 +1,26 @@
22 +/*
23 + By Matthew Strait <quadong@users.sf.net>, Dec 2003.
24 + http://l7-filter.sf.net
25 +
26 + This program is free software; you can redistribute it and/or
27 + modify it under the terms of the GNU General Public License
28 + as published by the Free Software Foundation; either version
29 + 2 of the License, or (at your option) any later version.
30 + http://www.gnu.org/licenses/gpl.txt
31 +*/
32 +
33 +#ifndef _IPT_LAYER7_H
34 +#define _IPT_LAYER7_H
35 +
36 +#define MAX_PATTERN_LEN 8192
37 +#define MAX_PROTOCOL_LEN 256
38 +
39 +typedef char *(*proc_ipt_search) (char *, char, char *);
40 +
41 +struct ipt_layer7_info {
42 + char protocol[MAX_PROTOCOL_LEN];
43 + char invert:1;
44 + char pattern[MAX_PATTERN_LEN];
45 +};
46 +
47 +#endif /* _IPT_LAYER7_H */
48 --- linux-2.6.14/net/ipv4/netfilter/Kconfig 2005-10-27 19:02:08.000000000 -0500
49 +++ linux-2.6.14-layer7/net/ipv4/netfilter/Kconfig 2005-11-12 17:31:34.000000000 -0600
50 @@ -205,6 +205,24 @@ config IP_NF_MATCH_MAC
51
52 To compile it as a module, choose M here. If unsure, say N.
53
54 +config IP_NF_MATCH_LAYER7
55 + tristate "Layer 7 match support (EXPERIMENTAL)"
56 + depends on IP_NF_IPTABLES && IP_NF_CT_ACCT && IP_NF_CONNTRACK && EXPERIMENTAL
57 + help
58 + Say Y if you want to be able to classify connections (and their
59 + packets) based on regular expression matching of their application
60 + layer data. This is one way to classify applications such as
61 + peer-to-peer filesharing systems that do not always use the same
62 + port.
63 +
64 + To compile it as a module, choose M here. If unsure, say N.
65 +
66 +config IP_NF_MATCH_LAYER7_DEBUG
67 + bool "Layer 7 debugging output"
68 + depends on IP_NF_MATCH_LAYER7
69 + help
70 + Say Y to get lots of debugging output.
71 +
72 config IP_NF_MATCH_PKTTYPE
73 tristate "Packet type match support"
74 depends on IP_NF_IPTABLES
75 --- linux-2.6.14/net/ipv4/netfilter/Makefile 2005-10-27 19:02:08.000000000 -0500
76 +++ linux-2.6.14-layer7/net/ipv4/netfilter/Makefile 2005-11-12 17:31:34.000000000 -0600
77 @@ -74,6 +74,8 @@ obj-$(CONFIG_IP_NF_MATCH_PHYSDEV) += ipt
78 obj-$(CONFIG_IP_NF_MATCH_COMMENT) += ipt_comment.o
79 obj-$(CONFIG_IP_NF_MATCH_STRING) += ipt_string.o
80
81 +obj-$(CONFIG_IP_NF_MATCH_LAYER7) += ipt_layer7.o
82 +
83 # targets
84 obj-$(CONFIG_IP_NF_TARGET_REJECT) += ipt_REJECT.o
85 obj-$(CONFIG_IP_NF_TARGET_TOS) += ipt_TOS.o
86 --- linux-2.6.14/net/ipv4/netfilter/ip_conntrack_core.c 2005-10-27 19:02:08.000000000 -0500
87 +++ linux-2.6.14-layer7/net/ipv4/netfilter/ip_conntrack_core.c 2005-11-12 17:31:34.000000000 -0600
88 @@ -335,6 +335,13 @@ destroy_conntrack(struct nf_conntrack *n
89 * too. */
90 ip_ct_remove_expectations(ct);
91
92 + #if defined(CONFIG_IP_NF_MATCH_LAYER7) || defined(CONFIG_IP_NF_MATCH_LAYER7_MODULE)
93 + if(ct->layer7.app_proto)
94 + kfree(ct->layer7.app_proto);
95 + if(ct->layer7.app_data)
96 + kfree(ct->layer7.app_data);
97 + #endif
98 +
99 /* We overload first tuple to link into unconfirmed list. */
100 if (!is_confirmed(ct)) {
101 BUG_ON(list_empty(&ct->tuplehash[IP_CT_DIR_ORIGINAL].list));
102 --- linux-2.6.14/net/ipv4/netfilter/ip_conntrack_standalone.c 2005-10-27 19:02:08.000000000 -0500
103 +++ linux-2.6.14-layer7/net/ipv4/netfilter/ip_conntrack_standalone.c 2005-11-12 17:31:34.000000000 -0600
104 @@ -188,6 +188,12 @@ static int ct_seq_show(struct seq_file *
105 return -ENOSPC;
106 #endif
107
108 +#if defined(CONFIG_IP_NF_MATCH_LAYER7) || defined(CONFIG_IP_NF_MATCH_LAYER7_MODULE)
109 + if(conntrack->layer7.app_proto)
110 + if (seq_printf(s, "l7proto=%s ",conntrack->layer7.app_proto))
111 + return 1;
112 +#endif
113 +
114 if (seq_printf(s, "use=%u\n", atomic_read(&conntrack->ct_general.use)))
115 return -ENOSPC;
116
117 --- linux-2.6.14/net/ipv4/netfilter/ipt_layer7.c 1969-12-31 18:00:00.000000000 -0600
118 +++ linux-2.6.14-layer7/net/ipv4/netfilter/ipt_layer7.c 2005-11-12 17:49:24.000000000 -0600
119 @@ -0,0 +1,569 @@
120 +/*
121 + Kernel module to match application layer (OSI layer 7)
122 + data in connections.
123 +
124 + http://l7-filter.sf.net
125 +
126 + By Matthew Strait and Ethan Sommer, 2003-2005.
127 +
128 + This program is free software; you can redistribute it and/or
129 + modify it under the terms of the GNU General Public License
130 + as published by the Free Software Foundation; either version
131 + 2 of the License, or (at your option) any later version.
132 + http://www.gnu.org/licenses/gpl.txt
133 +
134 + Based on ipt_string.c (C) 2000 Emmanuel Roger <winfield@freegates.be>
135 + and cls_layer7.c (C) 2003 Matthew Strait, Ethan Sommer, Justin Levandoski
136 +*/
137 +
138 +#include <linux/module.h>
139 +#include <linux/skbuff.h>
140 +#include <linux/netfilter_ipv4/ip_conntrack.h>
141 +#include <linux/proc_fs.h>
142 +#include <linux/ctype.h>
143 +#include <net/ip.h>
144 +#include <net/tcp.h>
145 +#include <linux/spinlock.h>
146 +
147 +#include "regexp/regexp.c"
148 +
149 +#include <linux/netfilter_ipv4/ipt_layer7.h>
150 +#include <linux/netfilter_ipv4/ip_tables.h>
151 +
152 +MODULE_AUTHOR("Matthew Strait <quadong@users.sf.net>, Ethan Sommer <sommere@users.sf.net>");
153 +MODULE_LICENSE("GPL");
154 +MODULE_DESCRIPTION("iptables application layer match module");
155 +MODULE_VERSION("2.0");
156 +
157 +static int maxdatalen = 2048; // this is the default
158 +module_param(maxdatalen, int, 0444);
159 +MODULE_PARM_DESC(maxdatalen, "maximum bytes of data looked at by l7-filter");
160 +
161 +#ifdef CONFIG_IP_NF_MATCH_LAYER7_DEBUG
162 + #define DPRINTK(format,args...) printk(format,##args)
163 +#else
164 + #define DPRINTK(format,args...)
165 +#endif
166 +
167 +#define TOTAL_PACKETS master_conntrack->counters[IP_CT_DIR_ORIGINAL].packets + \
168 + master_conntrack->counters[IP_CT_DIR_REPLY].packets
169 +
170 +/* Number of packets whose data we look at.
171 +This can be modified through /proc/net/layer7_numpackets */
172 +static int num_packets = 10;
173 +
174 +static struct pattern_cache {
175 + char * regex_string;
176 + regexp * pattern;
177 + struct pattern_cache * next;
178 +} * first_pattern_cache = NULL;
179 +
180 +/* I'm new to locking. Here are my assumptions:
181 +
182 +- No one will write to /proc/net/layer7_numpackets over and over very fast;
183 + if they did, nothing awful would happen.
184 +
185 +- This code will never be processing the same packet twice at the same time,
186 + because iptables rules are traversed in order.
187 +
188 +- It doesn't matter if two packets from different connections are in here at
189 + the same time, because they don't share any data.
190 +
191 +- It _does_ matter if two packets from the same connection are here at the same
192 + time. In this case, we have to protect the conntracks and the list of
193 + compiled patterns.
