suricata
util-lua-smtp.c
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1 /* Copyright (C) 2014 Open Information Security Foundation
2  *
3  * You can copy, redistribute or modify this Program under the terms of
4  * the GNU General Public License version 2 as published by the Free
5  * Software Foundation.
6  *
7  * This program is distributed in the hope that it will be useful,
8  * but WITHOUT ANY WARRANTY; without even the implied warranty of
9  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
10  * GNU General Public License for more details.
11  *
12  * You should have received a copy of the GNU General Public License
13  * version 2 along with this program; if not, write to the Free Software
14  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
15  * 02110-1301, USA.
16  */
17 
18 /**
19  * \file
20  *
21  * \author casec Bachelors group
22  * \author Lauritz Prag Sømme <lauritz24@me.com>
23  * \author Levi Tobiassen <levi.tobiassen@gmail.com>
24  * \author Stian Hoel Bergseth <stian.bergseth@hig.no>
25  * \author Vinjar Hillestad <vinjar.hillestad@hig.no>
26  */
27 
28 #include "suricata-common.h"
29 
30 #include "debug.h"
31 #include "conf.h"
32 
33 #include "threads.h"
34 #include "threadvars.h"
35 #include "tm-threads.h"
36 #include "output.h"
37 
38 #include "app-layer-smtp.h"
39 
40 #ifdef HAVE_LUA
41 
42 #include <lua.h>
43 #include <lualib.h>
44 
45 #include "util-lua.h"
46 #include "util-lua-common.h"
47 #include "util-lua-smtp.h"
48 #include "util-file.h"
49 
50 /*
51  * \brief internal function used by SMTPGetMimeField
52  *
53  * \param luastate luastate stack to use and push attributes to
54  * \param flow network flow of SMTP packets
55  * \param name name of the attribute to extract from MimeDecField
56  *
57  * \retval 1 if success mimefield found and pushed to stack. Returns error
58  * int and msg pushed to luastate stack if error occurs.
59  */
60 
61 static int GetMimeDecField(lua_State *luastate, Flow *flow, const char *name)
62 {
63  /* extract state from flow */
64  SMTPState *state = (SMTPState *) FlowGetAppState(flow);
65  /* check that state exsists */
66  if(state == NULL) {
67  return LuaCallbackError(luastate, "Internal error: no state in flow");
68  }
69  /* pointer to current transaction in state */
70  SMTPTransaction *smtp_tx = state->curr_tx;
71  if(smtp_tx == NULL) {
72  return LuaCallbackError(luastate, "Transaction ending or not found");
73  }
74  /* pointer to tail of msg list of MimeDecEntitys in current transaction. */
75  MimeDecEntity *mime = smtp_tx->msg_tail;
76  /* check if msg_tail was hit */
77  if(mime == NULL){
78  return LuaCallbackError(luastate, "Internal error: no fields in transaction");
79  }
80  /* extract MIME field based on spesific field name. */
81  MimeDecField *field = MimeDecFindField(mime, name);
82  /* check MIME field */
83  if(field == NULL) {
84  return LuaCallbackError(luastate, "Error: mimefield not found");
85  }
86  /* return extracted field. */
87  if(field->value == NULL || field->value_len == 0){
88  return LuaCallbackError(luastate, "Error, pointer error");
89  }
90 
91  return LuaPushStringBuffer(luastate, field->value, field->value_len);
92 }
93 
94 /**
95  * \brief Function extracts specific MIME field based on argument from luastate
96  * stack then pushing the attribute onto the luastate stack.
97  *
98  * \param luastate luastate stack to pop and push attributes for I/O to lua
99  *
100  * \retval 1 if success mimefield found and pushed to stack. Returns error
101  * int and msg pushed to luastate stack if error occurs.
102  */
103 
104 static int SMTPGetMimeField(lua_State *luastate)
105 {
106  if(!(LuaStateNeedProto(luastate, ALPROTO_SMTP))) {
107  return LuaCallbackError(luastate, "error: protocol not SMTP");
108  }
109  Flow *flow = LuaStateGetFlow(luastate);
110  /* check that flow exist */
111  if(flow == NULL) {
112  return LuaCallbackError(luastate, "Error: no flow found");
113  }
114  const char *name = LuaGetStringArgument(luastate, 1);
115  if (name == NULL)
116  return LuaCallbackError(luastate, "1st argument missing, empty or wrong type");
117 
118  GetMimeDecField(luastate, flow, name);
119 
120  return 1;
121 }
122 
123 /**
124  * \brief Internal function used by SMTPGetMimeList
125  *
126  * \param luastate luastate stack to pop and push attributes for I/O to lua
127  * \param flow network flow of SMTP packets
128  *
129  * \retval 1 if the mimelist table is pushed to luastate stack.
