iw: scan: replace passed ie buffer with ie context

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>
Link: https://patch.msgid.link/20241122161851.647214-1-dylan.eskew@candelatech.com
[cleanups]
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

diff --git a/scan.c b/scan.c
index 3bc6fb48aab89f5fbcc248ce9e2c37ae5da0bd8a..6cf44d2501625f8256573c80db95fd17022fe605 100644 (file)
--- 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 +1321,10 @@ 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;
-
-       while (ielen >= 2 && ielen >= ie[1]) {
-               if (ie[0] == 191) {
-                       is_vht_cap = true;
-                       break;
-               }
-               ielen -= ie[1] + 2;
-               ie += ie[1] + 2;
-       }
+       bool s_psmp_support = false;
 
        for (i = 0; i < len; i++) {
                base = i * 8;
@@ -1432,8 +1420,8 @@ 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 +1450,7 @@ 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 +1474,7 @@ 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 +1485,13 @@ 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 +1500,7 @@ 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 +1519,7 @@ 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 +1553,7 @@ 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 +1602,7 @@ 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 +1617,7 @@ 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 +1626,7 @@ 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 +1636,7 @@ 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 +1669,7 @@ 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 +1677,14 @@ 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 +1765,14 @@ 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 +1793,7 @@ 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 +1855,14 @@ 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 +1910,7 @@ 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 +1953,7 @@ 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 +2193,7 @@ 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 +2275,7 @@ 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 +2287,7 @@ 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 +2380,14 @@ 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 +2425,46 @@ static void print_extension(unsigned char len, unsigned char *ie,
        }
 }
 
+static void init_context(struct ie_context *ctx,
+                        unsigned char *ie, int ielen)
+{
+       unsigned char *pos = ie;
+       int remaining = ielen;
+
+       memset(ctx, 0, sizeof(*ctx));
+
+       if (!ie || !ielen)
+               return;
+
+       while (remaining >= 2 && remaining - 2 >= pos[1]) {
+               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;
 
-       if (ie == NULL || ielen < 0)
+       if (!ie)
                return;
 
+       init_context(&ctx, ie, ielen);
+
        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 */) {