i386/MIT/course/src/git.lab/net/testinput.c

   1 #include "ns.h"
   2 #include <netif/etharp.h>
   3
   4 static envid_t output_envid;
   5 static envid_t input_envid;
   6
   7 static struct jif_pkt *pkt = (struct jif_pkt*)REQVA;
   8
   9
  10 static void
  11 announce(void)
  12 {
  13         // We need to pre-announce our IP so we don't have to deal
  14         // with ARP requests.  Ideally, we would use gratuitous ARP
  15         // for this, but QEMU's ARP implementation is dumb and only
  16         // listens for very specific ARP requests, such as requests
  17         // for the gateway IP.
  18
  19         uint8_t mac[6] = {0x52, 0x54, 0x00, 0x12, 0x34, 0x56};
  20         uint32_t myip = inet_addr(IP);
  21         uint32_t gwip = inet_addr(DEFAULT);
  22         int r;
  23
  24         if ((r = sys_page_alloc(0, pkt, PTE_P|PTE_U|PTE_W)) < 0)
  25                 panic("sys_page_map: %e", r);
  26
  27         struct etharp_hdr *arp = (struct etharp_hdr*)pkt->jp_data;
  28         pkt->jp_len = sizeof(*arp);
  29
  30         memset(arp->ethhdr.dest.addr, 0xff, ETHARP_HWADDR_LEN);
  31         memcpy(arp->ethhdr.src.addr,  mac,  ETHARP_HWADDR_LEN);
  32         arp->ethhdr.type = htons(ETHTYPE_ARP);
  33         arp->hwtype = htons(1); // Ethernet
  34         arp->proto = htons(ETHTYPE_IP);
  35         arp->_hwlen_protolen = htons((ETHARP_HWADDR_LEN << 8) | 4);
  36         arp->opcode = htons(ARP_REQUEST);
  37         memcpy(arp->shwaddr.addr,  mac,   ETHARP_HWADDR_LEN);
  38         memcpy(arp->sipaddr.addrw, &myip, 4);
  39         memset(arp->dhwaddr.addr,  0x00,  ETHARP_HWADDR_LEN);
  40         memcpy(arp->dipaddr.addrw, &gwip, 4);
  41
  42         ipc_send(output_envid, NSREQ_OUTPUT, pkt, PTE_P|PTE_W|PTE_U);
  43         sys_page_unmap(0, pkt);
  44 }
  45
  46 static void
  47 hexdump(const char *prefix, const void *data, int len)
  48 {
  49         int i;
  50         char buf[80];
  51         char *end = buf + sizeof(buf);
  52         char *out = NULL;
  53         for (i = 0; i < len; i++) {
  54                 if (i % 16 == 0)
  55                         out = buf + snprintf(buf, end - buf,
  56                                              "%s%04x   ", prefix, i);
  57                 out += snprintf(out, end - out, "%02x", ((uint8_t*)data)[i]);
  58                 if (i % 16 == 15 || i == len - 1)
  59                         cprintf("%.*s\n", out - buf, buf);
  60                 if (i % 2 == 1)
  61                         *(out++) = ' ';
  62                 if (i % 16 == 7)
  63                         *(out++) = ' ';
  64         }
  65 }
  66
  67 void
  68 umain(int argc, char **argv)
  69 {
  70         envid_t ns_envid = sys_getenvid();
  71         int i, r, first = 1;
  72
  73         binaryname = "testinput";
  74
  75         output_envid = fork();
  76         if (output_envid < 0)
  77                 panic("error forking");
  78         else if (output_envid == 0) {
  79                 output(ns_envid);
  80                 return;
  81         }
  82
  83         input_envid = fork();
  84         if (input_envid < 0)
  85                 panic("error forking");
  86         else if (input_envid == 0) {
  87                 input(ns_envid);
  88                 return;
  89         }
  90
  91         cprintf("Sending ARP announcement...\n");
  92         announce();
  93
  94         while (1) {
  95                 envid_t whom;
  96                 int perm;
  97
  98                 int32_t req = ipc_recv((int32_t *)&whom, pkt, &perm);
  99                 if (req < 0)
 100                         panic("ipc_recv: %e", req);
 101                 if (whom != input_envid)
 102                         panic("IPC from unexpected environment %08x", whom);
 103                 if (req != NSREQ_INPUT)
 104                         panic("Unexpected IPC %d", req);
 105
 106                 hexdump("input: ", pkt->jp_data, pkt->jp_len);
 107                 cprintf("\n");
 108
 109                 // Only indicate that we're waiting for packets once
 110                 // we've received the ARP reply
 111                 if (first)
 112                         cprintf("Waiting for packets...\n");
 113                 first = 0;
 114         }
 115 }