130  * Returns error int and msg pushed to luastate stack if error occurs.
131 */
132 
133 static int GetMimeList(lua_State *luastate, Flow *flow)
134 {
135 
136  SMTPState *state = (SMTPState *) FlowGetAppState(flow);
137  if(state == NULL) {
138  return LuaCallbackError(luastate, "Error: no SMTP state");
139  }
140  /* Create a pointer to the current SMTPtransaction */
141  SMTPTransaction *smtp_tx = state->curr_tx;
142  if(smtp_tx == NULL) {
143  return LuaCallbackError(luastate, "Error: no SMTP transaction found");
144  }
145  /* Create a pointer to the tail of MimeDecEntity list */
146  MimeDecEntity *mime = smtp_tx->msg_tail;
147  if(mime == NULL) {
148  return LuaCallbackError(luastate, "Error: no mime entity found");
149  }
150  MimeDecField *field = mime->field_list;
151  if(field == NULL) {
152  return LuaCallbackError(luastate, "Error: no field_list found");
153  }
154  if(field->name == NULL || field->name_len == 0) {
155  return LuaCallbackError(luastate, "Error: field has no name");
156  }
157  /* Counter of MIME fields found */
158  int num = 1;
159  /* loop trough the list of mimeFields, printing each name found */
160  lua_newtable(luastate);
161  while (field != NULL) {
162  if(field->name != NULL && field->name_len != 0) {
163  lua_pushinteger(luastate,num++);
164  LuaPushStringBuffer(luastate, field->name, field->name_len);
165  lua_settable(luastate,-3);
166  }
167  field = field->next;
168  }
169  return 1;
170 }
171 
172 /**
173  * \brief Lists name and value to all MIME fields which
174  * is included in a SMTP transaction.
175  *
176  * \param luastate luastate stack to pop and push attributes for I/O to lua.
177  *
178  * \retval 1 if the table is pushed to lua.
179  * Returns error int and msg pushed to luastate stack if error occurs
180  *
181  */
182 
183 static int SMTPGetMimeList(lua_State *luastate)
184 {
185  /* Check if right protocol */
186  if(!(LuaStateNeedProto(luastate, ALPROTO_SMTP))) {
187  return LuaCallbackError(luastate, "Error: protocol not SMTP");
188  }
189  /* Extract network flow */
190  Flow *flow = LuaStateGetFlow(luastate);
191  if(flow == NULL) {
192  return LuaCallbackError(luastate, "Error: no flow found");
193  }
194 
195  GetMimeList(luastate, flow);
196 
197  return 1;
198 }
199 
200 /**
201  * \brief internal function used by SMTPGetMailFrom
202  *
203  * \param luastate luastate stack to pop and push attributes for I/O to lua.
204  * \param flow flow to get state for SMTP
205  *
206  * \retval 1 if mailfrom field found.
207  * Retruns error int and msg pushed to luastate stack if error occurs
208  */
209 
210 static int GetMailFrom(lua_State *luastate, Flow *flow)
211 {
212  /* Extract SMTPstate from current flow */
213  SMTPState *state = (SMTPState *) FlowGetAppState(flow);
214 
215  if(state == NULL) {
216  return LuaCallbackError(luastate, "Internal Error: no state");
217  }
218  SMTPTransaction *smtp_tx = state->curr_tx;
219  if(smtp_tx == NULL) {
220  return LuaCallbackError(luastate, "Internal Error: no SMTP transaction");
221  }
222  if(smtp_tx->mail_from == NULL || smtp_tx->mail_from_len == 0) {
223  return LuaCallbackError(luastate, "MailFrom not found");
224  }
225  return LuaPushStringBuffer(luastate, smtp_tx->mail_from, smtp_tx->mail_from_len);
226  /* Returns 1 because we never push more then 1 item to the lua stack */
227 }
228 
229 /**
230  * \brief Extracts mail_from parameter from SMTPState.
231  * Attribute may also be available from mimefields, although there is no
232  * guarantee of it existing as mime.
233  *
234  * \param luastate luastate stack to pop and push attributes for I/O to lua.
235  *
236  * \retval 1 if mailfrom field found.
