2 * iwinfo - Wireless Information Library - Linux Wireless Extension Backend
4 * Copyright (C) 2009 Jo-Philipp Wich <xm@subsignal.org>
6 * The iwinfo library is free software: you can redistribute it and/or
7 * modify it under the terms of the GNU General Public License version 2
8 * as published by the Free Software Foundation.
10 * The iwinfo library is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
13 * See the GNU General Public License for more details.
15 * You should have received a copy of the GNU General Public License along
16 * with the iwinfo library. If not, see http://www.gnu.org/licenses/.
18 * Parts of this code are derived from the Linux wireless tools, iwlib.c,
19 * iwlist.c and iwconfig.c in particular.
23 #include "iwinfo_wext_scan.h"
26 static int ioctl_socket = -1;
28 static int wext_ioctl(const char *ifname, int cmd, struct iwreq *wrq)
31 if( ioctl_socket == -1 )
32 ioctl_socket = socket(AF_INET, SOCK_DGRAM, 0);
34 strncpy(wrq->ifr_name, ifname, IFNAMSIZ);
35 return ioctl(ioctl_socket, cmd, wrq);
38 static double wext_freq2float(const struct iw_freq *in)
41 double res = (double) in->m;
42 for(i = 0; i < in->e; i++) res *= 10;
46 static int wext_extract_event(struct stream_descr *stream, struct iw_event *iwe)
48 const struct iw_ioctl_description *descr = NULL;
50 unsigned int event_len = 1;
52 unsigned cmd_index; /* *MUST* be unsigned */
54 /* Check for end of stream */
55 if((stream->current + IW_EV_LCP_PK_LEN) > stream->end)
58 /* Extract the event header (to get the event id).
59 * Note : the event may be unaligned, therefore copy... */
60 memcpy((char *) iwe, stream->current, IW_EV_LCP_PK_LEN);
62 /* Check invalid events */
63 if(iwe->len <= IW_EV_LCP_PK_LEN)
66 /* Get the type and length of that event */
67 if(iwe->cmd <= SIOCIWLAST)
69 cmd_index = iwe->cmd - SIOCIWFIRST;
70 if(cmd_index < standard_ioctl_num)
71 descr = &(standard_ioctl_descr[cmd_index]);
75 cmd_index = iwe->cmd - IWEVFIRST;
76 if(cmd_index < standard_event_num)
77 descr = &(standard_event_descr[cmd_index]);
81 event_type = descr->header_type;
83 /* Unknown events -> event_type=0 => IW_EV_LCP_PK_LEN */
84 event_len = event_type_size[event_type];
86 /* Check if we know about this event */
87 if(event_len <= IW_EV_LCP_PK_LEN)
89 /* Skip to next event */
90 stream->current += iwe->len;
94 event_len -= IW_EV_LCP_PK_LEN;
96 /* Set pointer on data */
97 if(stream->value != NULL)
98 pointer = stream->value; /* Next value in event */
100 pointer = stream->current + IW_EV_LCP_PK_LEN; /* First value in event */
102 /* Copy the rest of the event (at least, fixed part) */
103 if((pointer + event_len) > stream->end)
105 /* Go to next event */
106 stream->current += iwe->len;
110 /* Fixup for WE-19 and later : pointer no longer in the stream */
111 /* Beware of alignement. Dest has local alignement, not packed */
112 if( event_type == IW_HEADER_TYPE_POINT )
113 memcpy((char *) iwe + IW_EV_LCP_LEN + IW_EV_POINT_OFF, pointer, event_len);
115 memcpy((char *) iwe + IW_EV_LCP_LEN, pointer, event_len);
117 /* Skip event in the stream */
118 pointer += event_len;
120 /* Special processing for iw_point events */
121 if(event_type == IW_HEADER_TYPE_POINT)
123 /* Check the length of the payload */
124 unsigned int extra_len = iwe->len - (event_len + IW_EV_LCP_PK_LEN);
127 /* Set pointer on variable part (warning : non aligned) */
128 iwe->u.data.pointer = pointer;
130 /* Check that we have a descriptor for the command */
132 /* Can't check payload -> unsafe... */
133 iwe->u.data.pointer = NULL; /* Discard paylod */
136 /* Those checks are actually pretty hard to trigger,
137 * because of the checks done in the kernel... */
139 unsigned int token_len = iwe->u.data.length * descr->token_size;
141 /* Ugly fixup for alignement issues.
