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00016 #include "includes.h"
00017 #include "common.h"
00018 #include "wps/wps.h"
00019 #include "wps/wps_i.h"
00020
00021 #define FLAG_MESSAGE_BEGIN (1 << 7)
00022 #define FLAG_MESSAGE_END (1 << 6)
00023 #define FLAG_CHUNK (1 << 5)
00024 #define FLAG_SHORT_RECORD (1 << 4)
00025 #define FLAG_ID_LENGTH_PRESENT (1 << 3)
00026 #define FLAG_TNF_RFC2046 (0x02)
00027
00028 struct ndef_record {
00029 u8 *type;
00030 u8 *id;
00031 u8 *payload;
00032 u8 type_length;
00033 u8 id_length;
00034 u32 payload_length;
00035 u32 total_length;
00036 };
00037
00038 static char wifi_handover_type[] = "application/vnd.wfa.wsc";
00039
00040 static int ndef_parse_record(u8 *data, u32 size, struct ndef_record *record)
00041 {
00042 u8 *pos = data + 1;
00043
00044 if (size < 2)
00045 return -1;
00046 record->type_length = *pos++;
00047 if (data[0] & FLAG_SHORT_RECORD) {
00048 if (size < 3)
00049 return -1;
00050 record->payload_length = *pos++;
00051 } else {
00052 if (size < 6)
00053 return -1;
00054 record->payload_length = ntohl(*(u32 *)pos);
00055 pos += sizeof(u32);
00056 }
00057
00058 if (data[0] & FLAG_ID_LENGTH_PRESENT) {
00059 if ((int) size < pos - data + 1)
00060 return -1;
00061 record->id_length = *pos++;
00062 } else
00063 record->id_length = 0;
00064
00065 record->type = record->type_length == 0 ? NULL : pos;
00066 pos += record->type_length;
00067
00068 record->id = record->id_length == 0 ? NULL : pos;
00069 pos += record->id_length;
00070
00071 record->payload = record->payload_length == 0 ? NULL : pos;
00072 pos += record->payload_length;
00073
00074 record->total_length = pos - data;
00075 if (record->total_length > size)
00076 return -1;
00077 return 0;
00078 }
00079
00080
00081 static struct wpabuf * ndef_parse_records(struct wpabuf *buf,
00082 int (*filter)(struct ndef_record *))
00083 {
00084 struct ndef_record record;
00085 int len = wpabuf_len(buf);
00086 u8 *data = wpabuf_mhead(buf);
00087
00088 while (len > 0) {
00089 if (ndef_parse_record(data, len, &record) < 0) {
00090 wpa_printf(MSG_ERROR, "NDEF : Failed to parse");
00091 return NULL;
00092 }
00093 if (filter == NULL || filter(&record))
00094 return wpabuf_alloc_copy(record.payload,
00095 record.payload_length);
00096 data += record.total_length;
00097 len -= record.total_length;
00098 }
00099 wpa_printf(MSG_ERROR, "NDEF : Record not found");
00100 return NULL;
00101 }
00102
00103
00104 static struct wpabuf * ndef_build_record(u8 flags, void *type,
00105 u8 type_length, void *id,
00106 u8 id_length, void *payload,
00107 u32 payload_length)
00108 {
00109 struct wpabuf *record;
00110 size_t total_len;
00111 int short_record;
00112 u8 local_flag;
00113
00114 short_record = payload_length < 256 ? 1 : 0;
00115
00116 total_len = 2;
00117
00118 total_len += short_record ? sizeof(u8) : sizeof(u32);
00119 if (id_length > 0)
00120 total_len += 1;
00121 total_len += type_length + id_length + payload_length;
00122 record = wpabuf_alloc(total_len);
00123 if (record == NULL) {
00124 wpa_printf(MSG_ERROR, "NDEF : Failed to allocate "
00125 "record for build");
00126 return NULL;
00127 }
00128
00129 local_flag = flags;
00130 if (id_length > 0)
00131 local_flag |= FLAG_ID_LENGTH_PRESENT;
00132 if (short_record)
00133 local_flag |= FLAG_SHORT_RECORD;
00134 wpabuf_put_u8(record, local_flag);
00135
00136 wpabuf_put_u8(record, type_length);
00137
00138 if (short_record)
00139 wpabuf_put_u8(record, payload_length);
00140 else
00141 wpabuf_put_be32(record, payload_length);
00142
00143 if (id_length > 0)
00144 wpabuf_put_u8(record, id_length);
00145 wpabuf_put_data(record, type, type_length);
00146 wpabuf_put_data(record, id, id_length);
00147 wpabuf_put_data(record, payload, payload_length);
00148 return record;
00149 }
00150
00151
00152 static int wifi_filter(struct ndef_record *record)
00153 {
00154 if (record->type_length != os_strlen(wifi_handover_type))
00155 return 0;
00156 if (os_memcmp(record->type, wifi_handover_type,
00157 os_strlen(wifi_handover_type)) != 0)
00158 return 0;
00159 return 1;
00160 }
00161
00162
00163 struct wpabuf * ndef_parse_wifi(struct wpabuf *buf)
00164 {
00165 return ndef_parse_records(buf, wifi_filter);
00166 }
00167
00168
00169 struct wpabuf * ndef_build_wifi(struct wpabuf *buf)
00170 {
00171 return ndef_build_record(FLAG_MESSAGE_BEGIN | FLAG_MESSAGE_END |
00172 FLAG_TNF_RFC2046, wifi_handover_type,
00173 os_strlen(wifi_handover_type), NULL, 0,
00174 wpabuf_mhead(buf), wpabuf_len(buf));
00175 }