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authorJonathan McCrohan <jmccrohan@gmail.com>2012-02-05 19:04:33 +0000
committerJonathan McCrohan <jmccrohan@gmail.com>2012-02-05 19:04:33 +0000
commitf3410da7f0bd208a5f2d792131b215454e782e93 (patch)
tree6e79c9acde383b91f5f21eb3a72f33e9c7fbbfce /iw_scan.c
parent03dfbc2efa31d3c4fd7e576111883ea488e3e179 (diff)
downloadwavemon-f3410da7f0bd208a5f2d792131b215454e782e93.tar.gz
Imported Upstream version 0.7.3upstream/0.7.3
Diffstat (limited to '')
-rw-r--r--iw_scan.c671
1 files changed, 671 insertions, 0 deletions
diff --git a/iw_scan.c b/iw_scan.c
new file mode 100644
index 0000000..e055acb
--- /dev/null
+++ b/iw_scan.c
@@ -0,0 +1,671 @@
+/*
+ * Auxiliary declarations and functions imported from iwlib in order to
+ * process and parse scan events. This code is copied with little change
+ * from wireless tools 30. It remains here until the wext code will be
+ * replaced by corresponding netlink calls.
+ */
+#include "iw_if.h"
+
+#define MAX_SCAN_WAIT 10000 /* maximum milliseconds spent waiting */
+
+/*
+ * Meta-data about all the additional standard Wireless Extension events
+ * we know about.
+ */
+/* Type of headers we know about (basically union iwreq_data) */
+#define IW_HEADER_TYPE_NULL 0 /* Not available */
+#define IW_HEADER_TYPE_CHAR 2 /* char [IFNAMSIZ] */
+#define IW_HEADER_TYPE_UINT 4 /* __u32 */
+#define IW_HEADER_TYPE_FREQ 5 /* struct iw_freq */
+#define IW_HEADER_TYPE_ADDR 6 /* struct sockaddr */
+#define IW_HEADER_TYPE_POINT 8 /* struct iw_point */
+#define IW_HEADER_TYPE_PARAM 9 /* struct iw_param */
+#define IW_HEADER_TYPE_QUAL 10 /* struct iw_quality */
+
+/* Size (in bytes) of various events */
+static const int event_type_size[] = {
+ [IW_HEADER_TYPE_NULL] = IW_EV_LCP_PK_LEN,
+ [IW_HEADER_TYPE_CHAR] = IW_EV_CHAR_PK_LEN,
+ [IW_HEADER_TYPE_UINT] = IW_EV_UINT_PK_LEN,
+ [IW_HEADER_TYPE_FREQ] = IW_EV_FREQ_PK_LEN,
+ [IW_HEADER_TYPE_ADDR] = IW_EV_ADDR_PK_LEN,
+ /*
+ * Fix IW_EV_POINT_PK_LEN: some wireless.h versions define this
+ * erroneously as IW_EV_LCP_LEN + 4 (e.g. ESSID will disappear).
+ * The value below is from wireless tools 30.
+ */
+ [IW_HEADER_TYPE_POINT] = IW_EV_LCP_PK_LEN + 4,
+ [IW_HEADER_TYPE_PARAM] = IW_EV_PARAM_PK_LEN,
+ [IW_HEADER_TYPE_QUAL] = IW_EV_QUAL_PK_LEN
+};
+
+/* Handling flags */
+#define IW_DESCR_FLAG_NONE 0x0000 /* Obvious */
+/* Wrapper level flags */
+#define IW_DESCR_FLAG_DUMP 0x0001 /* Not part of the dump command */
+#define IW_DESCR_FLAG_EVENT 0x0002 /* Generate an event on SET */
+#define IW_DESCR_FLAG_RESTRICT 0x0004 /* GET : request is ROOT only */
+ /* SET : Omit payload from generated iwevent */
+#define IW_DESCR_FLAG_NOMAX 0x0008 /* GET : no limit on request size */
+/* Driver level flags */
+#define IW_DESCR_FLAG_WAIT 0x0100 /* Wait for driver event */
+
+struct iw_ioctl_description {
+ __u8 header_type; /* NULL, iw_point or other */
+ __u8 token_type; /* Future */
+ __u16 token_size; /* Granularity of payload */
+ __u16 min_tokens; /* Min acceptable token number */
+ __u16 max_tokens; /* Max acceptable token number */
+ __u32 flags; /* Special handling of the request */
+};
+
+/*
+ * Meta-data about all the standard Wireless Extension request we
+ * know about.