142 * If the kernel is 64 bits and userspace 32 bits,
143 * we have an extra 4+4 bytes.
144 * Fixing that in the kernel would break 64 bits userspace. */
145 if((token_len != extra_len) && (extra_len >= 4))
147 uint16_t alt_dlen = *((uint16_t *) pointer);
148 unsigned int alt_token_len = alt_dlen * descr->token_size;
149 if((alt_token_len + 8) == extra_len)
151 /* Ok, let's redo everything */
152 pointer -= event_len;
154 /* Dest has local alignement, not packed */
155 memcpy((char *) iwe + IW_EV_LCP_LEN + IW_EV_POINT_OFF, pointer, event_len);
156 pointer += event_len + 4;
157 iwe->u.data.pointer = pointer;
158 token_len = alt_token_len;
162 /* Discard bogus events which advertise more tokens than
163 * what they carry... */
164 if(token_len > extra_len)
165 iwe->u.data.pointer = NULL; /* Discard paylod */
167 /* Check that the advertised token size is not going to
168 * produce buffer overflow to our caller... */
169 if((iwe->u.data.length > descr->max_tokens)
170 && !(descr->flags & IW_DESCR_FLAG_NOMAX))
171 iwe->u.data.pointer = NULL; /* Discard paylod */
173 /* Same for underflows... */
174 if(iwe->u.data.length < descr->min_tokens)
175 iwe->u.data.pointer = NULL; /* Discard paylod */
180 iwe->u.data.pointer = NULL;
182 /* Go to next event */
183 stream->current += iwe->len;
187 /* Ugly fixup for alignement issues.
188 * If the kernel is 64 bits and userspace 32 bits,
189 * we have an extra 4 bytes.
190 * Fixing that in the kernel would break 64 bits userspace. */
191 if((stream->value == NULL)
192 && ((((iwe->len - IW_EV_LCP_PK_LEN) % event_len) == 4)
193 || ((iwe->len == 12) && ((event_type == IW_HEADER_TYPE_UINT) ||
194 (event_type == IW_HEADER_TYPE_QUAL))) ))
196 pointer -= event_len;
198 /* Beware of alignement. Dest has local alignement, not packed */
199 memcpy((char *) iwe + IW_EV_LCP_LEN, pointer, event_len);
200 pointer += event_len;
203 /* Is there more value in the event ? */
204 if((pointer + event_len) <= (stream->current + iwe->len))
205 /* Go to next value */
206 stream->value = pointer;
209 /* Go to next event */
210 stream->value = NULL;
211 stream->current += iwe->len;
218 static inline void wext_fill_wpa(unsigned char *iebuf, int buflen, struct iwinfo_scanlist_entry *e)
220 int ielen = iebuf[1] + 2;
221 int offset = 2; /* Skip the IE id, and the length. */
222 unsigned char wpa1_oui[3] = {0x00, 0x50, 0xf2};
223 unsigned char wpa2_oui[3] = {0x00, 0x0f, 0xac};
224 unsigned char *wpa_oui;
228 int wpa1 = 0, wpa2 = 0;
231 struct iwinfo_crypto_entry *ce = &e->crypto;
236 //memset(&e->crypto, 0, sizeof(struct iwinfo_crypto_entry));
243 case 0x30: /* WPA2 */
244 /* Check if we have enough data */
251 case 0xdd: /* WPA or else */
253 /* Not all IEs that start with 0xdd are WPA.
