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f7b63901 | 1 | /* $Cambridge: exim/src/src/regex.c,v 1.3 2004/12/17 14:52:44 ph10 Exp $ */ |
8523533c TK |
2 | |
3 | /************************************************* | |
4 | * Exim - an Internet mail transport agent * | |
5 | *************************************************/ | |
6 | ||
7 | /* Copyright (c) Tom Kistner <tom@duncanthrax.net> 2003-???? */ | |
8 | /* License: GPL */ | |
9 | ||
10 | /* Code for matching regular expressions against headers and body. | |
11 | Called from acl.c. */ | |
12 | ||
13 | #include "exim.h" | |
14 | #ifdef WITH_CONTENT_SCAN | |
15 | #include <unistd.h> | |
16 | #include <sys/mman.h> | |
17 | ||
18 | /* Structure to hold a list of Regular expressions */ | |
19 | typedef struct pcre_list { | |
20 | pcre *re; | |
21 | uschar *pcre_text; | |
22 | struct pcre_list *next; | |
23 | } pcre_list; | |
24 | ||
25 | uschar regex_match_string_buffer[1024]; | |
26 | ||
27 | extern FILE *mime_stream; | |
28 | extern uschar *mime_current_boundary; | |
29 | ||
30 | int regex(uschar **listptr) { | |
31 | int sep = 0; | |
32 | uschar *list = *listptr; | |
33 | uschar *regex_string; | |
34 | uschar regex_string_buffer[1024]; | |
f7b63901 | 35 | unsigned long mbox_size; |
8523533c TK |
36 | FILE *mbox_file; |
37 | pcre *re; | |
38 | pcre_list *re_list_head = NULL; | |
39 | pcre_list *re_list_item; | |
40 | const char *pcre_error; | |
41 | int pcre_erroffset; | |
42 | uschar *linebuffer; | |
43 | long f_pos = 0; | |
44 | ||
45 | /* reset expansion variable */ | |
46 | regex_match_string = NULL; | |
47 | ||
48 | if (mime_stream == NULL) { | |
49 | /* We are in the DATA ACL */ | |
50 | mbox_file = spool_mbox(&mbox_size); | |
51 | if (mbox_file == NULL) { | |
52 | /* error while spooling */ | |
53 | log_write(0, LOG_MAIN|LOG_PANIC, | |
54 | "regex acl condition: error while creating mbox spool file"); | |
55 | return DEFER; | |
56 | }; | |
57 | } | |
58 | else { | |
59 | f_pos = ftell(mime_stream); | |
60 | mbox_file = mime_stream; | |
61 | }; | |
62 | ||
63 | /* precompile our regexes */ | |
64 | while ((regex_string = string_nextinlist(&list, &sep, | |
65 | regex_string_buffer, | |
66 | sizeof(regex_string_buffer))) != NULL) { | |
67 | ||
68 | /* parse option */ | |
69 | if ( (strcmpic(regex_string,US"false") == 0) || | |
70 | (Ustrcmp(regex_string,"0") == 0) ) { | |
71 | /* explicitly no matching */ | |
72 | continue; | |
73 | }; | |
74 | ||
75 | /* compile our regular expression */ | |
76 | re = pcre_compile( CS regex_string, | |
77 | 0, | |
78 | &pcre_error, | |
79 | &pcre_erroffset, | |
80 | NULL ); | |
81 | ||
82 | if (re == NULL) { | |
83 | log_write(0, LOG_MAIN, | |
84 | "regex acl condition warning - error in regex '%s': %s at offset %d, skipped.", regex_string, pcre_error, pcre_erroffset); | |
85 | continue; | |
86 | } | |
87 | else { | |
88 | re_list_item = store_get(sizeof(pcre_list)); | |
89 | re_list_item->re = re; | |
90 | re_list_item->pcre_text = string_copy(regex_string); | |
91 | re_list_item->next = re_list_head; | |
92 | re_list_head = re_list_item; | |
93 | }; | |
94 | }; | |
95 | ||
96 | /* no regexes -> nothing to do */ | |
97 | if (re_list_head == NULL) { | |
98 | return FAIL; | |
99 | }; | |
100 | ||
101 | /* match each line against all regexes */ | |
102 | linebuffer = store_get(32767); | |
103 | while (fgets(CS linebuffer, 32767, mbox_file) != NULL) { | |
104 | if ( (mime_stream != NULL) && (mime_current_boundary != NULL) ) { | |
105 | /* check boundary */ | |
106 | if (Ustrncmp(linebuffer,"--",2) == 0) { | |
107 | if (Ustrncmp((linebuffer+2),mime_current_boundary,Ustrlen(mime_current_boundary)) == 0) | |
108 | /* found boundary */ | |
109 | break; | |
110 | }; | |
111 | }; | |
112 | re_list_item = re_list_head; | |
113 | do { | |
114 | /* try matcher on the line */ | |
115 | if (pcre_exec(re_list_item->re, NULL, CS linebuffer, | |
f7b63901 | 116 | (int)Ustrlen(linebuffer), 0, 0, NULL, 0) >= 0) { |
8523533c TK |
117 | Ustrncpy(regex_match_string_buffer, re_list_item->pcre_text, 1023); |