+ */
+static const struct iw_ioctl_description standard_ioctl_descr[] = {
+ [SIOCSIWCOMMIT - SIOCIWFIRST] = {
+ .header_type = IW_HEADER_TYPE_NULL,
+ },
+ [SIOCGIWNAME - SIOCIWFIRST] = {
+ .header_type = IW_HEADER_TYPE_CHAR,
+ .flags = IW_DESCR_FLAG_DUMP,
+ },
+ [SIOCSIWNWID - SIOCIWFIRST] = {
+ .header_type = IW_HEADER_TYPE_PARAM,
+ .flags = IW_DESCR_FLAG_EVENT,
+ },
+ [SIOCGIWNWID - SIOCIWFIRST] = {
+ .header_type = IW_HEADER_TYPE_PARAM,
+ .flags = IW_DESCR_FLAG_DUMP,
+ },
+ [SIOCSIWFREQ - SIOCIWFIRST] = {
+ .header_type = IW_HEADER_TYPE_FREQ,
+ .flags = IW_DESCR_FLAG_EVENT,
+ },
+ [SIOCGIWFREQ - SIOCIWFIRST] = {
+ .header_type = IW_HEADER_TYPE_FREQ,
+ .flags = IW_DESCR_FLAG_DUMP,
+ },
+ [SIOCSIWMODE - SIOCIWFIRST] = {
+ .header_type = IW_HEADER_TYPE_UINT,
+ .flags = IW_DESCR_FLAG_EVENT,
+ },
+ [SIOCGIWMODE - SIOCIWFIRST] = {
+ .header_type = IW_HEADER_TYPE_UINT,
+ .flags = IW_DESCR_FLAG_DUMP,
+ },
+ [SIOCSIWSENS - SIOCIWFIRST] = {
+ .header_type = IW_HEADER_TYPE_PARAM,
+ },
+ [SIOCGIWSENS - SIOCIWFIRST] = {
+ .header_type = IW_HEADER_TYPE_PARAM,
+ },
+ [SIOCSIWRANGE - SIOCIWFIRST] = {
+ .header_type = IW_HEADER_TYPE_NULL,
+ },
+ [SIOCGIWRANGE - SIOCIWFIRST] = {
+ .header_type = IW_HEADER_TYPE_POINT,
+ .token_size = 1,
+ .max_tokens = sizeof(struct iw_range),
+ .flags = IW_DESCR_FLAG_DUMP,
+ },
+ [SIOCSIWPRIV - SIOCIWFIRST] = {
+ .header_type = IW_HEADER_TYPE_NULL,
+ },
+ [SIOCGIWPRIV - SIOCIWFIRST] = { /* (handled directly by us) */
+ .header_type = IW_HEADER_TYPE_NULL,
+ },
+ [SIOCSIWSTATS - SIOCIWFIRST] = {
+ .header_type = IW_HEADER_TYPE_NULL,
+ },
+ [SIOCGIWSTATS - SIOCIWFIRST] = { /* (handled directly by us) */
+ .header_type = IW_HEADER_TYPE_NULL,
+ .flags = IW_DESCR_FLAG_DUMP,
+ },
+ [SIOCSIWSPY - SIOCIWFIRST] = {
+ .header_type = IW_HEADER_TYPE_POINT,
+ .token_size = sizeof(struct sockaddr),
+ .max_tokens = IW_MAX_SPY,
+ },
+ [SIOCGIWSPY - SIOCIWFIRST] = {
+ .header_type = IW_HEADER_TYPE_POINT,
+ .token_size = sizeof(struct sockaddr) +
+ sizeof(struct iw_quality),
+ .max_tokens = IW_MAX_SPY,
+ },
+ [SIOCSIWTHRSPY - SIOCIWFIRST] = {
+ .header_type = IW_HEADER_TYPE_POINT,
+ .token_size = sizeof(struct iw_thrspy),
+ .min_tokens = 1,
+ .max_tokens = 1,
+ },
+ [SIOCGIWTHRSPY - SIOCIWFIRST] = {
+ .header_type = IW_HEADER_TYPE_POINT,
+ .token_size = sizeof(struct iw_thrspy),
+ .min_tokens = 1,
+ .max_tokens = 1,
+ },
+ [SIOCSIWAP - SIOCIWFIRST] = {
+ .header_type = IW_HEADER_TYPE_ADDR,
+ },
+ [SIOCGIWAP - SIOCIWFIRST] = {
+ .header_type = IW_HEADER_TYPE_ADDR,
+ .flags = IW_DESCR_FLAG_DUMP,
+ },
+ [SIOCSIWMLME - SIOCIWFIRST] = {
+ .header_type = IW_HEADER_TYPE_POINT,
