diff mbox series

[v2,2/3] iw: scan: replace passed ie buffer with ie context

Message ID 20241122161851.647214-1-dylan.eskew@candelatech.com
State New
Headers show
Series None | expand

Commit Message

Dylan Eskew Nov. 22, 2024, 4:18 p.m. UTC 
Since some ies require references to other ies, parse
the ie list once before to create a context and prevent
parsing more than the two times required.

Signed-off-by: Dylan Eskew <dylan.eskew@candelatech.com>
---
v2:
  - Replace in-place parsing with building a context in a first pass
---
 scan.c | 141 +++++++++++++++++++++++++++++++--------------------------
 1 file changed, 78 insertions(+), 63 deletions(-)
diff mbox series

Patch

diff --git a/scan.c b/scan.c
index 3bc6fb4..de0dd38 100644
--- a/scan.c
+++ b/scan.c
@@ -554,13 +554,12 @@  static void tab_on_first(bool *first)
 		*first = false;
 }
 
-struct print_ies_data {
-	unsigned char *ie;
-	int ielen;
+struct ie_context {
+	bool is_vht_cap;
 };
 
 static void print_ssid(const uint8_t type, uint8_t len, const uint8_t *data,
-		       const struct print_ies_data *ie_buffer)
+		       const struct ie_context *ctx)
 {
 	printf(" ");
 	print_ssid_escaped(len, data);
@@ -572,7 +571,7 @@  static void print_ssid(const uint8_t type, uint8_t len, const uint8_t *data,
 
 static void print_supprates(const uint8_t type, uint8_t len,
 			    const uint8_t *data,
-			    const struct print_ies_data *ie_buffer)
+			    const struct ie_context *ctx)
 {
 	int i;
 
@@ -595,7 +594,7 @@  static void print_supprates(const uint8_t type, uint8_t len,
 
 static void print_rm_enabled_capabilities(const uint8_t type, uint8_t len,
 			    const uint8_t *data,
-			    const struct print_ies_data *ie_buffer)
+			    const struct ie_context *ctx)
 {
 	__u64 capa = ((__u64) data[0]) |
 		     ((__u64) data[1]) << 8 |
@@ -649,7 +648,7 @@  static void print_rm_enabled_capabilities(const uint8_t type, uint8_t len,
 }
 
 static void print_ds(const uint8_t type, uint8_t len, const uint8_t *data,
-		     const struct print_ies_data *ie_buffer)
+		     const struct ie_context *ctx)
 {
 	printf(" channel %d\n", data[0]);
 }
@@ -669,7 +668,7 @@  static const char *country_env_str(char environment)
 }
 
 static void print_country(const uint8_t type, uint8_t len, const uint8_t *data,
-			  const struct print_ies_data *ie_buffer)
+			  const struct ie_context *ctx)
 {
 	printf(" %.*s", 2, data);
 
@@ -716,21 +715,21 @@  static void print_country(const uint8_t type, uint8_t len, const uint8_t *data,
 
 static void print_powerconstraint(const uint8_t type, uint8_t len,
 				  const uint8_t *data,
-				  const struct print_ies_data *ie_buffer)
+				  const struct ie_context *ctx)
 {
 	printf(" %d dB\n", data[0]);
 }
 
 static void print_tpcreport(const uint8_t type, uint8_t len,
 			    const uint8_t *data,
-			    const struct print_ies_data *ie_buffer)
+			    const struct ie_context *ctx)
 {
 	printf(" TX power: %d dBm\n", data[0]);
 	/* printf(" Link Margin (%d dB) is reserved in Beacons\n", data[1]); */
 }
 
 static void print_erp(const uint8_t type, uint8_t len, const uint8_t *data,
-		      const struct print_ies_data *ie_buffer)
+		      const struct ie_context *ctx)
 {
 	if (data[0] == 0x00)
 		printf(" <no flags>");
@@ -744,7 +743,7 @@  static void print_erp(const uint8_t type, uint8_t len, const uint8_t *data,
 }
 