254 * * So check that the OUI is valid. */
255 if((ielen < 8) || ((memcmp(&iebuf[offset], wpa_oui, 3) != 0)
256 && (iebuf[offset+3] == 0x01)))
266 /* Pick version number (little endian) */
267 ver = iebuf[offset] | (iebuf[offset + 1] << 8);
276 if( wpa1 && (ce->wpa_version == 2) )
278 else if( wpa2 && (ce->wpa_version == 1) )
280 else if( wpa1 && !ce->wpa_version )
282 else if( wpa2 && !ce->wpa_version )
285 if(ielen < (offset + 4))
287 ce->group_ciphers[2] = 1; /* TKIP */
291 if(memcmp(&iebuf[offset], wpa_oui, 3) != 0)
292 ce->group_ciphers[7] = 1; /* Proprietary */
294 ce->group_ciphers[iebuf[offset+3]] = 1;
298 if(ielen < (offset + 2))
300 ce->pair_ciphers[2] = 1; /* TKIP */
304 /* Otherwise, we have some number of pairwise ciphers. */
305 cnt = iebuf[offset] | (iebuf[offset + 1] << 8);
308 if(ielen < (offset + 4*cnt))
312 for(i = 0; i < cnt; i++)
314 if(memcmp(&iebuf[offset], wpa_oui, 3) != 0)
315 ce->pair_ciphers[7] = 1; /* Proprietary */
316 else if(iebuf[offset+3] <= IW_IE_CYPHER_NUM)
317 ce->pair_ciphers[iebuf[offset+3]] = 1;
319 // ce->pair_ciphers[ce->pair_cipher_num++] = 255; /* Unknown */
324 /* Check if we are done */
325 if(ielen < (offset + 2))
328 /* Now, we have authentication suites. */
329 cnt = iebuf[offset] | (iebuf[offset + 1] << 8);
333 if(ielen < (offset + 4*cnt))
336 for(i = 0; i < cnt; i++)
338 if(memcmp(&iebuf[offset], wpa_oui, 3) != 0)
339 ce->auth_suites[7] = 1; /* Proprietary */
340 else if(iebuf[offset+3] <= IW_IE_KEY_MGMT_NUM)
341 ce->auth_suites[iebuf[offset+3]] = 1;
343 // ce->auth_suites[ce->auth_suite_num++] = 255; /* Unknown */
350 static inline int wext_fill_entry(struct stream_descr *stream, struct iw_event *event,
351 struct iw_range *iw_range, int has_range, struct iwinfo_scanlist_entry *e)
356 /* Now, let's decode the event */
360 memcpy(e->mac, &event->u.ap_addr.sa_data, 6);
364 if( event->u.freq.m >= 1000 )
366 freq = wext_freq2float(&(event->u.freq));
368 for(i = 0; i < iw_range->num_frequency; i++)
370 if( wext_freq2float(&iw_range->freq[i]) == freq )
372 e->channel = iw_range->freq[i].i;
379 e->channel = event->u.freq.m;
385 switch(event->u.mode)
388 sprintf((char *) e->mode, "Ad-Hoc");
392 sprintf((char *) e->mode, "Master");
396 sprintf((char *) e->mode, "Unknown");
402 if( event->u.essid.pointer && event->u.essid.length && event->u.essid.flags )
403 memcpy(e->ssid, event->u.essid.pointer, event->u.essid.length);
408 e->crypto.enabled = !(event->u.data.flags & IW_ENCODE_DISABLED);
413 if(state->val_index == 0)
415 lua_pushstring(L, "bitrates");
418 //iw_print_bitrate(buffer, sizeof(buffer), event->u.bitrate.value);
419 snprintf(buffer, sizeof(buffer), "%d", event->u.bitrate.value);
420 lua_pushinteger(L, state->val_index + 1);
421 lua_pushstring(L, buffer);
424 /* Check for termination */
425 if(stream->value == NULL)
428 state->val_index = 0;
436 while(i <= (event->u.data.length - 2))
438 switch(((unsigned char *)event->u.data.pointer)[i])
440 case 0xdd: /* WPA1 (and other) */
441 case 0x30: /* WPA2 */
442 wext_fill_wpa((unsigned char *)event->u.data.pointer + i,
443 event->u.data.length, e);
448 i += ((unsigned char *)event->u.data.pointer)[i+1] + 2;