+ .token_size = 1,
+ .min_tokens = sizeof(struct iw_mlme),
+ .max_tokens = sizeof(struct iw_mlme),
+ },
+ [SIOCGIWAPLIST - SIOCIWFIRST] = {
+ .header_type = IW_HEADER_TYPE_POINT,
+ .token_size = sizeof(struct sockaddr) +
+ sizeof(struct iw_quality),
+ .max_tokens = IW_MAX_AP,
+ .flags = IW_DESCR_FLAG_NOMAX,
+ },
+ [SIOCSIWSCAN - SIOCIWFIRST] = {
+ .header_type = IW_HEADER_TYPE_POINT,
+ .token_size = 1,
+ .min_tokens = 0,
+ .max_tokens = sizeof(struct iw_scan_req),
+ },
+ [SIOCGIWSCAN - SIOCIWFIRST] = {
+ .header_type = IW_HEADER_TYPE_POINT,
+ .token_size = 1,
+ .max_tokens = IW_SCAN_MAX_DATA,
+ .flags = IW_DESCR_FLAG_NOMAX,
+ },
+ [SIOCSIWESSID - SIOCIWFIRST] = {
+ .header_type = IW_HEADER_TYPE_POINT,
+ .token_size = 1,
+ .max_tokens = IW_ESSID_MAX_SIZE + 1,
+ .flags = IW_DESCR_FLAG_EVENT,
+ },
+ [SIOCGIWESSID - SIOCIWFIRST] = {
+ .header_type = IW_HEADER_TYPE_POINT,
+ .token_size = 1,
+ .max_tokens = IW_ESSID_MAX_SIZE + 1,
+ .flags = IW_DESCR_FLAG_DUMP,
+ },
+ [SIOCSIWNICKN - SIOCIWFIRST] = {
+ .header_type = IW_HEADER_TYPE_POINT,
+ .token_size = 1,
+ .max_tokens = IW_ESSID_MAX_SIZE + 1,
+ },
+ [SIOCGIWNICKN - SIOCIWFIRST] = {
+ .header_type = IW_HEADER_TYPE_POINT,
+ .token_size = 1,
+ .max_tokens = IW_ESSID_MAX_SIZE + 1,
+ },
+ [SIOCSIWRATE - SIOCIWFIRST] = {
+ .header_type = IW_HEADER_TYPE_PARAM,
+ },
+ [SIOCGIWRATE - SIOCIWFIRST] = {
+ .header_type = IW_HEADER_TYPE_PARAM,
+ },
+ [SIOCSIWRTS - SIOCIWFIRST] = {
+ .header_type = IW_HEADER_TYPE_PARAM,
+ },
+ [SIOCGIWRTS - SIOCIWFIRST] = {
+ .header_type = IW_HEADER_TYPE_PARAM,
+ },
+ [SIOCSIWFRAG - SIOCIWFIRST] = {
+ .header_type = IW_HEADER_TYPE_PARAM,
+ },
+ [SIOCGIWFRAG - SIOCIWFIRST] = {
+ .header_type = IW_HEADER_TYPE_PARAM,
+ },
+ [SIOCSIWTXPOW - SIOCIWFIRST] = {
+ .header_type = IW_HEADER_TYPE_PARAM,
+ },
+ [SIOCGIWTXPOW - SIOCIWFIRST] = {
+ .header_type = IW_HEADER_TYPE_PARAM,
+ },
+ [SIOCSIWRETRY - SIOCIWFIRST] = {
+ .header_type = IW_HEADER_TYPE_PARAM,
+ },
+ [SIOCGIWRETRY - SIOCIWFIRST] = {
+ .header_type = IW_HEADER_TYPE_PARAM,
+ },
+ [SIOCSIWENCODE - SIOCIWFIRST] = {
+ .header_type = IW_HEADER_TYPE_POINT,
+ .token_size = 1,
+ .max_tokens = IW_ENCODING_TOKEN_MAX,
+ .flags = IW_DESCR_FLAG_EVENT | IW_DESCR_FLAG_RESTRICT,
+ },
+ [SIOCGIWENCODE - SIOCIWFIRST] = {
+ .header_type = IW_HEADER_TYPE_POINT,
+ .token_size = 1,
+ .max_tokens = IW_ENCODING_TOKEN_MAX,
+ .flags = IW_DESCR_FLAG_DUMP | IW_DESCR_FLAG_RESTRICT,
+ },
+ [SIOCSIWPOWER - SIOCIWFIRST] = {
+ .header_type = IW_HEADER_TYPE_PARAM,
+ },
+ [SIOCGIWPOWER - SIOCIWFIRST] = {
+ .header_type = IW_HEADER_TYPE_PARAM,
+ },
+#ifdef SIOCSIWMODUL
+ [SIOCSIWMODUL - SIOCIWFIRST] = {
