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#include "common.h"
2 
#include "send.h"
3 
 
4 
extern int debug;
5 
 
6 
/*
7 
 *	Routines for dealing with the rewrite rules.
8 
 */
9 
 
10 
/* globals */
11 
typedef struct rule rule;
12 
 
13 
#define NSUBEXP 10
14 
struct rule {
15 
	String *matchre;	/* address match */
16 
	String *repl1;		/* first replacement String */
17 
	String *repl2;		/* second replacement String */
18 
	d_status type;		/* type of rule */
19 
	Reprog *program;
20 
	Resub subexp[NSUBEXP];
21 
	rule *next;
22 
};
23 
static rule *rulep;
24 
static rule *rlastp;
25 
 
26 
/* predeclared */
27 
static String *substitute(String *, Resub *, message *);
28 
static rule *findrule(String *, int);
29 
 
30 
 
31 
/*
32 
 *  Get the next token from `line'.  The symbol `\l' is replaced by
33 
 *  the name of the local system.
34 
 */
35 
extern String *
36 
rule_parse(String *line, char *system, int *backl)
37 
{
38 
	String *token;
39 
	String *expanded;
40 
	char *cp;
41 
 
42 
	token = s_parse(line, 0);
43 
	if(token == 0)
44 
		return(token);
45 
	if(strchr(s_to_c(token), '\\')==0)
46 
		return(token);
47 
	expanded = s_new();
48 
	for(cp = s_to_c(token); *cp; cp++) {
49 
		if(*cp == '\\') switch(*++cp) {
50 
		case 'l':
51 
			s_append(expanded, system);
52 
			*backl = 1;
53 
			break;
54 
		case '\\':
55 
			s_putc(expanded, '\\');
56 
			break;
57 
		default:
58 
			s_putc(expanded, '\\');
59 
			s_putc(expanded, *cp);
60 
			break;
61 
		} else
62 
			s_putc(expanded, *cp);
63 
	}
64 
	s_free(token);
65 
	s_terminate(expanded);
66 
	return(expanded);
67 
}
68 
 
69 
static int
70 
getrule(String *line, String *type, char *system)
71 
{
72 
	rule	*rp;
73 
	String	*re;
74 
	int	backl;
75 
 
76 
	backl = 0;
77 
 
78 
	/* get a rule */
79 
	re = rule_parse(s_restart(line), system, &backl);
80 
	if(re == 0)
81 
		return 0;
82 
	rp = (rule *)malloc(sizeof(rule));
83 
	if(rp == 0) {
84 
		perror("getrules:");
85 
		exit(1);
86 
	}
87 
	rp->next = 0;
88 
	s_tolower(re);
89 
	rp->matchre = s_new();
90 
	s_append(rp->matchre, s_to_c(re));
91 
	s_restart(rp->matchre);
92 
	s_free(re);
93 
	s_parse(line, s_restart(type));
94 
	rp->repl1 = rule_parse(line, system, &backl);
95 
	rp->repl2 = rule_parse(line, system, &backl);
96 
	rp->program = 0;
97 
	if(strcmp(s_to_c(type), "|") == 0)
98 
		rp->type = d_pipe;
99 
	else if(strcmp(s_to_c(type), ">>") == 0)
100 
		rp->type = d_cat;
101 
	else if(strcmp(s_to_c(type), "alias") == 0)
102 
		rp->type = d_alias;
103 
	else if(strcmp(s_to_c(type), "translate") == 0)
104 
		rp->type = d_translate;
105 
	else if(strcmp(s_to_c(type), "auth") == 0)
106 
		rp->type = d_auth;
107 
	else {
108 
		s_free(rp->matchre);
109 
		s_free(rp->repl1);
110 
		s_free(rp->repl2);
111 
		free((char *)rp);
112 
		fprint(2,"illegal rewrite rule: %s\n", s_to_c(line));
113 
		return 0;
114 
	}
115 
	if(rulep == 0)
116 
		rulep = rlastp = rp;
117 
	else
118 
		rlastp = rlastp->next = rp;
119 
	return backl;
120 
}
121 
 
122 
/*
123 
 *  rules are of the form:
124 
 *	<reg exp> <String> <repl exp> [<repl exp>]
125 
 */
126 
extern int
127 
getrules(void)
128 
{
129 
	Biobuf	*rfp;
130 
	String	*line;
131 
	String	*type;
132 
	String	*file;
133 
 
134 
	file = abspath("rewrite", UPASLIB, (String *)0);
135 
	rfp = sysopen(s_to_c(file), "r", 0);
136 
	if(rfp == 0) {
137 
		rulep = 0;
138 
		return -1;
139 
	}
140 
	rlastp = 0;
141 
	line = s_new();
142 
	type = s_new();
143 
	while(s_getline(rfp, s_restart(line)))
144 
		if(getrule(line, type, thissys) && altthissys)
145 
			getrule(s_restart(line), type, altthissys);
146 
	s_free(type);
147 
	s_free(line);
148 
	s_free(file);
149 
	sysclose(rfp);
150 
	return 0;
151 
}
152 
 
153 
/* look up a matching rule */
154 
static rule *
155 
findrule(String *addrp, int authorized)
156 
{
157 
	rule *rp;
158 
	static rule defaultrule;
159 
 