194 +*/
195 +DEFINE_RWLOCK(ct_lock);
196 +DEFINE_SPINLOCK(list_lock);
197 +
198 +#ifdef CONFIG_IP_NF_MATCH_LAYER7_DEBUG
199 +/* Converts an unfriendly string into a friendly one by
200 +replacing unprintables with periods and all whitespace with " ". */
201 +static char * friendly_print(unsigned char * s)
202 +{
203 + char * f = kmalloc(strlen(s) + 1, GFP_ATOMIC);
204 + int i;
205 +
206 + if(!f) {
207 + if (net_ratelimit())
208 + printk(KERN_ERR "layer7: out of memory in friendly_print, bailing.\n");
209 + return NULL;
210 + }
211 +
212 + for(i = 0; i < strlen(s); i++){
213 + if(isprint(s[i]) && s[i] < 128) f[i] = s[i];
214 + else if(isspace(s[i])) f[i] = ' ';
215 + else f[i] = '.';
216 + }
217 + f[i] = '\0';
218 + return f;
219 +}
220 +
221 +static char dec2hex(int i)
222 +{
223 + switch (i) {
224 + case 0 ... 9:
225 + return (char)(i + '0');
226 + break;
227 + case 10 ... 15:
228 + return (char)(i - 10 + 'a');
229 + break;
230 + default:
231 + if (net_ratelimit())
232 + printk("Problem in dec2hex\n");
233 + return '\0';
234 + }
235 +}
236 +
237 +static char * hex_print(unsigned char * s)
238 +{
239 + char * g = kmalloc(strlen(s)*3 + 1, GFP_ATOMIC);
240 + int i;
241 +
242 + if(!g) {
243 + if (net_ratelimit())
244 + printk(KERN_ERR "layer7: out of memory in hex_print, bailing.\n");
245 + return NULL;
246 + }
247 +
248 + for(i = 0; i < strlen(s); i++) {
249 + g[i*3 ] = dec2hex(s[i]/16);
250 + g[i*3 + 1] = dec2hex(s[i]%16);
251 + g[i*3 + 2] = ' ';
252 + }
253 + g[i*3] = '\0';
254 +
255 + return g;
256 +}
257 +#endif // DEBUG
258 +
259 +/* Use instead of regcomp. As we expect to be seeing the same regexps over and
260 +over again, it make sense to cache the results. */
261 +static regexp * compile_and_cache(char * regex_string, char * protocol)
262 +{
263 + struct pattern_cache * node = first_pattern_cache;
264 + struct pattern_cache * last_pattern_cache = first_pattern_cache;
265 + struct pattern_cache * tmp;
266 + unsigned int len;
267 +
268 + while (node != NULL) {
269 + if (!strcmp(node->regex_string, regex_string))
270 + return node->pattern;
271 +
272 + last_pattern_cache = node;/* points at the last non-NULL node */
273 + node = node->next;
274 + }
275 +
276 + /* If we reach the end of the list, then we have not yet cached
277 + the pattern for this regex. Let's do that now.
278 + Be paranoid about running out of memory to avoid list corruption. */
279 + tmp = kmalloc(sizeof(struct pattern_cache), GFP_ATOMIC);
280 +
281 + if(!tmp) {
282 + if (net_ratelimit())
283 + printk(KERN_ERR "layer7: out of memory in compile_and_cache, bailing.\n");
284 + return NULL;
285 + }
286 +
287 + tmp->regex_string = kmalloc(strlen(regex_string) + 1, GFP_ATOMIC);
288 + tmp->pattern = kmalloc(sizeof(struct regexp), GFP_ATOMIC);
289 + tmp->next = NULL;
290 +
291 + if(!tmp->regex_string || !tmp->pattern) {
292 + if (net_ratelimit())
293 + printk(KERN_ERR "layer7: out of memory in compile_and_cache, bailing.\n");
294 + kfree(tmp->regex_string);
295 + kfree(tmp->pattern);
296 + kfree(tmp);
297 + return NULL;
298 + }
299 +
300 + /* Ok. The new node is all ready now. */
301 + node = tmp;
302 +
303 + if(first_pattern_cache == NULL) /* list is empty */
304 + first_pattern_cache = node; /* make node the beginning */
305 + else
306 + last_pattern_cache->next = node; /* attach node to the end */
307 +
308 + /* copy the string and compile the regex */
309 + len = strlen(regex_string);
310 + DPRINTK("About to compile this: \"%s\"\n", regex_string);
311 + node->pattern = regcomp(regex_string, &len);
312 + if ( !node->pattern ) {
313 + if (net_ratelimit())
314 + printk(KERN_ERR "layer7: Error compiling regexp \"%s\" (%s)\n", regex_string, protocol);
315 + /* pattern is now cached as NULL, so we won't try again. */
316 + }
317 +
318 + strcpy(node->regex_string, regex_string);
319 + return node->pattern;
320 +}
321 +
322 +static int can_handle(const struct sk_buff *skb)
323 +{
324 + if(!skb->nh.iph) /* not IP */
325 + return 0;
326 + if(skb->nh.iph->protocol != IPPROTO_TCP &&
327 + skb->nh.iph->protocol != IPPROTO_UDP &&
328 + skb->nh.iph->protocol != IPPROTO_ICMP)
329 + return 0;
330 + return 1;
331 +}
332 +
333 +/* Returns offset the into the skb->data that the application data starts */
334 +static int app_data_offset(const struct sk_buff *skb)
335 +{
336 + /* In case we are ported somewhere (ebtables?) where skb->nh.iph
337 + isn't set, this can be gotten from 4*(skb->data[0] & 0x0f) as well. */
338 + int ip_hl = 4*skb->nh.iph->ihl;
339 +
340 + if( skb->nh.iph->protocol == IPPROTO_TCP ) {
341 + /* 12 == offset into TCP header for the header length field.
342 + Can't get this with skb->h.th->doff because the tcphdr
343 + struct doesn't get set when routing (this is confirmed to be
344 + true in Netfilter as well as QoS.) */
345 + int tcp_hl = 4*(skb->data[ip_hl + 12] >> 4);
346 +
347 + return ip_hl + tcp_hl;
348 + } else if( skb->nh.iph->protocol == IPPROTO_UDP ) {
349 + return ip_hl + 8; /* UDP header is always 8 bytes */
350 + } else if( skb->nh.iph->protocol == IPPROTO_ICMP ) {
351 + return ip_hl + 8; /* ICMP header is 8 bytes */
352 + } else {
353 + if (net_ratelimit())
354 + printk(KERN_ERR "layer7: tried to handle unknown protocol!\n");
355 + return ip_hl + 8; /* something reasonable */
356 + }
357 +}
358 +
359 +/* handles whether there's a match when we aren't appending data anymore */
360 +static int match_no_append(struct ip_conntrack * conntrack, struct ip_conntrack * master_conntrack,
361 + enum ip_conntrack_info ctinfo, enum ip_conntrack_info master_ctinfo,
362 + struct ipt_layer7_info * info)
363 +{
364 + /* If we're in here, throw the app data away */
365 + write_lock(&ct_lock);
366 + if(master_conntrack->layer7.app_data != NULL) {
367 +
368 + #ifdef CONFIG_IP_NF_MATCH_LAYER7_DEBUG
369 + if(!master_conntrack->layer7.app_proto) {
370 + char * f = friendly_print(master_conntrack->layer7.app_data);
371 + char * g = hex_print(master_conntrack->layer7.app_data);
372 + DPRINTK("\nl7-filter gave up after %d bytes (%llu packets):\n%s\n",
373 + strlen(f),
374 + TOTAL_PACKETS, f);
375 + kfree(f);
376 + DPRINTK("In hex: %s\n", g);
377 + kfree(g);
378 + }
379 + #endif
380 +
381 + kfree(master_conntrack->layer7.app_data);
382 + master_conntrack->layer7.app_data = NULL; /* don't free again */
383 + }
384 + write_unlock(&ct_lock);
385 +
386 + if(master_conntrack->layer7.app_proto){
387 + /* Here child connections set their .app_proto (for /proc/net/ip_conntrack) */
388 + write_lock(&ct_lock);
389 + if(!conntrack->layer7.app_proto) {
390 + conntrack->layer7.app_proto = kmalloc(strlen(master_conntrack->layer7.app_proto)+1, GFP_ATOMIC);
391 + if(!conntrack->layer7.app_proto){
392 + if (net_ratelimit())
393 + printk(KERN_ERR "layer7: out of memory in match_no_append, bailing.\n");
394 + write_unlock(&ct_lock);
395 + return 1;
396 + }
397 + strcpy(conntrack->layer7.app_proto, master_conntrack->layer7.app_proto);
398 + }
399 + write_unlock(&ct_lock);
400 +
401 + return (!strcmp(master_conntrack->layer7.app_proto, info->protocol));
402 + }
403 + else {
404 + /* If not classified, set to "unknown" to distinguish from
405 + connections that are still being tested. */
406 + write_lock(&ct_lock);
407 + master_conntrack->layer7.app_proto = kmalloc(strlen("unknown")+1, GFP_ATOMIC);
408 + if(!master_conntrack->layer7.app_proto){
409 + if (net_ratelimit())
410 + printk(KERN_ERR "layer7: out of memory in match_no_append, bailing.\n");
411 + write_unlock(&ct_lock);
412 + return 1;
413 + }
414 + strcpy(master_conntrack->layer7.app_proto, "unknown");
415 + write_unlock(&ct_lock);
416 + return 0;
417 + }
418 +}
419 +
420 +/* add the new app data to the conntrack. Return number of bytes added. */
421 +static int add_data(struct ip_conntrack * master_conntrack,
422 + char * app_data, int appdatalen)
423 +{
424 + int length = 0, i;
425 + int oldlength = master_conntrack->layer7.app_data_len;
426 +
427 + /* Strip nulls. Make everything lower case (our regex lib doesn't
428 + do case insensitivity). Add it to the end of the current data. */
429 + for(i = 0; i < maxdatalen-oldlength-1 &&
430 + i < appdatalen; i++) {
431 + if(app_data[i] != '\0') {
432 + master_conntrack->layer7.app_data[length+oldlength] =
433 + /* the kernel version of tolower mungs 'upper ascii' */
434 + isascii(app_data[i])? tolower(app_data[i]) : app_data[i];
435 + length++;
436 + }
437 + }
438 +
439 + master_conntrack->layer7.app_data[length+oldlength] = '\0';
440 + master_conntrack->layer7.app_data_len = length + oldlength;
441 +
442 + return length;
443 +}
444 +
445 +/* Returns true on match and false otherwise. */