+ .header_type = IW_HEADER_TYPE_PARAM,
+ },
+#endif
+#ifdef SIOCGIWMODUL
+ [SIOCGIWMODUL - SIOCIWFIRST] = {
+ .header_type = IW_HEADER_TYPE_PARAM,
+ },
+#endif
+ [SIOCSIWGENIE - SIOCIWFIRST] = {
+ .header_type = IW_HEADER_TYPE_POINT,
+ .token_size = 1,
+ .max_tokens = IW_GENERIC_IE_MAX,
+ },
+ [SIOCGIWGENIE - SIOCIWFIRST] = {
+ .header_type = IW_HEADER_TYPE_POINT,
+ .token_size = 1,
+ .max_tokens = IW_GENERIC_IE_MAX,
+ },
+ [SIOCSIWAUTH - SIOCIWFIRST] = {
+ .header_type = IW_HEADER_TYPE_PARAM,
+ },
+ [SIOCGIWAUTH - SIOCIWFIRST] = {
+ .header_type = IW_HEADER_TYPE_PARAM,
+ },
+ [SIOCSIWENCODEEXT - SIOCIWFIRST] = {
+ .header_type = IW_HEADER_TYPE_POINT,
+ .token_size = 1,
+ .min_tokens = sizeof(struct iw_encode_ext),
+ .max_tokens = sizeof(struct iw_encode_ext) +
+ IW_ENCODING_TOKEN_MAX,
+ },
+ [SIOCGIWENCODEEXT - SIOCIWFIRST] = {
+ .header_type = IW_HEADER_TYPE_POINT,
+ .token_size = 1,
+ .min_tokens = sizeof(struct iw_encode_ext),
+ .max_tokens = sizeof(struct iw_encode_ext) +
+ IW_ENCODING_TOKEN_MAX,
+ },
+ [SIOCSIWPMKSA - SIOCIWFIRST] = {
+ .header_type = IW_HEADER_TYPE_POINT,
+ .token_size = 1,
+ .min_tokens = sizeof(struct iw_pmksa),
+ .max_tokens = sizeof(struct iw_pmksa),
+ },
+};
+
+static const struct iw_ioctl_description standard_event_descr[] = {
+ [IWEVTXDROP - IWEVFIRST] = {
+ .header_type = IW_HEADER_TYPE_ADDR,
+ },
+ [IWEVQUAL - IWEVFIRST] = {
+ .header_type = IW_HEADER_TYPE_QUAL,
+ },
+ [IWEVCUSTOM - IWEVFIRST] = {
+ .header_type = IW_HEADER_TYPE_POINT,
+ .token_size = 1,
+ .max_tokens = IW_CUSTOM_MAX,
+ },
+ [IWEVREGISTERED - IWEVFIRST] = {
+ .header_type = IW_HEADER_TYPE_ADDR,
+ },
+ [IWEVEXPIRED - IWEVFIRST] = {
+ .header_type = IW_HEADER_TYPE_ADDR,
+ },
+ [IWEVGENIE - IWEVFIRST] = {
+ .header_type = IW_HEADER_TYPE_POINT,
+ .token_size = 1,
+ .max_tokens = IW_GENERIC_IE_MAX,
+ },
+ [IWEVMICHAELMICFAILURE - IWEVFIRST] = {
+ .header_type = IW_HEADER_TYPE_POINT,
+ .token_size = 1,
+ .max_tokens = sizeof(struct iw_michaelmicfailure),
+ },
+ [IWEVASSOCREQIE - IWEVFIRST] = {
+ .header_type = IW_HEADER_TYPE_POINT,
+ .token_size = 1,
+ .max_tokens = IW_GENERIC_IE_MAX,
+ },
+ [IWEVASSOCRESPIE - IWEVFIRST] = {
+ .header_type = IW_HEADER_TYPE_POINT,
+ .token_size = 1,
+ .max_tokens = IW_GENERIC_IE_MAX,
+ },
+ [IWEVPMKIDCAND - IWEVFIRST] = {
+ .header_type = IW_HEADER_TYPE_POINT,
+ .token_size = 1,
+ .max_tokens = sizeof(struct iw_pmkid_cand),
+ },
+};
+
+struct stream_descr {
+ char *current; /* Current event in stream of events */
+ char *value; /* Current value in event */
+ char *end; /* End of the stream */
+};
+
+/*
+ * Extract the next event from the event stream.