458 int wext_get_scanlist(const char *ifname, char *buf, int *len)
461 struct iw_scan_req scanopt; /* Options for 'set' */
462 //int scanflags = 0; /* Flags for scan */
463 unsigned char *buffer = NULL; /* Results */
464 int buflen = IW_SCAN_MAX_DATA; /* Min for compat WE<17 */
465 struct iw_range range;
467 struct timeval tv; /* Select timeout */
468 int timeout = 15000000; /* 15s */
471 struct iwinfo_scanlist_entry e;
474 wrq.u.data.pointer = (caddr_t) ⦥
475 wrq.u.data.length = sizeof(struct iw_range);
476 wrq.u.data.flags = 0;
478 if( wext_ioctl(ifname, SIOCGIWRANGE, &wrq) >= 0 )
480 /* Init timeout value -> 250ms between set and first get */
484 /* Clean up set args */
485 memset(&scanopt, 0, sizeof(scanopt));
487 wrq.u.data.pointer = NULL;
488 wrq.u.data.flags = 0;
489 wrq.u.data.length = 0;
491 /* Initiate Scanning */
492 if( wext_ioctl(ifname, SIOCSIWSCAN, &wrq) >= 0 )
494 timeout -= tv.tv_usec;
499 fd_set rfds; /* File descriptors for select */
500 int last_fd; /* Last fd */
503 /* Guess what ? We must re-generate rfds each time */
506 /* In here, add the rtnetlink fd in the list */
508 /* Wait until something happens */
509 ret = select(last_fd + 1, &rfds, NULL, NULL, &tv);
511 /* Check if there was an error */
514 if(errno == EAGAIN || errno == EINTR)
520 /* Check if there was a timeout */
523 unsigned char *newbuf;
526 /* (Re)allocate the buffer - realloc(NULL, len) == malloc(len) */
527 newbuf = realloc(buffer, buflen);
538 /* Try to read the results */
539 wrq.u.data.pointer = buffer;
540 wrq.u.data.flags = 0;
541 wrq.u.data.length = buflen;
543 if( wext_ioctl(ifname, SIOCGIWSCAN, &wrq) )
545 /* Check if buffer was too small (WE-17 only) */
546 if((errno == E2BIG) && (range.we_version_compiled > 16))
548 /* Some driver may return very large scan results, either
549 * because there are many cells, or because they have many
550 * large elements in cells (like IWEVCUSTOM). Most will
551 * only need the regular sized buffer. We now use a dynamic
552 * allocation of the buffer to satisfy everybody. Of course,
553 * as we don't know in advance the size of the array, we try
554 * various increasing sizes. Jean II */
556 /* Check if the driver gave us any hints. */
557 if(wrq.u.data.length > buflen)
558 buflen = wrq.u.data.length;
566 /* Check if results not available yet */
569 /* Restart timer for only 100ms*/
572 timeout -= tv.tv_usec;
575 continue; /* Try again later */
583 /* We have the results, go to process them */
589 if( wrq.u.data.length )
592 struct stream_descr stream;
596 memset(&stream, 0, sizeof(stream));
597 stream.current = (char *)buffer;
598 stream.end = (char *)buffer + wrq.u.data.length;
602 /* Extract an event and print it */
603 ret = wext_extract_event(&stream, &iwe);
607 if( (iwe.cmd == SIOCGIWAP) || (ret == 0) )
613 else if( (_len + sizeof(struct iwinfo_scanlist_entry)) <= IWINFO_BUFSIZE )
615 memcpy(&buf[_len], &e, sizeof(struct iwinfo_scanlist_entry));
616 _len += sizeof(struct iwinfo_scanlist_entry);
620 /* we exceed the callers buffer size, abort here ... */
624 memset(&e, 0, sizeof(struct iwinfo_scanlist_entry));
627 wext_fill_entry(&stream, &iwe, &range, has_range, &e);