446 +static int match(/* const */struct sk_buff *skb, const struct net_device *in,
447 + const struct net_device *out, const void *matchinfo,
448 + int offset, int *hotdrop)
449 +{
450 + struct ipt_layer7_info * info = (struct ipt_layer7_info *)matchinfo;
451 + enum ip_conntrack_info master_ctinfo, ctinfo;
452 + struct ip_conntrack *master_conntrack, *conntrack;
453 + unsigned char * app_data;
454 + unsigned int pattern_result, appdatalen;
455 + regexp * comppattern;
456 +
457 + if(!can_handle(skb)){
458 + DPRINTK("layer7: This is some protocol I can't handle.\n");
459 + return info->invert;
460 + }
461 +
462 + /* Treat parent & all its children together as one connection, except
463 + for the purpose of setting conntrack->layer7.app_proto in the actual
464 + connection. This makes /proc/net/ip_conntrack more satisfying. */
465 + if(!(conntrack = ip_conntrack_get((struct sk_buff *)skb, &ctinfo)) ||
466 + !(master_conntrack = ip_conntrack_get((struct sk_buff *)skb, &master_ctinfo))) {
467 + //DPRINTK("layer7: packet is not from a known connection, giving up.\n");
468 + return info->invert;
469 + }
470 +
471 + /* Try to get a master conntrack (and its master etc) for FTP, etc. */
472 + while (master_ct(master_conntrack) != NULL)
473 + master_conntrack = master_ct(master_conntrack);
474 +
475 + /* if we've classified it or seen too many packets */
476 + if(TOTAL_PACKETS > num_packets ||
477 + master_conntrack->layer7.app_proto) {
478 +
479 + pattern_result = match_no_append(conntrack, master_conntrack, ctinfo, master_ctinfo, info);
480 +
481 + /* skb->cb[0] == seen. Avoid doing things twice if there are two l7
482 + rules. I'm not sure that using cb for this purpose is correct, although
483 + it says "put your private variables there". But it doesn't look like it
484 + is being used for anything else in the skbs that make it here. How can
485 + I write to cb without making the compiler angry? */
486 + skb->cb[0] = 1; /* marking it seen here is probably irrelevant, but consistant */
487 +
488 + return (pattern_result ^ info->invert);
489 + }
490 +
491 + if(skb_is_nonlinear(skb)){
492 + if(skb_linearize(skb, GFP_ATOMIC) != 0){
493 + if (net_ratelimit())
494 + printk(KERN_ERR "layer7: failed to linearize packet, bailing.\n");
495 + return info->invert;
496 + }
497 + }
498 +
499 + /* now that the skb is linearized, it's safe to set these. */
500 + app_data = skb->data + app_data_offset(skb);
501 + appdatalen = skb->tail - app_data;
502 +
503 + spin_lock_bh(&list_lock);
504 + /* the return value gets checked later, when we're ready to use it */
505 + comppattern = compile_and_cache(info->pattern, info->protocol);
506 + spin_unlock_bh(&list_lock);
507 +
508 + /* On the first packet of a connection, allocate space for app data */
509 + write_lock(&ct_lock);
510 + if(TOTAL_PACKETS == 1 && !skb->cb[0] && !master_conntrack->layer7.app_data) {
511 + master_conntrack->layer7.app_data = kmalloc(maxdatalen, GFP_ATOMIC);
512 + if(!master_conntrack->layer7.app_data){
513 + if (net_ratelimit())
514 + printk(KERN_ERR "layer7: out of memory in match, bailing.\n");
515 + write_unlock(&ct_lock);
516 + return info->invert;
517 + }
518 +
519 + master_conntrack->layer7.app_data[0] = '\0';
520 + }
521 + write_unlock(&ct_lock);
522 +
523 + /* Can be here, but unallocated, if numpackets is increased near
524 + the beginning of a connection */
525 + if(master_conntrack->layer7.app_data == NULL)
526 + return (info->invert); /* unmatched */
527 +
528 + if(!skb->cb[0]){
529 + int newbytes;
530 + write_lock(&ct_lock);
531 + newbytes = add_data(master_conntrack, app_data, appdatalen);
532 + write_unlock(&ct_lock);
533 +
534 + if(newbytes == 0) { /* didn't add any data */
535 + skb->cb[0] = 1;
536 + /* Didn't match before, not going to match now */
537 + return info->invert;
538 + }
539 + }
540 +
541 + /* If looking for "unknown", then never match. "Unknown" means that
542 + we've given up; we're still trying with these packets. */
543 + if(!strcmp(info->protocol, "unknown")) {
544 + pattern_result = 0;
545 + /* If the regexp failed to compile, don't bother running it */
546 + } else if(comppattern && regexec(comppattern, master_conntrack->layer7.app_data)) {
547 + DPRINTK("layer7: matched %s\n", info->protocol);
548 + pattern_result = 1;
549 + } else pattern_result = 0;
550 +
551 + if(pattern_result) {
552 + write_lock(&ct_lock);
553 + master_conntrack->layer7.app_proto = kmalloc(strlen(info->protocol)+1, GFP_ATOMIC);
554 + if(!master_conntrack->layer7.app_proto){
555 + if (net_ratelimit())
556 + printk(KERN_ERR "layer7: out of memory in match, bailing.\n");
557 + write_unlock(&ct_lock);
558 + return (pattern_result ^ info->invert);
559 + }
560 + strcpy(master_conntrack->layer7.app_proto, info->protocol);
561 + write_unlock(&ct_lock);
562 + }
563 +
564 + /* mark the packet seen */
565 + skb->cb[0] = 1;
566 +
567 + return (pattern_result ^ info->invert);
568 +}
569 +
570 +static int checkentry(const char *tablename, const struct ipt_ip *ip,
571 + void *matchinfo, unsigned int matchsize, unsigned int hook_mask)
572 +{
573 + if (matchsize != IPT_ALIGN(sizeof(struct ipt_layer7_info)))
574 + return 0;
575 + return 1;
576 +}
577 +
578 +static struct ipt_match layer7_match = {
579 + .name = "layer7",
580 + .match = &match,
581 + .checkentry = &checkentry,
582 + .me = THIS_MODULE
583 +};
584 +
585 +/* taken from drivers/video/modedb.c */
586 +static int my_atoi(const char *s)
587 +{
588 + int val = 0;
589 +
590 + for (;; s++) {
591 + switch (*s) {
592 + case '0'...'9':
593 + val = 10*val+(*s-'0');
594 + break;
595 + default:
596 + return val;
597 + }
598 + }
599 +}
600 +
601 +/* write out num_packets to userland. */
602 +static int layer7_read_proc(char* page, char ** start, off_t off, int count,
603 + int* eof, void * data)
604 +{
605 + if(num_packets > 99 && net_ratelimit())
606 + printk(KERN_ERR "layer7: NOT REACHED. num_packets too big\n");
607 +
608 + page[0] = num_packets/10 + '0';
609 + page[1] = num_packets%10 + '0';
610 + page[2] = '\n';
611 + page[3] = '\0';
612 +
613 + *eof=1;
614 +
615 + return 3;
616 +}
617 +
618 +/* Read in num_packets from userland */
619 +static int layer7_write_proc(struct file* file, const char* buffer,
620 + unsigned long count, void *data)
621 +{
622 + char * foo = kmalloc(count, GFP_ATOMIC);
623 +
624 + if(!foo){
625 + if (net_ratelimit())
626 + printk(KERN_ERR "layer7: out of memory, bailing. num_packets unchanged.\n");
627 + return count;
628 + }
629 +
630 + if(copy_from_user(foo, buffer, count)) {
631 + return -EFAULT;
632 + }
633 +
634 +
635 + num_packets = my_atoi(foo);
636 + kfree (foo);
637 +
638 + /* This has an arbitrary limit to make the math easier. I'm lazy.
639 + But anyway, 99 is a LOT! If you want more, you're doing it wrong! */
640 + if(num_packets > 99) {
641 + printk(KERN_WARNING "layer7: num_packets can't be > 99.\n");
642 + num_packets = 99;
643 + } else if(num_packets < 1) {
644 + printk(KERN_WARNING "layer7: num_packets can't be < 1.\n");
645 + num_packets = 1;
646 + }
647 +
648 + return count;
649 +}
650 +
651 +/* register the proc file */
652 +static void layer7_init_proc(void)
653 +{
654 + struct proc_dir_entry* entry;
655 + entry = create_proc_entry("layer7_numpackets", 0644, proc_net);
656 + entry->read_proc = layer7_read_proc;
657 + entry->write_proc = layer7_write_proc;
658 +}
659 +
660 +static void layer7_cleanup_proc(void)
661 +{
662 + remove_proc_entry("layer7_numpackets", proc_net);
663 +}
664 +
665 +static int __init init(void)
666 +{
667 + layer7_init_proc();
668 + if(maxdatalen < 1) {
669 + printk(KERN_WARNING "layer7: maxdatalen can't be < 1, using 1\n");
670 + maxdatalen = 1;
671 + }
672 + /* This is not a hard limit. It's just here to prevent people from
673 + bringing their slow machines to a grinding halt. */
674 + else if(maxdatalen > 65536) {
675 + printk(KERN_WARNING "layer7: maxdatalen can't be > 65536, using 65536\n");
676 + maxdatalen = 65536;
677 + }
678 + return ipt_register_match(&layer7_match);
679 +}
680 +
681 +static void __exit fini(void)
682 +{
683 + layer7_cleanup_proc();
684 + ipt_unregister_match(&layer7_match);
685 +}
686 +
687 +module_init(init);
688 +module_exit(fini);
689 --- linux-2.6.14/net/ipv4/netfilter/regexp/regexp.c 1969-12-31 18:00:00.000000000 -0600
690 +++ linux-2.6.14-layer7/net/ipv4/netfilter/regexp/regexp.c 2005-11-12 17:31:34.000000000 -0600
691 @@ -0,0 +1,1195 @@
692 +/*
693 + * regcomp and regexec -- regsub and regerror are elsewhere
694 + * @(#)regexp.c 1.3 of 18 April 87
695 + *
696 + * Copyright (c) 1986 by University of Toronto.