160 
	if(rulep == 0)
161 
		return &defaultrule;
162 
	for (rp = rulep; rp != 0; rp = rp->next) {
163 
		if(rp->type==d_auth && authorized)
164 
			continue;
165 
		if(rp->program == 0)
166 
			rp->program = regcomp(rp->matchre->base);
167 
		if(rp->program == 0)
168 
			continue;
169 
		memset(rp->subexp, 0, sizeof(rp->subexp));
170 
		if(debug)
171 
			fprint(2, "matching %s against %s\n", s_to_c(addrp),
172 
				rp->matchre->base);
173 
		if(regexec(rp->program, s_to_c(addrp), rp->subexp, NSUBEXP))
174 
		if(s_to_c(addrp) == rp->subexp[0].sp)
175 
		if((s_to_c(addrp) + strlen(s_to_c(addrp))) == rp->subexp[0].ep)
176 
			return rp;
177 
	}
178 
	return 0;
179 
}
180 
 
181 
/*  Transforms the address into a command.
182 
 *  Returns:	-1 ifaddress not matched by reules
183 
 *		 0 ifaddress matched and ok to forward
184 
 *		 1 ifaddress matched and not ok to forward
185 
 */
186 
extern int
187 
rewrite(dest *dp, message *mp)
188 
{
189 
	rule *rp;		/* rewriting rule */
190 
	String *lower;		/* lower case version of destination */
191 
 
192 
	/*
193 
	 *  Rewrite the address.  Matching is case insensitive.
194 
	 */
195 
	lower = s_clone(dp->addr);
196 
	s_tolower(s_restart(lower));
197 
	rp = findrule(lower, dp->authorized);
198 
	if(rp == 0){
199 
		s_free(lower);
200 
		return -1;
201 
	}
202 
	strcpy(s_to_c(lower), s_to_c(dp->addr));
203 
	dp->repl1 = substitute(rp->repl1, rp->subexp, mp);
204 
	dp->repl2 = substitute(rp->repl2, rp->subexp, mp);
205 
	dp->status = rp->type;
206 
	if(debug){
207 
		fprint(2, "\t->");
208 
		if(dp->repl1)
209 
			fprint(2, "%s", s_to_c(dp->repl1));
210 
		if(dp->repl2)
211 
			fprint(2, "%s", s_to_c(dp->repl2));
212 
		fprint(2, "\n");
213 
	}
214 
	s_free(lower);
215 
	return 0;
216 
}
217 
 
218 
static String *
219 
substitute(String *source, Resub *subexp, message *mp)
220 
{
221 
	int i;
222 
	char *s;
223 
	char *sp;
224 
	String *stp;
225 
 
226 
	if(source == 0)
227 
		return 0;
228 
	sp = s_to_c(source);
229 
 
230 
	/* someplace to put it */
231 
	stp = s_new();
232 
 
233 
	/* do the substitution */
234 
	while (*sp != '\0') {
235 
		if(*sp == '\\') {
236 
			switch (*++sp) {
237 
			case '0': case '1': case '2': case '3': case '4':
238 
			case '5': case '6': case '7': case '8': case '9':
239 
				i = *sp-'0';
240 
				if(subexp[i].sp != 0)
241 
					for (s = subexp[i].sp;
242 
					     s < subexp[i].ep;
243 
					     s++)
244 
						s_putc(stp, *s);
245 
				break;
246 
			case '\\':
247 
				s_putc(stp, '\\');
248 
				break;
249 
			case '\0':
250 
				sp--;
251 
				break;
252 
			case 's':
253 
				for(s = s_to_c(mp->replyaddr); *s; s++)
254 
					s_putc(stp, *s);
255 
				break;
256 
			case 'p':
257 
				if(mp->bulk)
258 
					s = "bulk";
259 
				else
260 
					s = "normal";
261 
				for(;*s; s++)
262 
					s_putc(stp, *s);
263 
				break;
264 
			default:
265 
				s_putc(stp, *sp);
266 
				break;
267 
			}
268 
		} else if(*sp == '&') {
269 
			if(subexp[0].sp != 0)
270 
				for (s = subexp[0].sp;
271 
				     s < subexp[0].ep; s++)
272 
					s_putc(stp, *s);
273 
		} else
274 
			s_putc(stp, *sp);
275 
		sp++;
276 
	}
277 
	s_terminate(stp);
278 
 
279 
	return s_restart(stp);
280 
}
281 
 
282 
extern void
283 
regerror(char* s)
284 
{
285 
	fprint(2, "rewrite: %s\n", s);
286 
	/* make sure the message is seen locally */
287 
	syslog(0, "mail", "regexp error in rewrite: %s", s);
288 
}
289 
 
290 
extern void
291 
dumprules(void)
292 
{
293 
	rule *rp;
294 
 
295 
	for (rp = rulep; rp != 0; rp = rp->next) {
296 
		fprint(2, "'%s'", rp->matchre->base);
297 
		switch (rp->type) {
298 
		case d_pipe:
299 
			fprint(2, " |");
300 
			break;
301 
		case d_cat:
302 
			fprint(2, " >>");
303 
			break;
304 
		case d_alias:
305 
			fprint(2, " alias");
306 
			break;
307 
		case d_translate:
308 
			fprint(2, " translate");
309 
			break;
310 
		default:
311 
			fprint(2, " UNKNOWN");
312 
			break;
313 
		}
314 
		fprint(2, " '%s'", rp->repl1 ? rp->repl1->base:"...");
315 
		fprint(2, " '%s'\n", rp->repl2 ? rp->repl2->base:"...");
316 
	}
317 
}
318