 static void print_ap_channel_report(const uint8_t type, uint8_t len, const uint8_t *data,
-				    const struct print_ies_data *ie_buffer)
+				    const struct ie_context *ctx)
 {
 	uint8_t oper_class = data[0];
 	int i;
@@ -1084,13 +1083,13 @@  static void print_osen_ie(const char *defcipher, const char *defauth,
 }
 
 static void print_rsn(const uint8_t type, uint8_t len, const uint8_t *data,
-		      const struct print_ies_data *ie_buffer)
+		      const struct ie_context *ctx)
 {
 	print_rsn_ie("CCMP", "IEEE 802.1X", len, data);
 }
 
 static void print_ht_capa(const uint8_t type, uint8_t len, const uint8_t *data,
-			  const struct print_ies_data *ie_buffer)
+			  const struct ie_context *ctx)
 {
 	printf("\n");
 	print_ht_capability(data[0] | (data[1] << 8));
@@ -1135,7 +1134,7 @@  static const char* vgroup_11u(uint8_t t)
 
 static void print_interworking(const uint8_t type, uint8_t len,
 			       const uint8_t *data,
-			       const struct print_ies_data *ie_buffer)
+			       const struct ie_context *ctx)
 {
 	/* See Section 7.3.2.92 in the 802.11u spec. */
 	printf("\n");
@@ -1168,7 +1167,7 @@  static void print_interworking(const uint8_t type, uint8_t len,
 
 static void print_11u_advert(const uint8_t type, uint8_t len,
 			     const uint8_t *data,
-			     const struct print_ies_data *ie_buffer)
+			     const struct ie_context *ctx)
 {
 	/* See Section 7.3.2.93 in the 802.11u spec. */
 	/* TODO: This code below does not decode private protocol IDs */
@@ -1201,7 +1200,7 @@  static void print_11u_advert(const uint8_t type, uint8_t len,
 }
 
 static void print_11u_rcon(const uint8_t type, uint8_t len, const uint8_t *data,
-			   const struct print_ies_data *ie_buffer)
+			   const struct ie_context *ctx)
 {
 	/* See Section 7.3.2.96 in the 802.11u spec. */
 	int idx = 0;
@@ -1254,7 +1253,7 @@  static void print_11u_rcon(const uint8_t type, uint8_t len, const uint8_t *data,
 
 static void print_tx_power_envelope(const uint8_t type, uint8_t len,
 				    const uint8_t *data,
-				    const struct print_ies_data *ie_buffer)
+				    const struct ie_context *ctx)
 {
 	const uint8_t local_max_tx_power_count = data[0] & 7;
 	const uint8_t local_max_tx_power_unit_interp = (data[0] >> 3) & 7;
@@ -1290,7 +1289,7 @@  static const char *ht_secondary_offset[4] = {
 };
 
 static void print_ht_op(const uint8_t type, uint8_t len, const uint8_t *data,
-			const struct print_ies_data *ie_buffer)
+			const struct ie_context *ctx)
 {
 	static const char *protection[4] = {
 		"no",
@@ -1322,21 +1321,11 @@  static void print_ht_op(const uint8_t type, uint8_t len, const uint8_t *data,
 
 static void print_capabilities(const uint8_t type, uint8_t len,
 			       const uint8_t *data,
-			       const struct print_ies_data *ie_buffer)
+			       const struct ie_context *ctx)
 {
 	int i, base, bit, si_duration = 0, max_amsdu = 0;
-	bool s_psmp_support = false, is_vht_cap = false;
-	unsigned char *ie = ie_buffer->ie;
-	int ielen = ie_buffer->ielen;
+	bool s_psmp_support = false;
 
-	while (ielen >= 2 && ielen >= ie[1]) {
-		if (ie[0] == 191) {
-			is_vht_cap = true;
-			break;
-		}
-		ielen -= ie[1] + 2;
-		ie += ie[1] + 2;
-	}
 
 	for (i = 0; i < len; i++) {
 		base = i * 8;
@@ -1432,8 +1421,8 @@  static void print_capabilities(const uint8_t type, uint8_t len,
 			CAPA(61, "TDLS Wider Bandwidth");
 			CAPA(62, "Operating Mode Notification");
 