697 + * Written by Henry Spencer. Not derived from licensed software.
698 + *
699 + * Permission is granted to anyone to use this software for any
700 + * purpose on any computer system, and to redistribute it freely,
701 + * subject to the following restrictions:
702 + *
703 + * 1. The author is not responsible for the consequences of use of
704 + * this software, no matter how awful, even if they arise
705 + * from defects in it.
706 + *
707 + * 2. The origin of this software must not be misrepresented, either
708 + * by explicit claim or by omission.
709 + *
710 + * 3. Altered versions must be plainly marked as such, and must not
711 + * be misrepresented as being the original software.
712 + *
713 + * Beware that some of this code is subtly aware of the way operator
714 + * precedence is structured in regular expressions. Serious changes in
715 + * regular-expression syntax might require a total rethink.
716 + *
717 + * This code was modified by Ethan Sommer to work within the kernel
718 + * (it now uses kmalloc etc..)
719 + *
720 + * Modified slightly by Matthew Strait to use more modern C.
721 + */
722 +
723 +#include "regexp.h"
724 +#include "regmagic.h"
725 +
726 +/* added by ethan and matt. Lets it work in both kernel and user space.
727 +(So iptables can use it, for instance.) Yea, it goes both ways... */
728 +#if __KERNEL__
729 + #define malloc(foo) kmalloc(foo,GFP_ATOMIC)
730 +#else
731 + #define printk(format,args...) printf(format,##args)
732 +#endif
733 +
734 +void regerror(char * s)
735 +{
736 + printk("<3>Regexp: %s\n", s);
737 + /* NOTREACHED */
738 +}
739 +
740 +/*
741 + * The "internal use only" fields in regexp.h are present to pass info from
742 + * compile to execute that permits the execute phase to run lots faster on
743 + * simple cases. They are:
744 + *
745 + * regstart char that must begin a match; '\0' if none obvious
746 + * reganch is the match anchored (at beginning-of-line only)?
747 + * regmust string (pointer into program) that match must include, or NULL
748 + * regmlen length of regmust string
749 + *
750 + * Regstart and reganch permit very fast decisions on suitable starting points
751 + * for a match, cutting down the work a lot. Regmust permits fast rejection
752 + * of lines that cannot possibly match. The regmust tests are costly enough
753 + * that regcomp() supplies a regmust only if the r.e. contains something
754 + * potentially expensive (at present, the only such thing detected is * or +
755 + * at the start of the r.e., which can involve a lot of backup). Regmlen is
756 + * supplied because the test in regexec() needs it and regcomp() is computing
757 + * it anyway.
758 + */
759 +
760 +/*
761 + * Structure for regexp "program". This is essentially a linear encoding
762 + * of a nondeterministic finite-state machine (aka syntax charts or
763 + * "railroad normal form" in parsing technology). Each node is an opcode
764 + * plus a "next" pointer, possibly plus an operand. "Next" pointers of
765 + * all nodes except BRANCH implement concatenation; a "next" pointer with
766 + * a BRANCH on both ends of it is connecting two alternatives. (Here we
767 + * have one of the subtle syntax dependencies: an individual BRANCH (as
768 + * opposed to a collection of them) is never concatenated with anything
769 + * because of operator precedence.) The operand of some types of node is
770 + * a literal string; for others, it is a node leading into a sub-FSM. In
771 + * particular, the operand of a BRANCH node is the first node of the branch.
772 + * (NB this is *not* a tree structure: the tail of the branch connects
773 + * to the thing following the set of BRANCHes.) The opcodes are:
774 + */
775 +
776 +/* definition number opnd? meaning */
777 +#define END 0 /* no End of program. */
778 +#define BOL 1 /* no Match "" at beginning of line. */
779 +#define EOL 2 /* no Match "" at end of line. */
780 +#define ANY 3 /* no Match any one character. */
781 +#define ANYOF 4 /* str Match any character in this string. */
782 +#define ANYBUT 5 /* str Match any character not in this string. */
783 +#define BRANCH 6 /* node Match this alternative, or the next... */
784 +#define BACK 7 /* no Match "", "next" ptr points backward. */
785 +#define EXACTLY 8 /* str Match this string. */
786 +#define NOTHING 9 /* no Match empty string. */
787 +#define STAR 10 /* node Match this (simple) thing 0 or more times. */
788 +#define PLUS 11 /* node Match this (simple) thing 1 or more times. */
789 +#define OPEN 20 /* no Mark this point in input as start of #n. */
790 + /* OPEN+1 is number 1, etc. */
791 +#define CLOSE 30 /* no Analogous to OPEN. */
792 +
793 +/*
794 + * Opcode notes:
795 + *
796 + * BRANCH The set of branches constituting a single choice are hooked
797 + * together with their "next" pointers, since precedence prevents
798 + * anything being concatenated to any individual branch. The
799 + * "next" pointer of the last BRANCH in a choice points to the
800 + * thing following the whole choice. This is also where the
801 + * final "next" pointer of each individual branch points; each
802 + * branch starts with the operand node of a BRANCH node.
803 + *
804 + * BACK Normal "next" pointers all implicitly point forward; BACK
805 + * exists to make loop structures possible.
806 + *
807 + * STAR,PLUS '?', and complex '*' and '+', are implemented as circular
808 + * BRANCH structures using BACK. Simple cases (one character
809 + * per match) are implemented with STAR and PLUS for speed
810 + * and to minimize recursive plunges.
811 + *
812 + * OPEN,CLOSE ...are numbered at compile time.
813 + */
814 +
815 +/*
816 + * A node is one char of opcode followed by two chars of "next" pointer.
817 + * "Next" pointers are stored as two 8-bit pieces, high order first. The
818 + * value is a positive offset from the opcode of the node containing it.
819 + * An operand, if any, simply follows the node. (Note that much of the
820 + * code generation knows about this implicit relationship.)
821 + *
822 + * Using two bytes for the "next" pointer is vast overkill for most things,
823 + * but allows patterns to get big without disasters.
824 + */
825 +#define OP(p) (*(p))
826 +#define NEXT(p) (((*((p)+1)&0377)<<8) + (*((p)+2)&0377))
827 +#define OPERAND(p) ((p) + 3)
828 +
829 +/*
830 + * See regmagic.h for one further detail of program structure.
831 + */
832 +
833 +
834 +/*
835 + * Utility definitions.
836 + */
837 +#ifndef CHARBITS
838 +#define UCHARAT(p) ((int)*(unsigned char *)(p))
839 +#else
840 +#define UCHARAT(p) ((int)*(p)&CHARBITS)
841 +#endif
842 +
843 +#define FAIL(m) { regerror(m); return(NULL); }
844 +#define ISMULT(c) ((c) == '*' || (c) == '+' || (c) == '?')
845 +#define META "^$.[()|?+*\\"
846 +
847 +/*
848 + * Flags to be passed up and down.
849 + */
850 +#define HASWIDTH 01 /* Known never to match null string. */
851 +#define SIMPLE 02 /* Simple enough to be STAR/PLUS operand. */
852 +#define SPSTART 04 /* Starts with * or +. */
853 +#define WORST 0 /* Worst case. */
854 +
855 +/*
856 + * Global work variables for regcomp().
857 + */
858 +static char *regparse; /* Input-scan pointer. */
859 +static int regnpar; /* () count. */
860 +static char regdummy;
861 +static char *regcode; /* Code-emit pointer; &regdummy = don't. */
862 +static long regsize; /* Code size. */
863 +
864 +/*
865 + * Forward declarations for regcomp()'s friends.
866 + */
867 +#ifndef STATIC
868 +#define STATIC static
869 +#endif
870 +STATIC char *reg(int paren,int *flagp);
871 +STATIC char *regbranch(int *flagp);
872 +STATIC char *regpiece(int *flagp);
873 +STATIC char *regatom(int *flagp);
874 +STATIC char *regnode(char op);
875 +STATIC char *regnext(char *p);
876 +STATIC void regc(char b);
877 +STATIC void reginsert(char op, char *opnd);
878 +STATIC void regtail(char *p, char *val);
879 +STATIC void regoptail(char *p, char *val);
880 +
881 +
882 +__kernel_size_t my_strcspn(const char *s1,const char *s2)
883 +{
884 + char *scan1;
885 + char *scan2;
886 + int count;
887 +
888 + count = 0;
889 + for (scan1 = (char *)s1; *scan1 != '\0'; scan1++) {
890 + for (scan2 = (char *)s2; *scan2 != '\0';) /* ++ moved down. */
891 + if (*scan1 == *scan2++)
892 + return(count);
893 + count++;
894 + }
895 + return(count);
896 +}
897 +
898 +/*
899 + - regcomp - compile a regular expression into internal code
900 + *
901 + * We can't allocate space until we know how big the compiled form will be,
902 + * but we can't compile it (and thus know how big it is) until we've got a
903 + * place to put the code. So we cheat: we compile it twice, once with code
904 + * generation turned off and size counting turned on, and once "for real".