237  * Retruns error int and msg pushed to luastate stack if error occurs
238  */
239 
240 static int SMTPGetMailFrom(lua_State *luastate)
241 {
242  /* check protocol */
243  if(!(LuaStateNeedProto(luastate, ALPROTO_SMTP))) {
244  return LuaCallbackError(luastate, "Error: protocol not SMTP");
245  }
246  /* Extract flow, with lockhint to check mutexlocking */
247  Flow *flow = LuaStateGetFlow(luastate);
248  if(flow == NULL) {
249  return LuaCallbackError(luastate, "Internal Error: no flow");
250  }
251 
252  GetMailFrom(luastate, flow);
253 
254  return 1;
255 }
256 
257 /**
258  * \brief intern function used by SMTPGetRcpList
259  *
260  * \params luastate luastate stack for internal communication with Lua.
261  * Used to hand over data to the recieveing luascript.
262  *
263  * \retval 1 if the table is pushed to lua.
264  * Returns error int and msg pushed to luastate stack if error occurs
265  */
266 
267 static int GetRcptList(lua_State *luastate, Flow *flow)
268 {
269 
270  SMTPState *state = (SMTPState *) FlowGetAppState(flow);
271  if(state == NULL) {
272  return LuaCallbackError(luastate, "Internal error, no state");
273  }
274 
275  SMTPTransaction *smtp_tx = state->curr_tx;
276  if(smtp_tx == NULL) {
277  return LuaCallbackError(luastate, "No more tx, or tx not found");
278  }
279 
280  /* Create a new table in luastate for rcpt list */
281  lua_newtable(luastate);
282  /* rcpt var for iterator */
283  int u = 1;
284  SMTPString *rcpt;
285 
286  TAILQ_FOREACH(rcpt, &smtp_tx->rcpt_to_list, next) {
287  lua_pushinteger(luastate, u++);
288  LuaPushStringBuffer(luastate, rcpt->str, rcpt->len);
289  lua_settable(luastate, -3);
290  }
291  /* return 1 since we allways push one table to luastate */
292  return 1;
293 }
294 
295 /**
296  * \brief function loops through rcpt-list located in
297  * flow->SMTPState->SMTPTransaction, adding all items to a table.
298  * Then pushing it to the luastate stack.
299  *
300  * \params luastate luastate stack for internal communication with Lua.
301  * Used to hand over data to the recieveing luascript.
302  *
303  * \retval 1 if the table is pushed to lua.
304  * Returns error int and msg pushed to luastate stack if error occurs
305  */
306 
307 static int SMTPGetRcptList(lua_State *luastate)
308 {
309  /* check protocol */
310  if(!(LuaStateNeedProto(luastate, ALPROTO_SMTP))) {
311  return LuaCallbackError(luastate, "Error: protocol not SMTP");
312  }
313  /* Extract flow, with lockhint to check mutexlocking */
314  Flow *flow = LuaStateGetFlow(luastate);
315  if(flow == NULL) {
316  return LuaCallbackError(luastate, "Internal error: no flow");
317  }
318 
319  GetRcptList(luastate, flow);
320 
321  /* return 1 since we allways push one table to luastate */
322  return 1;
323 }
324 
325 int LuaRegisterSmtpFunctions(lua_State *luastate)
326 {
327 
328  lua_pushcfunction(luastate, SMTPGetMimeField);
329  lua_setglobal(luastate, "SMTPGetMimeField");
330 
331  lua_pushcfunction(luastate, SMTPGetMimeList);
332  lua_setglobal(luastate, "SMTPGetMimeList");
333 
334  lua_pushcfunction(luastate, SMTPGetMailFrom);
335  lua_setglobal(luastate, "SMTPGetMailFrom");
336 
337  lua_pushcfunction(luastate, SMTPGetRcptList);
338  lua_setglobal(luastate, "SMTPGetRcptList");
339 
340  return 0;
341 }
342 
343 #endif /* HAVE_LUA */
uint8_t * mail_from
MimeDecField * field_list
#define TAILQ_FOREACH(var, head, field)
Definition: queue.h:350
struct HtpBodyChunk_ * next
uint16_t mail_from_len
MimeDecEntity * msg_tail
struct MimeDecField * next
uint16_t len
MimeDecField * MimeDecFindField(const MimeDecEntity *entity, const char *name)
Searches for a header field with the specified name.
This represents the MIME Entity (or also top level message) in a child-sibling tree.
uint32_t value_len
SMTPTransaction * curr_tx
uint8_t * str
void * FlowGetAppState(const Flow *f)
Definition: flow.c:1065
This represents a header field name and associated value.
Flow data structure.
Definition: flow.h:324