-			ADD_BIT_VAL(63, is_vht_cap, max_amsdu, 1);
-			ADD_BIT_VAL(64, is_vht_cap, max_amsdu, 2);
+			ADD_BIT_VAL(63, ctx->is_vht_cap, max_amsdu, 1);
+			ADD_BIT_VAL(64, ctx->is_vht_cap, max_amsdu, 2);
 
 			CAPA(65, "Channel Schedule Management");
 			CAPA(66, "Geodatabase Inband Enabling Signal");
@@ -1462,7 +1451,7 @@  static void print_capabilities(const uint8_t type, uint8_t len,
 		printf("\n\t\t * Service Interval Granularity is %d ms",
 		       (si_duration + 1) * 5);
 
-	if (is_vht_cap) {
+	if (ctx->is_vht_cap) {
 		printf("\n\t\t * Max Number Of MSDUs In A-MSDU is ");
 		switch (max_amsdu) {
 		case 0:
@@ -1486,7 +1475,7 @@  static void print_capabilities(const uint8_t type, uint8_t len,
 }
 
 static void print_tim(const uint8_t type, uint8_t len, const uint8_t *data,
-		      const struct print_ies_data *ie_buffer)
+		      const struct ie_context *ctx)
 {
 	printf(" DTIM Count %u DTIM Period %u Bitmap Control 0x%x "
 	       "Bitmap[0] 0x%x",
@@ -1497,13 +1486,13 @@  static void print_tim(const uint8_t type, uint8_t len, const uint8_t *data,
 }
 
 static void print_ibssatim(const uint8_t type, uint8_t len, const uint8_t *data,
-			   const struct print_ies_data *ie_buffer)
+			   const struct ie_context *ctx)
 {
 	printf(" %d TUs\n", (data[1] << 8) + data[0]);
 }
 
 static void print_vht_capa(const uint8_t type, uint8_t len, const uint8_t *data,
-			   const struct print_ies_data *ie_buffer)
+			   const struct ie_context *ctx)
 {
 	printf("\n");
 	print_vht_info((__u32) data[0] | ((__u32)data[1] << 8) |
@@ -1512,7 +1501,7 @@  static void print_vht_capa(const uint8_t type, uint8_t len, const uint8_t *data,
 }
 
 static void print_vht_oper(const uint8_t type, uint8_t len, const uint8_t *data,
-			   const struct print_ies_data *ie_buffer)
+			   const struct ie_context *ctx)
 {
 	const char *chandwidths[] = {
 		[0] = "20 or 40 MHz",
@@ -1531,7 +1520,7 @@  static void print_vht_oper(const uint8_t type, uint8_t len, const uint8_t *data,
 
 static void print_supp_op_classes(const uint8_t type, uint8_t len,
 				  const uint8_t *data,
-				  const struct print_ies_data *ie_buffer)
+				  const struct ie_context *ctx)
 {
 	uint8_t *p = (uint8_t*) data;
 	const uint8_t *next_data = p + len;
@@ -1565,7 +1554,7 @@  static void print_supp_op_classes(const uint8_t type, uint8_t len,
 
 static void print_measurement_pilot_tx(const uint8_t type, uint8_t len,
 				       const uint8_t *data,
-				       const struct print_ies_data *ie_buffer)
+				       const struct ie_context *ctx)
 {
 	uint8_t *p, len_remaining;
 
@@ -1614,7 +1603,7 @@  static void print_measurement_pilot_tx(const uint8_t type, uint8_t len,
 
 static void print_obss_scan_params(const uint8_t type, uint8_t len,
 				   const uint8_t *data,
-				   const struct print_ies_data *ie_buffer)
+				   const struct ie_context *ctx)
 {
 	printf("\n");
 	printf("\t\t * passive dwell: %d TUs\n", (data[1] << 8) | data[0]);
@@ -1629,7 +1618,7 @@  static void print_obss_scan_params(const uint8_t type, uint8_t len,
 