905 + * This also means that we don't allocate space until we are sure that the
906 + * thing really will compile successfully, and we never have to move the
907 + * code and thus invalidate pointers into it. (Note that it has to be in
908 + * one piece because free() must be able to free it all.)
909 + *
910 + * Beware that the optimization-preparation code in here knows about some
911 + * of the structure of the compiled regexp.
912 + */
913 +regexp *
914 +regcomp(char *exp,int *patternsize)
915 +{
916 + register regexp *r;
917 + register char *scan;
918 + register char *longest;
919 + register int len;
920 + int flags;
921 + /* commented out by ethan
922 + extern char *malloc();
923 + */
924 +
925 + if (exp == NULL)
926 + FAIL("NULL argument");
927 +
928 + /* First pass: determine size, legality. */
929 + regparse = exp;
930 + regnpar = 1;
931 + regsize = 0L;
932 + regcode = &regdummy;
933 + regc(MAGIC);
934 + if (reg(0, &flags) == NULL)
935 + return(NULL);
936 +
937 + /* Small enough for pointer-storage convention? */
938 + if (regsize >= 32767L) /* Probably could be 65535L. */
939 + FAIL("regexp too big");
940 +
941 + /* Allocate space. */
942 + *patternsize=sizeof(regexp) + (unsigned)regsize;
943 + r = (regexp *)malloc(sizeof(regexp) + (unsigned)regsize);
944 + if (r == NULL)
945 + FAIL("out of space");
946 +
947 + /* Second pass: emit code. */
948 + regparse = exp;
949 + regnpar = 1;
950 + regcode = r->program;
951 + regc(MAGIC);
952 + if (reg(0, &flags) == NULL)
953 + return(NULL);
954 +
955 + /* Dig out information for optimizations. */
956 + r->regstart = '\0'; /* Worst-case defaults. */
957 + r->reganch = 0;
958 + r->regmust = NULL;
959 + r->regmlen = 0;
960 + scan = r->program+1; /* First BRANCH. */
961 + if (OP(regnext(scan)) == END) { /* Only one top-level choice. */
962 + scan = OPERAND(scan);
963 +
964 + /* Starting-point info. */
965 + if (OP(scan) == EXACTLY)
966 + r->regstart = *OPERAND(scan);
967 + else if (OP(scan) == BOL)
968 + r->reganch++;
969 +
970 + /*
971 + * If there's something expensive in the r.e., find the
972 + * longest literal string that must appear and make it the
973 + * regmust. Resolve ties in favor of later strings, since
974 + * the regstart check works with the beginning of the r.e.
975 + * and avoiding duplication strengthens checking. Not a
976 + * strong reason, but sufficient in the absence of others.
977 + */
978 + if (flags&SPSTART) {
979 + longest = NULL;
980 + len = 0;
981 + for (; scan != NULL; scan = regnext(scan))
982 + if (OP(scan) == EXACTLY && strlen(OPERAND(scan)) >= len) {
983 + longest = OPERAND(scan);
984 + len = strlen(OPERAND(scan));
985 + }
986 + r->regmust = longest;
987 + r->regmlen = len;
988 + }
989 + }
990 +
991 + return(r);
992 +}
993 +
994 +/*
995 + - reg - regular expression, i.e. main body or parenthesized thing
996 + *
997 + * Caller must absorb opening parenthesis.
998 + *
999 + * Combining parenthesis handling with the base level of regular expression
1000 + * is a trifle forced, but the need to tie the tails of the branches to what
1001 + * follows makes it hard to avoid.
1002 + */
1003 +static char *
1004 +reg(int paren, int *flagp /* Parenthesized? */ )
1005 +{
1006 + register char *ret;
1007 + register char *br;
1008 + register char *ender;
1009 + register int parno = 0; /* 0 makes gcc happy */
1010 + int flags;
1011 +
1012 + *flagp = HASWIDTH; /* Tentatively. */
1013 +
1014 + /* Make an OPEN node, if parenthesized. */
1015 + if (paren) {
1016 + if (regnpar >= NSUBEXP)
1017 + FAIL("too many ()");
1018 + parno = regnpar;
1019 + regnpar++;
1020 + ret = regnode(OPEN+parno);
1021 + } else
1022 + ret = NULL;
1023 +
1024 + /* Pick up the branches, linking them together. */
1025 + br = regbranch(&flags);
1026 + if (br == NULL)
1027 + return(NULL);
1028 + if (ret != NULL)
1029 + regtail(ret, br); /* OPEN -> first. */
1030 + else
1031 + ret = br;
1032 + if (!(flags&HASWIDTH))
1033 + *flagp &= ~HASWIDTH;
1034 + *flagp |= flags&SPSTART;
1035 + while (*regparse == '|') {
1036 + regparse++;
1037 + br = regbranch(&flags);
1038 + if (br == NULL)
1039 + return(NULL);
1040 + regtail(ret, br); /* BRANCH -> BRANCH. */
1041 + if (!(flags&HASWIDTH))
1042 + *flagp &= ~HASWIDTH;
1043 + *flagp |= flags&SPSTART;
1044 + }
1045 +
1046 + /* Make a closing node, and hook it on the end. */
1047 + ender = regnode((paren) ? CLOSE+parno : END);
1048 + regtail(ret, ender);
1049 +
1050 + /* Hook the tails of the branches to the closing node. */
1051 + for (br = ret; br != NULL; br = regnext(br))
1052 + regoptail(br, ender);
1053 +
1054 + /* Check for proper termination. */
1055 + if (paren && *regparse++ != ')') {
1056 + FAIL("unmatched ()");
1057 + } else if (!paren && *regparse != '\0') {
1058 + if (*regparse == ')') {
1059 + FAIL("unmatched ()");
1060 + } else
1061 + FAIL("junk on end"); /* "Can't happen". */
1062 + /* NOTREACHED */
1063 + }
1064 +
1065 + return(ret);
1066 +}
1067 +
1068 +/*
1069 + - regbranch - one alternative of an | operator
1070 + *
1071 + * Implements the concatenation operator.
1072 + */
1073 +static char *
1074 +regbranch(int *flagp)
1075 +{
1076 + register char *ret;
1077 + register char *chain;
1078 + register char *latest;
1079 + int flags;
1080 +
1081 + *flagp = WORST; /* Tentatively. */
1082 +
1083 + ret = regnode(BRANCH);
1084 + chain = NULL;
1085 + while (*regparse != '\0' && *regparse != '|' && *regparse != ')') {
1086 + latest = regpiece(&flags);
1087 + if (latest == NULL)
1088 + return(NULL);
1089 + *flagp |= flags&HASWIDTH;
1090 + if (chain == NULL) /* First piece. */
1091 + *flagp |= flags&SPSTART;
1092 + else
1093 + regtail(chain, latest);
1094 + chain = latest;
1095 + }
1096 + if (chain == NULL) /* Loop ran zero times. */
1097 + (void) regnode(NOTHING);
1098 +
1099 + return(ret);
1100 +}
1101 +
1102 +/*
1103 + - regpiece - something followed by possible [*+?]
1104 + *
1105 + * Note that the branching code sequences used for ? and the general cases
1106 + * of * and + are somewhat optimized: they use the same NOTHING node as
1107 + * both the endmarker for their branch list and the body of the last branch.
1108 + * It might seem that this node could be dispensed with entirely, but the
1109 + * endmarker role is not redundant.
1110 + */
1111 +static char *
1112 +regpiece(int *flagp)
1113 +{
1114 + register char *ret;
1115 + register char op;
1116 + register char *next;
1117 + int flags;
1118 +
1119 + ret = regatom(&flags);
1120 + if (ret == NULL)
1121 + return(NULL);
1122 +
1123 + op = *regparse;
1124 + if (!ISMULT(op)) {
1125 + *flagp = flags;
1126 + return(ret);
1127 + }
1128 +
1129 + if (!(flags&HASWIDTH) && op != '?')
1130 + FAIL("*+ operand could be empty");
1131 + *flagp = (op != '+') ? (WORST|SPSTART) : (WORST|HASWIDTH);
1132 +
1133 + if (op == '*' && (flags&SIMPLE))
1134 + reginsert(STAR, ret);
1135 + else if (op == '*') {
1136 + /* Emit x* as (x&|), where & means "self". */
1137 + reginsert(BRANCH, ret); /* Either x */
1138 + regoptail(ret, regnode(BACK)); /* and loop */
1139 + regoptail(ret, ret); /* back */
1140 + regtail(ret, regnode(BRANCH)); /* or */
1141 + regtail(ret, regnode(NOTHING)); /* null. */
1142 + } else if (op == '+' && (flags&SIMPLE))
1143 + reginsert(PLUS, ret);
1144 + else if (op == '+') {
1145 + /* Emit x+ as x(&|), where & means "self". */
1146 + next = regnode(BRANCH); /* Either */
1147 + regtail(ret, next);
1148 + regtail(regnode(BACK), ret); /* loop back */
1149 + regtail(next, regnode(BRANCH)); /* or */
1150 + regtail(ret, regnode(NOTHING)); /* null. */
1151 + } else if (op == '?') {
1152 + /* Emit x? as (x|) */
1153 + reginsert(BRANCH, ret); /* Either x */
1154 + regtail(ret, regnode(BRANCH)); /* or */
1155 + next = regnode(NOTHING); /* null. */
1156 + regtail(ret, next);
1157 + regoptail(ret, next);
1158 + }
1159 + regparse++;
1160 + if (ISMULT(*regparse))
1161 + FAIL("nested *?+");
1162 +
1163 + return(ret);
1164 +}
1165 +
1166 +/*
1167 + - regatom - the lowest level
1168 + *
1169 + * Optimization: gobbles an entire sequence of ordinary characters so that
1170 + * it can turn them into a single node, which is smaller to store and
1171 + * faster to run. Backslashed characters are exceptions, each becoming a
1172 + * separate node; the code is simpler that way and it's not worth fixing.