+ */
+static int iw_extract_event_stream(struct stream_descr *stream,
+ struct iw_event *iwe, int we_version)
+{
+ const struct iw_ioctl_description *descr = NULL;
+ int event_type;
+ unsigned int event_len = 1; /* Invalid */
+ unsigned cmd_index; /* *MUST* be unsigned */
+ char *pointer;
+
+ if (stream->current + IW_EV_LCP_PK_LEN > stream->end)
+ return 0;
+
+ /* Extract the event header to get the event id.
+ * Note : the event may be unaligned, therefore copy... */
+ memcpy((char *)iwe, stream->current, IW_EV_LCP_PK_LEN);
+
+ if (iwe->len <= IW_EV_LCP_PK_LEN)
+ return -1;
+
+ /* Get the type and length of that event */
+ if (iwe->cmd <= SIOCIWLAST) {
+ cmd_index = iwe->cmd - SIOCIWFIRST;
+ if (cmd_index < ARRAY_SIZE(standard_ioctl_descr))
+ descr = standard_ioctl_descr + cmd_index;
+ } else {
+ cmd_index = iwe->cmd - IWEVFIRST;
+ if (cmd_index < ARRAY_SIZE(standard_event_descr))
+ descr = standard_event_descr + cmd_index;
+ }
+
+ /* Unknown events -> event_type = 0 => IW_EV_LCP_PK_LEN */
+ event_type = descr ? descr->header_type : 0;
+ event_len = event_type_size[event_type];
+
+ /* Check if we know about this event */
+ if (event_len <= IW_EV_LCP_PK_LEN) {
+ stream->current += iwe->len; /* Skip to next event */
+ return 2;
+ }
+ event_len -= IW_EV_LCP_PK_LEN;
+
+ /* Fixup for earlier version of WE */
+ if (we_version <= 18 && event_type == IW_HEADER_TYPE_POINT)
+ event_len += IW_EV_POINT_OFF;
+
+ if (stream->value != NULL)
+ pointer = stream->value; /* Next value in event */
+ else
+ pointer = stream->current + IW_EV_LCP_PK_LEN; /* First value in event */
+
+ /* Copy the rest of the event (at least, fixed part) */
+ if (pointer + event_len > stream->end) {
+ stream->current += iwe->len; /* Skip to next event */
+ return -2;
+ }
+
+ /* Fixup for WE-19 and later: pointer no longer in the stream */
+ /* Beware of alignment. Dest has local alignment, not packed */
+ if (we_version > 18 && event_type == IW_HEADER_TYPE_POINT)
+ memcpy((char *)iwe + IW_EV_LCP_LEN + IW_EV_POINT_OFF, pointer, event_len);
+ else
+ memcpy((char *)iwe + IW_EV_LCP_LEN, pointer, event_len);
+
+ /* Skip event in the stream */
+ pointer += event_len;
+
+ /* Special processing for iw_point events */
+ if (event_type == IW_HEADER_TYPE_POINT) {
+ unsigned int extra_len = iwe->len - (event_len + IW_EV_LCP_PK_LEN);
+
+ if (extra_len > 0) {
+ /* Set pointer on variable part (warning : non aligned) */
+ iwe->u.data.pointer = pointer;
+
+ /* Check that we have a descriptor for the command */
+ if (descr == NULL) {
+ /* Can't check payload -> unsafe... */
+ iwe->u.data.pointer = NULL; /* Discard paylod */
+ } else {
+ unsigned int token_len = iwe->u.data.length * descr->token_size;
+ /*
+ * Ugly fixup for alignment issues.