 static void print_secchan_offs(const uint8_t type, uint8_t len,
 			       const uint8_t *data,
-			       const struct print_ies_data *ie_buffer)
+			       const struct ie_context *ctx)
 {
 	if (data[0] < ARRAY_SIZE(ht_secondary_offset))
 		printf(" %s (%d)\n", ht_secondary_offset[data[0]], data[0]);
@@ -1638,7 +1627,7 @@  static void print_secchan_offs(const uint8_t type, uint8_t len,
 }
 
 static void print_bss_load(const uint8_t type, uint8_t len, const uint8_t *data,
-			   const struct print_ies_data *ie_buffer)
+			   const struct ie_context *ctx)
 {
 	printf("\n");
 	printf("\t\t * station count: %d\n", (data[1] << 8) | data[0]);
@@ -1648,7 +1637,7 @@  static void print_bss_load(const uint8_t type, uint8_t len, const uint8_t *data,
 
 static void print_mesh_conf(const uint8_t type, uint8_t len,
 			    const uint8_t *data,
-			    const struct print_ies_data *ie_buffer)
+			    const struct ie_context *ctx)
 {
 	printf("\n");
 	printf("\t\t * Active Path Selection Protocol ID: %d\n", data[0]);
@@ -1681,7 +1670,7 @@  static void print_mesh_conf(const uint8_t type, uint8_t len,
 
 static void print_s1g_capa(const uint8_t type, uint8_t len,
 			    const uint8_t *data,
-			    const struct print_ies_data *ie_buffer)
+			    const struct ie_context *ctx)
 {
 	printf("\n");
 	print_s1g_capability(data);
@@ -1689,14 +1678,14 @@  static void print_s1g_capa(const uint8_t type, uint8_t len,
 
 static void print_short_beacon_int(const uint8_t type, uint8_t len,
 			    const uint8_t *data,
-			    const struct print_ies_data *ie_buffer)
+			    const struct ie_context *ctx)
 {
 	printf(" %d\n", (data[1] << 8) | data[0]);
 }
 
 static void print_s1g_oper(const uint8_t type, uint8_t len,
 			    const uint8_t *data,
-			    const struct print_ies_data *ie_buffer)
+			    const struct ie_context *ctx)
 {
 	int oper_ch_width, prim_ch_width;
 	int prim_ch_width_subfield = data[0] & 0x1;
@@ -1777,14 +1766,14 @@  static void print_s1g_oper(const uint8_t type, uint8_t len,
 struct ie_print {
 	const char *name;
 	void (*print)(const uint8_t type, uint8_t len, const uint8_t *data,
-		      const struct print_ies_data *ie_buffer);
+		      const struct ie_context *ctx);
 	uint8_t minlen, maxlen;
 	uint8_t flags;
 };
 
 static void print_ie(const struct ie_print *p, const uint8_t type, uint8_t len,
 		     const uint8_t *data,
-		     const struct print_ies_data *ie_buffer)
+		     const struct ie_context *ctx)
 {
 	int i;
 
@@ -1805,7 +1794,7 @@  static void print_ie(const struct ie_print *p, const uint8_t type, uint8_t len,
 		return;
 	}
 
-	p->print(type, len, data, ie_buffer);
+	p->print(type, len, data, ctx);
 }
 
 #define PRINT_IGN {		\
@@ -1867,14 +1856,14 @@  static const struct ie_print ieprinters[] = {
 };
 
 static void print_wifi_wpa(const uint8_t type, uint8_t len, const uint8_t *data,
-			   const struct print_ies_data *ie_buffer)
+			   const struct ie_context *ctx)
 {
 	print_rsn_ie("TKIP", "IEEE 802.1X", len, data);
 }
 
 static void print_wifi_osen(const uint8_t type, uint8_t len,
 			    const uint8_t *data,
-			    const struct print_ies_data *ie_buffer)
+			    const struct ie_context *ctx)
 {
 	print_osen_ie("OSEN", "OSEN", len, data);
 }
@@ -1922,7 +1911,7 @@  static bool print_wifi_wmm_param(const uint8_t *data, uint8_t len)
 }
 
 static void print_wifi_wmm(const uint8_t type, uint8_t len, const uint8_t *data,
-			   const struct print_ies_data *ie_buffer)
+			   const struct ie_context *ctx)
 {
 	int i;
 