1173 + */
1174 +static char *
1175 +regatom(int *flagp)
1176 +{
1177 + register char *ret;
1178 + int flags;
1179 +
1180 + *flagp = WORST; /* Tentatively. */
1181 +
1182 + switch (*regparse++) {
1183 + case '^':
1184 + ret = regnode(BOL);
1185 + break;
1186 + case '$':
1187 + ret = regnode(EOL);
1188 + break;
1189 + case '.':
1190 + ret = regnode(ANY);
1191 + *flagp |= HASWIDTH|SIMPLE;
1192 + break;
1193 + case '[': {
1194 + register int class;
1195 + register int classend;
1196 +
1197 + if (*regparse == '^') { /* Complement of range. */
1198 + ret = regnode(ANYBUT);
1199 + regparse++;
1200 + } else
1201 + ret = regnode(ANYOF);
1202 + if (*regparse == ']' || *regparse == '-')
1203 + regc(*regparse++);
1204 + while (*regparse != '\0' && *regparse != ']') {
1205 + if (*regparse == '-') {
1206 + regparse++;
1207 + if (*regparse == ']' || *regparse == '\0')
1208 + regc('-');
1209 + else {
1210 + class = UCHARAT(regparse-2)+1;
1211 + classend = UCHARAT(regparse);
1212 + if (class > classend+1)
1213 + FAIL("invalid [] range");
1214 + for (; class <= classend; class++)
1215 + regc(class);
1216 + regparse++;
1217 + }
1218 + } else
1219 + regc(*regparse++);
1220 + }
1221 + regc('\0');
1222 + if (*regparse != ']')
1223 + FAIL("unmatched []");
1224 + regparse++;
1225 + *flagp |= HASWIDTH|SIMPLE;
1226 + }
1227 + break;
1228 + case '(':
1229 + ret = reg(1, &flags);
1230 + if (ret == NULL)
1231 + return(NULL);
1232 + *flagp |= flags&(HASWIDTH|SPSTART);
1233 + break;
1234 + case '\0':
1235 + case '|':
1236 + case ')':
1237 + FAIL("internal urp"); /* Supposed to be caught earlier. */
1238 + break;
1239 + case '?':
1240 + case '+':
1241 + case '*':
1242 + FAIL("?+* follows nothing");
1243 + break;
1244 + case '\\':
1245 + if (*regparse == '\0')
1246 + FAIL("trailing \\");
1247 + ret = regnode(EXACTLY);
1248 + regc(*regparse++);
1249 + regc('\0');
1250 + *flagp |= HASWIDTH|SIMPLE;
1251 + break;
1252 + default: {
1253 + register int len;
1254 + register char ender;
1255 +
1256 + regparse--;
1257 + len = my_strcspn((const char *)regparse, (const char *)META);
1258 + if (len <= 0)
1259 + FAIL("internal disaster");
1260 + ender = *(regparse+len);
1261 + if (len > 1 && ISMULT(ender))
1262 + len--; /* Back off clear of ?+* operand. */
1263 + *flagp |= HASWIDTH;
1264 + if (len == 1)
1265 + *flagp |= SIMPLE;
1266 + ret = regnode(EXACTLY);
1267 + while (len > 0) {
1268 + regc(*regparse++);
1269 + len--;
1270 + }
1271 + regc('\0');
1272 + }
1273 + break;
1274 + }
1275 +
1276 + return(ret);
1277 +}
1278 +
1279 +/*
1280 + - regnode - emit a node
1281 + */
1282 +static char * /* Location. */
1283 +regnode(char op)
1284 +{
1285 + register char *ret;
1286 + register char *ptr;
1287 +
1288 + ret = regcode;
1289 + if (ret == &regdummy) {
1290 + regsize += 3;
1291 + return(ret);
1292 + }
1293 +
1294 + ptr = ret;
1295 + *ptr++ = op;
1296 + *ptr++ = '\0'; /* Null "next" pointer. */
1297 + *ptr++ = '\0';
1298 + regcode = ptr;
1299 +
1300 + return(ret);
1301 +}
1302 +
1303 +/*
1304 + - regc - emit (if appropriate) a byte of code
1305 + */
1306 +static void
1307 +regc(char b)
1308 +{
1309 + if (regcode != &regdummy)
1310 + *regcode++ = b;
1311 + else
1312 + regsize++;
1313 +}
1314 +
1315 +/*
1316 + - reginsert - insert an operator in front of already-emitted operand
1317 + *
1318 + * Means relocating the operand.
1319 + */
1320 +static void
1321 +reginsert(char op, char* opnd)
1322 +{
1323 + register char *src;
1324 + register char *dst;
1325 + register char *place;
1326 +
1327 + if (regcode == &regdummy) {
1328 + regsize += 3;
1329 + return;
1330 + }
1331 +
1332 + src = regcode;
1333 + regcode += 3;
1334 + dst = regcode;
1335 + while (src > opnd)
1336 + *--dst = *--src;
1337 +
1338 + place = opnd; /* Op node, where operand used to be. */
1339 + *place++ = op;
1340 + *place++ = '\0';
1341 + *place++ = '\0';
1342 +}
1343 +
1344 +/*
1345 + - regtail - set the next-pointer at the end of a node chain
1346 + */
1347 +static void
1348 +regtail(char *p, char *val)
1349 +{
1350 + register char *scan;
1351 + register char *temp;
1352 + register int offset;
1353 +
1354 + if (p == &regdummy)
1355 + return;
1356 +
1357 + /* Find last node. */
1358 + scan = p;
1359 + for (;;) {
1360 + temp = regnext(scan);
1361 + if (temp == NULL)
1362 + break;
1363 + scan = temp;
1364 + }
1365 +
1366 + if (OP(scan) == BACK)
1367 + offset = scan - val;
1368 + else
1369 + offset = val - scan;
1370 + *(scan+1) = (offset>>8)&0377;
1371 + *(scan+2) = offset&0377;
1372 +}
1373 +
1374 +/*
1375 + - regoptail - regtail on operand of first argument; nop if operandless
1376 + */
1377 +static void
1378 +regoptail(char *p, char *val)
1379 +{
1380 + /* "Operandless" and "op != BRANCH" are synonymous in practice. */
1381 + if (p == NULL || p == &regdummy || OP(p) != BRANCH)
1382 + return;
1383 + regtail(OPERAND(p), val);
1384 +}
1385 +
1386 +/*
1387 + * regexec and friends
1388 + */
1389 +
1390 +/*
1391 + * Global work variables for regexec().
1392 + */
1393 +static char *reginput; /* String-input pointer. */
1394 +static char *regbol; /* Beginning of input, for ^ check. */
1395 +static char **regstartp; /* Pointer to startp array. */
1396 +static char **regendp; /* Ditto for endp. */
1397 +
1398 +/*
1399 + * Forwards.
1400 + */
1401 +STATIC int regtry(regexp *prog, char *string);
1402 +STATIC int regmatch(char *prog);
1403 +STATIC int regrepeat(char *p);
1404 +
1405 +#ifdef DEBUG
1406 +int regnarrate = 0;
1407 +void regdump();
1408 +STATIC char *regprop(char *op);
1409 +#endif
1410 +
1411 +/*
1412 + - regexec - match a regexp against a string
1413 + */
1414 +int
1415 +regexec(regexp *prog, char *string)
1416 +{
1417 + register char *s;
1418 +
1419 + /* Be paranoid... */
1420 + if (prog == NULL || string == NULL) {
1421 + printk("<3>Regexp: NULL parameter\n");
1422 + return(0);
1423 + }
1424 +
1425 + /* Check validity of program. */
1426 + if (UCHARAT(prog->program) != MAGIC) {
1427 + printk("<3>Regexp: corrupted program\n");
1428 + return(0);
1429 + }
1430 +
1431 + /* If there is a "must appear" string, look for it. */
1432 + if (prog->regmust != NULL) {
1433 + s = string;
1434 + while ((s = strchr(s, prog->regmust[0])) != NULL) {
1435 + if (strncmp(s, prog->regmust, prog->regmlen) == 0)
1436 + break; /* Found it. */
1437 + s++;
1438 + }
1439 + if (s == NULL) /* Not present. */
1440 + return(0);
1441 + }
1442 +
1443 + /* Mark beginning of line for ^ . */
1444 + regbol = string;
1445 +
1446 + /* Simplest case: anchored match need be tried only once. */
1447 + if (prog->reganch)
1448 + return(regtry(prog, string));
1449 +
1450 + /* Messy cases: unanchored match. */
1451 + s = string;
1452 + if (prog->regstart != '\0')
1453 + /* We know what char it must start with. */
1454 + while ((s = strchr(s, prog->regstart)) != NULL) {
1455 + if (regtry(prog, s))
1456 + return(1);
1457 + s++;
1458 + }
1459 + else
1460 + /* We don't -- general case. */
1461 + do {
1462 + if (regtry(prog, s))
1463 + return(1);
1464 + } while (*s++ != '\0');
1465 +
1466 + /* Failure. */
1467 + return(0);
1468 +}
1469 +
1470 +/*
1471 + - regtry - try match at specific point
1472 + */
1473 +static int /* 0 failure, 1 success */
1474 +regtry(regexp *prog, char *string)
1475 +{
1476 + register int i;
1477 + register char **sp;
1478 + register char **ep;
1479 +
1480 + reginput = string;
1481 + regstartp = prog->startp;
1482 + regendp = prog->endp;
1483 +
1484 + sp = prog->startp;
1485 + ep = prog->endp;
1486 + for (i = NSUBEXP; i > 0; i--) {
1487 + *sp++ = NULL;
1488 + *ep++ = NULL;
1489 + }
1490 + if (regmatch(prog->program + 1)) {
1491 + prog->startp[0] = string;
1492 + prog->endp[0] = reginput;
1493 + return(1);
1494 + } else
1495 + return(0);
1496 +}
1497 +
1498 +/*
1499 + - regmatch - main matching routine
1500 + *
1501 + * Conceptually the strategy is simple: check to see whether the current
1502 + * node matches, call self recursively to see whether the rest matches,
1503 + * and then act accordingly. In practice we make some effort to avoid
1504 + * recursion, in particular by going through "ordinary" nodes (that don't
1505 + * need to know whether the rest of the match failed) by a loop instead of
1506 + * by recursion.