+ * If the kernel is 64 bits and userspace 32 bits, we have an extra 4 + 4
+ * bytes. Fixing that in the kernel would break 64 bits userspace.
+ */
+ if (token_len != extra_len && extra_len >= 4) {
+ union iw_align_u16 {
+ __u16 value;
+ unsigned char byte[2];
+ } alt_dlen;
+ unsigned int alt_token_len;
+
+ /* Userspace seems to not always like unaligned access,
+ * so be careful and make sure to align value.
+ * I hope gcc won't play any of its aliasing tricks... */
+ alt_dlen.byte[0] = *(pointer);
+ alt_dlen.byte[1] = *(pointer + 1);
+ alt_token_len = alt_dlen.value * descr->token_size;
+
+ /* Verify that data is consistent if assuming 64 bit alignment... */
+ if (alt_token_len + 8 == extra_len) {
+
+ /* Ok, let's redo everything */
+ pointer -= event_len;
+ pointer += 4;
+
+ /* Dest has local alignment, not packed */
+ memcpy((char *)iwe + IW_EV_LCP_LEN + IW_EV_POINT_OFF, pointer, event_len);
+ pointer += event_len + 4;
+ token_len = alt_token_len;
+
+ /* We may have no payload */
+ if (alt_token_len)
+ iwe->u.data.pointer = pointer;
+ else
+ iwe->u.data.pointer = NULL;
+ }
+ }
+
+ /* Discard bogus events which advertise more tokens than they carry ... */
+ if (token_len > extra_len)
+ iwe->u.data.pointer = NULL; /* Discard paylod */
+
+ /* Check that the advertised token size is not going to
+ * produce buffer overflow to our caller... */
+ if (iwe->u.data.length > descr->max_tokens
+ && !(descr->flags & IW_DESCR_FLAG_NOMAX))
+ iwe->u.data.pointer = NULL; /* Discard payload */
+
+ /* Same for underflows... */
+ if (iwe->u.data.length < descr->min_tokens)
+ iwe->u.data.pointer = NULL; /* Discard paylod */
+ }
+ } else {
+ /* No data */
+ iwe->u.data.pointer = NULL;
+ }
+
+ stream->current += iwe->len; /* Go to next event */
+ } else {
+ /*
+ * Ugly fixup for alignment issues.
+ * If the kernel is 64 bits and userspace 32 bits, we have an extra 4 bytes.
+ * Fixing that in the kernel would break 64 bits userspace.
+ */
+ if (stream->value == NULL &&
+ ((iwe->len - IW_EV_LCP_PK_LEN) % event_len == 4 ||
+ (iwe->len == 12 && (event_type == IW_HEADER_TYPE_UINT ||
+ event_type == IW_HEADER_TYPE_QUAL)))) {
+
+ pointer -= event_len;
+ pointer += 4;
+
+ /* Beware of alignment. Dest has local alignment, not packed */
+ memcpy((char *)iwe + IW_EV_LCP_LEN, pointer, event_len);
+ pointer += event_len;
+ }
+
+ if (pointer + event_len <= stream->current + iwe->len) {
+ stream->value = pointer; /* Go to next value */
+ } else {
+ stream->value = NULL;
+ stream->current += iwe->len; /* Go to next event */
+ }
+ }
+ return 1;
+}
+
+static void iw_extract_ie(struct iw_event *iwe, struct scan_result *sr)
+{
+ const uint8_t wpa1_oui[3] = { 0x00, 0x50, 0xf2 };
+ uint8_t *buffer = iwe->u.data.pointer;
+ int ielen = 0, ietype, i;
+
+ /* Loop on each IE, each is min. 2 bytes TLV: IE-ID - Length - Value */
+ for (i = 0; i <= iwe->u.data.length - 2; i += ielen + 2) {
+ ietype = buffer[i];
+ ielen = buffer[i + 1];
+
+ switch (ietype) {
+ case 0x30:
+ if (ielen < 4) /* make sure we have enough data */
+ continue;
+ sr->flags |= IW_ENC_CAPA_WPA2;
+ break;
+ case 0xdd:
+ /* Not all IEs that start with 0xdd are WPA1 */
+ if (ielen < 8 || memcmp(buffer + i + 2, wpa1_oui, 3) ||
+ buffer[i + 5] != 1)
+ continue;
+ sr->flags |= IW_ENC_CAPA_WPA;
+ break;
+ }
+ }
+}
+/*----------------- End of code copied from iwlib -----------------------*/
+
+/* Order by descending signal strength. */
+extern int cmp_sig(const struct scan_result *a, const struct scan_result *b)
+{
+ return a->qual.level - b->qual.level;
+}
+
+/* Order by ascending frequency first, then by descending signal strength. */
+extern int cmp_freq_sig(const struct scan_result *a, const struct scan_result *b)
+{
+ return a->freq == b->freq ? cmp_sig(a, b) : a->freq < b->freq;
+}
+
+struct scan_result *get_scan_list(int skfd, const char *ifname, int we_version,
+ scan_cmp_func cmp_scan_result)
+{
+ struct scan_result *head = NULL;
+ struct iwreq wrq;
+ int wait, waited = 0;
+
+ /*
+ * Some drivers may return very large scan results, either because there
+ * are many cells, or there are many large elements. Do not bother to
+ * guess buffer size, use maximum u16 wrq.u.data.length size.