@@ -1965,7 +1954,7 @@  static const char * wifi_wps_dev_passwd_id(uint16_t id)
 }
 
 static void print_wifi_wps(const uint8_t type, uint8_t len, const uint8_t *data,
-			   const struct print_ies_data *ie_buffer)
+			   const struct ie_context *ctx)
 {
 	bool first = true;
 	__u16 subtype, sublen;
@@ -2205,7 +2194,7 @@  static const struct ie_print wifiprinters[] = {
 
 static inline void print_p2p(const uint8_t type, uint8_t len,
 			     const uint8_t *data,
-			     const struct print_ies_data *ie_buffer)
+			     const struct ie_context *ctx)
 {
 	bool first = true;
 	__u8 subtype;
@@ -2287,7 +2276,7 @@  static inline void print_p2p(const uint8_t type, uint8_t len,
 
 static inline void print_hs20_ind(const uint8_t type, uint8_t len,
 				  const uint8_t *data,
-				  const struct print_ies_data *ie_buffer)
+				  const struct ie_context *ctx)
 {
 	/* I can't find the spec for this...just going off what wireshark uses. */
 	printf("\n");
@@ -2299,7 +2288,7 @@  static inline void print_hs20_ind(const uint8_t type, uint8_t len,
 
 static void print_wifi_owe_tarns(const uint8_t type, uint8_t len,
 				 const uint8_t *data,
-				 const struct print_ies_data *ie_buffer)
+				 const struct ie_context *ctx)
 {
 	char mac_addr[20];
 	int ssid_len;
@@ -2392,14 +2381,14 @@  static void print_vendor(unsigned char len, unsigned char *data,
 }
 
 static void print_he_capa(const uint8_t type, uint8_t len, const uint8_t *data,
-			  const struct print_ies_data *ie_buffer)
+			  const struct ie_context *ctx)
 {
 	printf("\n");
 	print_he_capability(data, len);
 }
 
 static void print_he_oper(const uint8_t type, uint8_t len, const uint8_t *data,
-			  const struct print_ies_data *ie_buffer)
+			  const struct ie_context *ctx)
 {
 	printf("\n");
 	print_he_operation(data, len);
@@ -2437,23 +2426,49 @@  static void print_extension(unsigned char len, unsigned char *ie,
 	}
 }
 
+static void set_context(unsigned char *ie, int ielen, struct ie_context *ctx)
+{
+	unsigned char *pos = ie;
+	int remaining = ielen;
+
+	if (ie == NULL || ielen == 0 || ctx == NULL)
+		return;
+
+	while (remaining >= 2 && remaining - 2 >= pos[1]) {
+		if (pos[0] == EID_EXTENSION) {
+			/*switch (pos[2]) {
+			 * for future use
+			}*/
+		} else {
+			switch (pos[0]) {
+			case EID_VHT_CAPABILITY:
+				ctx->is_vht_cap = true;
+				break;
+			}
+		}
+
+		remaining -= pos[1] + 2;
+		pos += pos[1] + 2;
+	}
+}
+
 void print_ies(unsigned char *ie, int ielen, bool unknown,
 	       enum print_ie_type ptype)
 {
-	struct print_ies_data ie_buffer = {
-		.ie = ie,
-		.ielen = ielen };
+	struct ie_context ctx = { 0 };
 
 	if (ie == NULL || ielen < 0)
 		return;
 
+	set_context(ie, ielen, &ctx);
+
 	while (ielen >= 2 && ielen - 2 >= ie[1]) {
 		if (ie[0] < ARRAY_SIZE(ieprinters) &&
 		    ieprinters[ie[0]].name &&
 		    ieprinters[ie[0]].flags & BIT(ptype) &&
 			    ie[1] > 0) {
 			print_ie(&ieprinters[ie[0]],
-				 ie[0], ie[1], ie + 2, &ie_buffer);
+				 ie[0], ie[1], ie + 2, &ctx);
 		} else if (ie[0] == 221 /* vendor */) {
 			print_vendor(ie[1], ie + 2, unknown, ptype);
 		} else if (ie[0] == 255 /* extension */) {