1507 + */
1508 +static int /* 0 failure, 1 success */
1509 +regmatch(char *prog)
1510 +{
1511 + register char *scan = prog; /* Current node. */
1512 + char *next; /* Next node. */
1513 +
1514 +#ifdef DEBUG
1515 + if (scan != NULL && regnarrate)
1516 + fprintf(stderr, "%s(\n", regprop(scan));
1517 +#endif
1518 + while (scan != NULL) {
1519 +#ifdef DEBUG
1520 + if (regnarrate)
1521 + fprintf(stderr, "%s...\n", regprop(scan));
1522 +#endif
1523 + next = regnext(scan);
1524 +
1525 + switch (OP(scan)) {
1526 + case BOL:
1527 + if (reginput != regbol)
1528 + return(0);
1529 + break;
1530 + case EOL:
1531 + if (*reginput != '\0')
1532 + return(0);
1533 + break;
1534 + case ANY:
1535 + if (*reginput == '\0')
1536 + return(0);
1537 + reginput++;
1538 + break;
1539 + case EXACTLY: {
1540 + register int len;
1541 + register char *opnd;
1542 +
1543 + opnd = OPERAND(scan);
1544 + /* Inline the first character, for speed. */
1545 + if (*opnd != *reginput)
1546 + return(0);
1547 + len = strlen(opnd);
1548 + if (len > 1 && strncmp(opnd, reginput, len) != 0)
1549 + return(0);
1550 + reginput += len;
1551 + }
1552 + break;
1553 + case ANYOF:
1554 + if (*reginput == '\0' || strchr(OPERAND(scan), *reginput) == NULL)
1555 + return(0);
1556 + reginput++;
1557 + break;
1558 + case ANYBUT:
1559 + if (*reginput == '\0' || strchr(OPERAND(scan), *reginput) != NULL)
1560 + return(0);
1561 + reginput++;
1562 + break;
1563 + case NOTHING:
1564 + case BACK:
1565 + break;
1566 + case OPEN+1:
1567 + case OPEN+2:
1568 + case OPEN+3:
1569 + case OPEN+4:
1570 + case OPEN+5:
1571 + case OPEN+6:
1572 + case OPEN+7:
1573 + case OPEN+8:
1574 + case OPEN+9: {
1575 + register int no;
1576 + register char *save;
1577 +
1578 + no = OP(scan) - OPEN;
1579 + save = reginput;
1580 +
1581 + if (regmatch(next)) {
1582 + /*
1583 + * Don't set startp if some later
1584 + * invocation of the same parentheses
1585 + * already has.
1586 + */
1587 + if (regstartp[no] == NULL)
1588 + regstartp[no] = save;
1589 + return(1);
1590 + } else
1591 + return(0);
1592 + }
1593 + break;
1594 + case CLOSE+1:
1595 + case CLOSE+2:
1596 + case CLOSE+3:
1597 + case CLOSE+4:
1598 + case CLOSE+5:
1599 + case CLOSE+6:
1600 + case CLOSE+7:
1601 + case CLOSE+8:
1602 + case CLOSE+9:
1603 + {
1604 + register int no;
1605 + register char *save;
1606 +
1607 + no = OP(scan) - CLOSE;
1608 + save = reginput;
1609 +
1610 + if (regmatch(next)) {
1611 + /*
1612 + * Don't set endp if some later
1613 + * invocation of the same parentheses
1614 + * already has.
1615 + */
1616 + if (regendp[no] == NULL)
1617 + regendp[no] = save;
1618 + return(1);
1619 + } else
1620 + return(0);
1621 + }
1622 + break;
1623 + case BRANCH: {
1624 + register char *save;
1625 +
1626 + if (OP(next) != BRANCH) /* No choice. */
1627 + next = OPERAND(scan); /* Avoid recursion. */
1628 + else {
1629 + do {
1630 + save = reginput;
1631 + if (regmatch(OPERAND(scan)))
1632 + return(1);
1633 + reginput = save;
1634 + scan = regnext(scan);
1635 + } while (scan != NULL && OP(scan) == BRANCH);
1636 + return(0);
1637 + /* NOTREACHED */
1638 + }
1639 + }
1640 + break;
1641 + case STAR:
1642 + case PLUS: {
1643 + register char nextch;
1644 + register int no;
1645 + register char *save;
1646 + register int min;
1647 +
1648 + /*
1649 + * Lookahead to avoid useless match attempts
1650 + * when we know what character comes next.
1651 + */
1652 + nextch = '\0';
1653 + if (OP(next) == EXACTLY)
1654 + nextch = *OPERAND(next);
1655 + min = (OP(scan) == STAR) ? 0 : 1;
1656 + save = reginput;
1657 + no = regrepeat(OPERAND(scan));
1658 + while (no >= min) {
1659 + /* If it could work, try it. */
1660 + if (nextch == '\0' || *reginput == nextch)
1661 + if (regmatch(next))
1662 + return(1);
1663 + /* Couldn't or didn't -- back up. */
1664 + no--;
1665 + reginput = save + no;
1666 + }
1667 + return(0);
1668 + }
1669 + break;
1670 + case END:
1671 + return(1); /* Success! */
1672 + break;
1673 + default:
1674 + printk("<3>Regexp: memory corruption\n");
1675 + return(0);
1676 + break;
1677 + }
1678 +
1679 + scan = next;
1680 + }
1681 +
1682 + /*
1683 + * We get here only if there's trouble -- normally "case END" is
1684 + * the terminating point.