+ */
+ char scan_buf[0xffff];
+
+ /* We are checking errno when returning NULL, so reset it here */
+ errno = 0;
+
+ memset(&wrq, 0, sizeof(wrq));
+ strncpy(wrq.ifr_ifrn.ifrn_name, ifname, IFNAMSIZ);
+ if (ioctl(skfd, SIOCSIWSCAN, &wrq) < 0)
+ return NULL;
+
+ /* Larger initial timeout of 250ms between set and first get */
+ for (wait = 250; (waited += wait) < MAX_SCAN_WAIT; wait = 100) {
+ struct timeval tv = { 0, wait * 1000 };
+
+ while (select(0, NULL, NULL, NULL, &tv) < 0)
+ if (errno != EINTR && errno != EAGAIN)
+ return NULL;
+
+ wrq.u.data.pointer = scan_buf;
+ wrq.u.data.length = sizeof(scan_buf);
+ wrq.u.data.flags = 0;
+
+ if (ioctl(skfd, SIOCGIWSCAN, &wrq) == 0)
+ break;
+ }
+
+ if (wrq.u.data.length) {
+ struct iw_event iwe;
+ struct stream_descr stream;
+ struct scan_result *new = NULL;
+ int f = 0; /* Idea taken from waproamd */
+
+ memset(&stream, 0, sizeof(stream));
+ stream.current = scan_buf;
+ stream.end = scan_buf + wrq.u.data.length;
+
+ while (iw_extract_event_stream(&stream, &iwe, we_version) > 0) {
+ if (!new)
+ new = calloc(1, sizeof(*new));
+
+ switch (iwe.cmd) {
+ case SIOCGIWAP:
+ f = 1;
+ memcpy(&new->ap_addr, &iwe.u.ap_addr.sa_data, sizeof(new->ap_addr));
+ break;
+ case SIOCGIWESSID:
+ f |= 2;
+ memset(new->essid, 0, sizeof(new->essid));
+
+ if (iwe.u.essid.flags && iwe.u.essid.pointer && iwe.u.essid.length)
+ memcpy(new->essid, iwe.u.essid.pointer, iwe.u.essid.length);
+ break;
+ case SIOCGIWMODE:
+ new->mode = iwe.u.mode;
+ f |= 4;
+ break;
+ case SIOCGIWFREQ:
+ f |= 8;
+ new->freq = freq_to_hz(&iwe.u.freq);
+ break;
+ case SIOCGIWENCODE:
+ f |= 16;
+ new->has_key = !(iwe.u.data.flags & IW_ENCODE_DISABLED);
+ break;
+ case IWEVQUAL:
+ f |= 32;
+ memcpy(&new->qual, &iwe.u.qual, sizeof(struct iw_quality));
+ break;
+ case IWEVGENIE:
+ f |= 64;
+ iw_extract_ie(&iwe, new);
+ break;
+ }
+ if (f == 127) {
+ struct scan_result *cur = head, **prev = &head;
+
+ f = 0;
+
+ while (cur && cmp_scan_result(cur, new) > 0)
+ prev = &cur->next, cur = cur->next;
+
+ *prev = new;
+ new->next = cur;
+ new = NULL;
+ }
+ }
+ free(new); /* may have been allocated but not filled in */
+ }
+ return head;
+}
+
+void free_scan_result(struct scan_result *head)
+{
+ if (head) {
+ free_scan_result(head->next);
+ free(head);
+ }
+}