wlantest/rx_ip.c

   1 /*
   2  * Received Data frame processing for IPv4 packets
   3  * Copyright (c) 2010, Jouni Malinen <j@w1.fi>
   4  *
   5  * This software may be distributed under the terms of the BSD license.
   6  * See README for more details.
   7  */
   8
   9 #include "utils/includes.h"
  10 #include <netinet/ip.h>
  11 #include <netinet/ip_icmp.h>
  12
  13 #include "utils/common.h"
  14 #include "wlantest.h"
  15
  16
  17 static void ping_update(struct wlantest *wt, struct wlantest_sta *sta, int req,
  18                         u32 src, u32 dst, u16 id, u16 seq)
  19 {
  20         if (req) {
  21                 sta->icmp_echo_req_src = src;
  22                 sta->icmp_echo_req_dst = dst;
  23                 sta->icmp_echo_req_id = id;
  24                 sta->icmp_echo_req_seq = seq;
  25                 return;
  26         }
  27
  28         if (sta->icmp_echo_req_src == dst &&
  29             sta->icmp_echo_req_dst == src &&
  30             sta->icmp_echo_req_id == id &&
  31             sta->icmp_echo_req_seq == seq) {
  32                 sta->counters[WLANTEST_STA_COUNTER_PING_OK]++;
  33                 if (sta->counters[WLANTEST_STA_COUNTER_ASSOCREQ_TX] == 0 &&
  34                     sta->counters[WLANTEST_STA_COUNTER_REASSOCREQ_TX] == 0)
  35                         sta->counters[
  36                                 WLANTEST_STA_COUNTER_PING_OK_FIRST_ASSOC]++;
  37                 add_note(wt, MSG_DEBUG, "ICMP echo (ping) match for STA "
  38                          MACSTR, MAC2STR(sta->addr));
  39         }
  40 }
  41
  42
  43 static void rx_data_icmp(struct wlantest *wt, const u8 *bssid,
  44                          const u8 *sta_addr, u32 dst, u32 src,
  45                          const u8 *data, size_t len, const u8 *peer_addr)
  46 {
  47         struct in_addr addr;
  48         char buf[20];
  49         const struct icmphdr *hdr;
  50         u16 id, seq;
  51         struct wlantest_bss *bss;
  52         struct wlantest_sta *sta;
  53
  54         hdr = (const struct icmphdr *) data;
  55         if (len < 4)
  56                 return;
  57
  58         /* TODO: check hdr->checksum */
  59
  60         if (hdr->type != ICMP_ECHOREPLY && hdr->type != ICMP_ECHO)
  61                 return;
  62         if (len < 8)
  63                 return;
  64
  65         id = ntohs(hdr->un.echo.id);
  66         seq = ntohs(hdr->un.echo.sequence);
  67
  68         addr.s_addr = dst;
  69         snprintf(buf, sizeof(buf), "%s", inet_ntoa(addr));
  70         addr.s_addr = src;
  71         add_note(wt, MSG_DEBUG, "ICMP echo %s %s -> %s id=%04x seq=%u len=%u%s",
  72                  hdr->type == ICMP_ECHO ? "request" : "response",
  73                  inet_ntoa(addr), buf, id, seq, (unsigned) len - 8,
  74                  peer_addr ? " [DL]" : "");
  75
  76         bss = bss_find(wt, bssid);
  77         if (bss == NULL) {
  78                 add_note(wt, MSG_INFO, "No BSS " MACSTR
  79                          " known for ICMP packet", MAC2STR(bssid));
  80                 return;
  81         }
  82
  83         if (sta_addr == NULL)
  84                 return; /* FromDS broadcast ping */
  85
  86         sta = sta_find(bss, sta_addr);
  87         if (sta == NULL) {
  88                 add_note(wt, MSG_INFO, "No STA " MACSTR
  89                          " known for ICMP packet", MAC2STR(sta_addr));
  90                 return;
  91         }
  92
  93         ping_update(wt, sta, hdr->type == ICMP_ECHO, src, dst, id, seq);
  94         if (peer_addr && (sta = sta_find(bss, peer_addr)))
  95                 ping_update(wt, sta, hdr->type == ICMP_ECHO, src, dst, id, seq);
  96 }
  97
  98
  99 static int hwsim_test_packet(const u8 *data, size_t len)
 100 {
 101         size_t i;
 102
 103         if (len != 1500 - 14)
 104                 return 0;
 105
 106         for (i = 0; i < len; i++) {
 107                 if (data[i] != (i & 0xff))
 108                         return 0;
 109         }
 110
 111         return 1;
 112 }
 113
 114
 115 void rx_data_ip(struct wlantest *wt, const u8 *bssid, const u8 *sta_addr,
 116                 const u8 *dst, const u8 *src, const u8 *data, size_t len,
 117                 const u8 *peer_addr)
 118 {
 119         const struct iphdr *ip;
 120         const u8 *payload;
 121         size_t plen;
 122         u16 frag_off, tot_len;
 123
 124         ip = (const struct iphdr *) data;
 125         if (len < sizeof(*ip))
 126                 return;
 127         if (ip->version != 4) {
 128                 if (hwsim_test_packet(data, len)) {
 129                         add_note(wt, MSG_INFO, "hwsim_test package");
 130                         return;
 131                 }
 132                 add_note(wt, MSG_DEBUG, "Unexpected IP protocol version %u in "
 133                          "IPv4 packet (bssid=" MACSTR " str=" MACSTR
 134                          " dst=" MACSTR ")", ip->version, MAC2STR(bssid),
 135                          MAC2STR(src), MAC2STR(dst));
 136                 return;
 137         }
 138         if (ip->ihl * 4 < sizeof(*ip)) {
 139                 add_note(wt, MSG_DEBUG, "Unexpected IP header length %u in "
 140                          "IPv4 packet (bssid=" MACSTR " str=" MACSTR
 141                          " dst=" MACSTR ")", ip->ihl, MAC2STR(bssid),
 142                          MAC2STR(src), MAC2STR(dst));
 143                 return;
 144         }
 145         if (ip->ihl * 4 > len) {
 146                 add_note(wt, MSG_DEBUG, "Truncated IP header (ihl=%u len=%u) "
 147                          "in IPv4 packet (bssid=" MACSTR " str=" MACSTR
 148                          " dst=" MACSTR ")", ip->ihl, (unsigned) len,
 149                          MAC2STR(bssid), MAC2STR(src), MAC2STR(dst));
 150                 return;
 151         }
 152
 153         /* TODO: check header checksum in ip->check */
 154
 155         frag_off = be_to_host16(ip->frag_off);
 156         if (frag_off & 0x1fff) {
 157                 wpa_printf(MSG_EXCESSIVE, "IP fragment reassembly not yet "
 158                            "supported");
 159                 return;
 160         }
 161
 162         tot_len = be_to_host16(ip->tot_len);
 163         if (tot_len > len)
 164                 return;
 165         if (tot_len < len)
 166                 len = tot_len;
 167
 168         payload = data + 4 * ip->ihl;
 169         plen = len - 4 * ip->ihl;
 170
 171         switch (ip->protocol) {
 172         case IPPROTO_ICMP:
 173                 rx_data_icmp(wt, bssid, sta_addr, ip->daddr, ip->saddr,
 174                              payload, plen, peer_addr);
 175                 break;
 176         }
 177 }