1685 + */
1686 + printk("<3>Regexp: corrupted pointers\n");
1687 + return(0);
1688 +}
1689 +
1690 +/*
1691 + - regrepeat - repeatedly match something simple, report how many
1692 + */
1693 +static int
1694 +regrepeat(char *p)
1695 +{
1696 + register int count = 0;
1697 + register char *scan;
1698 + register char *opnd;
1699 +
1700 + scan = reginput;
1701 + opnd = OPERAND(p);
1702 + switch (OP(p)) {
1703 + case ANY:
1704 + count = strlen(scan);
1705 + scan += count;
1706 + break;
1707 + case EXACTLY:
1708 + while (*opnd == *scan) {
1709 + count++;
1710 + scan++;
1711 + }
1712 + break;
1713 + case ANYOF:
1714 + while (*scan != '\0' && strchr(opnd, *scan) != NULL) {
1715 + count++;
1716 + scan++;
1717 + }
1718 + break;
1719 + case ANYBUT:
1720 + while (*scan != '\0' && strchr(opnd, *scan) == NULL) {
1721 + count++;
1722 + scan++;
1723 + }
1724 + break;
1725 + default: /* Oh dear. Called inappropriately. */
1726 + printk("<3>Regexp: internal foulup\n");
1727 + count = 0; /* Best compromise. */
1728 + break;
1729 + }
1730 + reginput = scan;
1731 +
1732 + return(count);
1733 +}
1734 +
1735 +/*
1736 + - regnext - dig the "next" pointer out of a node
1737 + */
1738 +static char*
1739 +regnext(char *p)
1740 +{
1741 + register int offset;
1742 +
1743 + if (p == &regdummy)
1744 + return(NULL);
1745 +
1746 + offset = NEXT(p);
1747 + if (offset == 0)
1748 + return(NULL);
1749 +
1750 + if (OP(p) == BACK)
1751 + return(p-offset);
1752 + else
1753 + return(p+offset);
1754 +}
1755 +
1756 +#ifdef DEBUG
1757 +
1758 +STATIC char *regprop();
1759 +
1760 +/*
1761 + - regdump - dump a regexp onto stdout in vaguely comprehensible form
1762 + */
1763 +void
1764 +regdump(regexp *r)
1765 +{
1766 + register char *s;
1767 + register char op = EXACTLY; /* Arbitrary non-END op. */
1768 + register char *next;
1769 + /* extern char *strchr(); */
1770 +
1771 +
1772 + s = r->program + 1;
1773 + while (op != END) { /* While that wasn't END last time... */
1774 + op = OP(s);
1775 + printf("%2d%s", s-r->program, regprop(s)); /* Where, what. */
1776 + next = regnext(s);
1777 + if (next == NULL) /* Next ptr. */
1778 + printf("(0)");
1779 + else
1780 + printf("(%d)", (s-r->program)+(next-s));
1781 + s += 3;
1782 + if (op == ANYOF || op == ANYBUT || op == EXACTLY) {
1783 + /* Literal string, where present. */
1784 + while (*s != '\0') {
1785 + putchar(*s);
1786 + s++;
1787 + }
1788 + s++;
1789 + }
1790 + putchar('\n');
1791 + }
1792 +
1793 + /* Header fields of interest. */
1794 + if (r->regstart != '\0')
1795 + printf("start `%c' ", r->regstart);
1796 + if (r->reganch)
1797 + printf("anchored ");
1798 + if (r->regmust != NULL)
1799 + printf("must have \"%s\"", r->regmust);
1800 + printf("\n");
1801 +}
1802 +
1803 +/*
1804 + - regprop - printable representation of opcode
1805 + */
1806 +static char *
1807 +regprop(char *op)
1808 +{
1809 +#define BUFLEN 50
1810 + register char *p;
1811 + static char buf[BUFLEN];
1812 +
1813 + strcpy(buf, ":");
1814 +
1815 + switch (OP(op)) {
1816 + case BOL:
1817 + p = "BOL";
1818 + break;
1819 + case EOL:
1820 + p = "EOL";
1821 + break;
1822 + case ANY:
1823 + p = "ANY";
1824 + break;
1825 + case ANYOF:
1826 + p = "ANYOF";
1827 + break;
1828 + case ANYBUT:
1829 + p = "ANYBUT";
1830 + break;
1831 + case BRANCH:
1832 + p = "BRANCH";
1833 + break;
1834 + case EXACTLY:
1835 + p = "EXACTLY";
1836 + break;
1837 + case NOTHING:
1838 + p = "NOTHING";
1839 + break;
1840 + case BACK:
1841 + p = "BACK";
1842 + break;
1843 + case END:
1844 + p = "END";
1845 + break;
1846 + case OPEN+1:
1847 + case OPEN+2:
1848 + case OPEN+3:
1849 + case OPEN+4:
1850 + case OPEN+5:
1851 + case OPEN+6:
1852 + case OPEN+7:
1853 + case OPEN+8:
1854 + case OPEN+9:
1855 + snprintf(buf+strlen(buf),BUFLEN-strlen(buf), "OPEN%d", OP(op)-OPEN);
1856 + p = NULL;
1857 + break;
1858 + case CLOSE+1:
1859 + case CLOSE+2:
1860 + case CLOSE+3:
1861 + case CLOSE+4:
1862 + case CLOSE+5:
1863 + case CLOSE+6:
1864 + case CLOSE+7:
1865 + case CLOSE+8:
1866 + case CLOSE+9:
1867 + snprintf(buf+strlen(buf),BUFLEN-strlen(buf), "CLOSE%d", OP(op)-CLOSE);
1868 + p = NULL;
1869 + break;
1870 + case STAR:
1871 + p = "STAR";
1872 + break;
1873 + case PLUS:
1874 + p = "PLUS";
1875 + break;
1876 + default:
1877 + printk("<3>Regexp: corrupted opcode\n");
1878 + break;
1879 + }
1880 + if (p != NULL)
1881 + strncat(buf, p, BUFLEN-strlen(buf));
1882 + return(buf);
1883 +}
1884 +#endif
1885 +
1886 +
1887 --- linux-2.6.14/net/ipv4/netfilter/regexp/regexp.h 1969-12-31 18:00:00.000000000 -0600
1888 +++ linux-2.6.14-layer7/net/ipv4/netfilter/regexp/regexp.h 2005-11-12 17:31:34.000000000 -0600
1889 @@ -0,0 +1,41 @@
1890 +/*
1891 + * Definitions etc. for regexp(3) routines.
1892 + *
1893 + * Caveat: this is V8 regexp(3) [actually, a reimplementation thereof],
1894 + * not the System V one.
1895 + */
1896 +
1897 +#ifndef REGEXP_H
1898 +#define REGEXP_H
1899 +
1900 +
1901 +/*
1902 +http://www.opensource.apple.com/darwinsource/10.3/expect-1/expect/expect.h ,
1903 +which contains a version of this library, says:
1904 +
1905 + *
1906 + * NSUBEXP must be at least 10, and no greater than 117 or the parser
1907 + * will not work properly.
1908 + *
1909 +
1910 +However, it looks rather like this library is limited to 10. If you think
1911 +otherwise, let us know.
1912 +*/
1913 +
1914 +#define NSUBEXP 10
1915 +typedef struct regexp {
1916 + char *startp[NSUBEXP];
1917 + char *endp[NSUBEXP];
1918 + char regstart; /* Internal use only. */
1919 + char reganch; /* Internal use only. */
1920 + char *regmust; /* Internal use only. */
1921 + int regmlen; /* Internal use only. */
1922 + char program[1]; /* Unwarranted chumminess with compiler. */
1923 +} regexp;
1924 +
1925 +regexp * regcomp(char *exp, int *patternsize);
1926 +int regexec(regexp *prog, char *string);
1927 +void regsub(regexp *prog, char *source, char *dest);
1928 +void regerror(char *s);
1929 +
1930 +#endif
1931 --- linux-2.6.14/net/ipv4/netfilter/regexp/regmagic.h 1969-12-31 18:00:00.000000000 -0600
1932 +++ linux-2.6.14-layer7/net/ipv4/netfilter/regexp/regmagic.h 2005-11-12 17:31:34.000000000 -0600
1933 @@ -0,0 +1,5 @@
1934 +/*
1935 + * The first byte of the regexp internal "program" is actually this magic
1936 + * number; the start node begins in the second byte.
1937 + */
1938 +#define MAGIC 0234
1939 --- linux-2.6.14/net/ipv4/netfilter/regexp/regsub.c 1969-12-31 18:00:00.000000000 -0600
1940 +++ linux-2.6.14-layer7/net/ipv4/netfilter/regexp/regsub.c 2005-11-12 17:31:34.000000000 -0600
1941 @@ -0,0 +1,95 @@
1942 +/*
1943 + * regsub
1944 + * @(#)regsub.c 1.3 of 2 April 86
1945 + *
1946 + * Copyright (c) 1986 by University of Toronto.
1947 + * Written by Henry Spencer. Not derived from licensed software.
1948 + *
1949 + * Permission is granted to anyone to use this software for any
1950 + * purpose on any computer system, and to redistribute it freely,
1951 + * subject to the following restrictions:
1952 + *
1953 + * 1. The author is not responsible for the consequences of use of
1954 + * this software, no matter how awful, even if they arise
1955 + * from defects in it.
1956 + *
1957 + * 2. The origin of this software must not be misrepresented, either
1958 + * by explicit claim or by omission.
1959 + *
1960 + * 3. Altered versions must be plainly marked as such, and must not
1961 + * be misrepresented as being the original software.
1962 + *
1963 + *
1964 + * This code was modified by Ethan Sommer to work within the kernel
1965 + * (it now uses kmalloc etc..)
1966 + *
1967 + */
1968 +#include "regexp.h"
1969 +#include "regmagic.h"
1970 +#include <linux/string.h>
1971 +
1972 +
1973 +#ifndef CHARBITS
1974 +#define UCHARAT(p) ((int)*(unsigned char *)(p))
1975 +#else
1976 +#define UCHARAT(p) ((int)*(p)&CHARBITS)
1977 +#endif
1978 +
1979 +#if 0
1980 +//void regerror(char * s)
1981 +//{
1982 +// printk("regexp(3): %s", s);
1983 +// /* NOTREACHED */
1984 +//}
1985 +#endif
1986 +
1987 +/*
1988 + - regsub - perform substitutions after a regexp match
1989 + */
1990 +void
1991 +regsub(regexp * prog, char * source, char * dest)
1992 +{
1993 + register char *src;
1994 + register char *dst;
1995 + register char c;
1996 + register int no;
1997 + register int len;
1998 +
1999 + /* Not necessary and gcc doesn't like it -MLS */
2000 + /*extern char *strncpy();*/
2001 +
2002 + if (prog == NULL || source == NULL || dest == NULL) {
2003 + regerror("NULL parm to regsub");
2004 + return;
2005 + }
2006 + if (UCHARAT(prog->program) != MAGIC) {
2007 + regerror("damaged regexp fed to regsub");
2008 + return;
2009 + }
2010 +
2011 + src = source;
2012 + dst = dest;
2013 + while ((c = *src++) != '\0') {
2014 + if (c == '&')
2015 + no = 0;
2016 + else if (c == '\\' && '0' <= *src && *src <= '9')
2017 + no = *src++ - '0';
2018 + else
2019 + no = -1;
2020 +
2021 + if (no < 0) { /* Ordinary character. */
2022 + if (c == '\\' && (*src == '\\' || *src == '&'))
2023 + c = *src++;
2024 + *dst++ = c;
2025 + } else if (prog->startp[no] != NULL && prog->endp[no] != NULL) {
2026 + len = prog->endp[no] - prog->startp[no];
2027 + (void) strncpy(dst, prog->startp[no], len);
2028 + dst += len;
2029 + if (len != 0 && *(dst-1) == '\0') { /* strncpy hit NUL. */
2030 + regerror("damaged match string");
2031 + return;
2032 + }
2033 + }
2034 + }
2035 + *dst++ = '\0';
2036 +}
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