118 | regex_match_string = regex_match_string_buffer; | |
119 | if (mime_stream == NULL) | |
120 | fclose(mbox_file); | |
121 | else { | |
122 | clearerr(mime_stream); | |
123 | fseek(mime_stream,f_pos,SEEK_SET); | |
124 | }; | |
125 | return OK; | |
126 | }; | |
127 | re_list_item = re_list_item->next; | |
128 | } while (re_list_item != NULL); | |
129 | }; | |
130 | ||
131 | if (mime_stream == NULL) | |
132 | fclose(mbox_file); | |
133 | else { | |
134 | clearerr(mime_stream); | |
135 | fseek(mime_stream,f_pos,SEEK_SET); | |
136 | }; | |
137 | ||
138 | /* no matches ... */ | |
139 | return FAIL; | |
140 | } | |
141 | ||
142 | ||
143 | int mime_regex(uschar **listptr) { | |
144 | int sep = 0; | |
145 | uschar *list = *listptr; | |
146 | uschar *regex_string; | |
147 | uschar regex_string_buffer[1024]; | |
148 | pcre *re; | |
149 | pcre_list *re_list_head = NULL; | |
150 | pcre_list *re_list_item; | |
151 | const char *pcre_error; | |
152 | int pcre_erroffset; | |
153 | FILE *f; | |
154 | uschar *mime_subject = NULL; | |
155 | int mime_subject_len = 0; | |
156 | ||
157 | /* reset expansion variable */ | |
158 | regex_match_string = NULL; | |
159 | ||
160 | /* precompile our regexes */ | |
161 | while ((regex_string = string_nextinlist(&list, &sep, | |
162 | regex_string_buffer, | |
163 | sizeof(regex_string_buffer))) != NULL) { | |
164 | ||
165 | /* parse option */ | |
166 | if ( (strcmpic(regex_string,US"false") == 0) || | |
167 | (Ustrcmp(regex_string,"0") == 0) ) { | |
168 | /* explicitly no matching */ | |
169 | continue; | |
170 | }; | |
171 | ||
172 | /* compile our regular expression */ | |
173 | re = pcre_compile( CS regex_string, | |
174 | 0, | |
175 | &pcre_error, | |
176 | &pcre_erroffset, | |
177 | NULL ); | |
178 | ||
179 | if (re == NULL) { | |
180 | log_write(0, LOG_MAIN, | |
181 | "regex acl condition warning - error in regex '%s': %s at offset %d, skipped.", regex_string, pcre_error, pcre_erroffset); | |
182 | continue; | |
183 | } | |
184 | else { | |
185 | re_list_item = store_get(sizeof(pcre_list)); | |
186 | re_list_item->re = re; | |
187 | re_list_item->pcre_text = string_copy(regex_string); | |
188 | re_list_item->next = re_list_head; | |
189 | re_list_head = re_list_item; | |
190 | }; | |
191 | }; | |
192 | ||
193 | /* no regexes -> nothing to do */ | |
194 | if (re_list_head == NULL) { | |
195 | return FAIL; | |
196 | }; | |
197 | ||
198 | /* check if the file is already decoded */ | |
199 | if (mime_decoded_filename == NULL) { | |
200 | uschar *empty = US""; | |
201 | /* no, decode it first */ | |
202 | mime_decode(&empty); | |
203 | if (mime_decoded_filename == NULL) { | |
204 | /* decoding failed */ | |
205 | log_write(0, LOG_MAIN, | |
206 | "mime_regex acl condition warning - could not decode MIME part to file."); | |
207 | return DEFER; | |
208 | }; | |
209 | }; | |
210 | ||
211 | ||
212 | /* open file */ | |
213 | f = fopen(CS mime_decoded_filename, "r"); | |
214 | if (f == NULL) { | |
215 | /* open failed */ | |
216 | log_write(0, LOG_MAIN, | |
217 | "mime_regex acl condition warning - can't open '%s' for reading.", mime_decoded_filename); | |
218 | return DEFER; | |
219 | }; | |
220 | ||
221 | /* get 32k memory */ | |
222 | mime_subject = (uschar *)store_get(32767); | |
223 | ||
224 | /* read max 32k chars from file */ | |
225 | mime_subject_len = fread(mime_subject, 1, 32766, f); | |
226 | ||
227 | re_list_item = re_list_head; | |
228 | do { | |
229 | /* try matcher on the mmapped file */ | |
230 | debug_printf("Matching '%s'\n", re_list_item->pcre_text); | |
231 | if (pcre_exec(re_list_item->re, NULL, CS mime_subject, | |
232 | mime_subject_len, 0, 0, NULL, 0) >= 0) { | |
233 | Ustrncpy(regex_match_string_buffer, re_list_item->pcre_text, 1023); | |
234 | regex_match_string = regex_match_string_buffer; | |
235 | fclose(f); | |
236 | return OK; | |
237 | }; | |
238 | re_list_item = re_list_item->next; | |
239 | } while (re_list_item != NULL); | |
240 | ||
241 | fclose(f); | |
242 | ||
243 | /* no matches ... */ | |
244 | return FAIL; | |
245 | } | |
246 | ||
247 | #endif |