#include <common.h>
#include <command.h>
+#include <env.h>
+#include <log.h>
#include <net.h>
#include <asm/unaligned.h>
#include "dns.h"
-char *NetDNSResolve; /* The host to resolve */
-char *NetDNSenvvar; /* The envvar to store the answer in */
+char *net_dns_resolve; /* The host to resolve */
+char *net_dns_env_var; /* The envvar to store the answer in */
-static int DnsOurPort;
+static int dns_our_port;
-static void
-DnsSend(void)
+/*
+ * make port a little random (1024-17407)
+ * This keeps the math somewhat trivial to compute, and seems to work with
+ * all supported protocols/clients/servers
+ */
+static unsigned int random_port(void)
+{
+ return 1024 + (get_timer(0) % 0x4000);
+}
+
+static void dns_send(void)
{
struct header *header;
int n, name_len;
const char *name;
enum dns_query_type qtype = DNS_A_RECORD;
- name = NetDNSResolve;
+ name = net_dns_resolve;
pkt = (uchar *)(net_tx_packet + net_eth_hdr_size() + IP_UDP_HDR_SIZE);
p = pkt;
/* Prepare DNS packet header */
- header = (struct header *) pkt;
+ header = (struct header *)pkt;
header->tid = 1;
header->flags = htons(0x100); /* standard query */
header->nqueries = htons(1); /* Just one query */
/* Encode DNS name */
name_len = strlen(name);
- p = (uchar *) &header->data; /* For encoding host name into packet */
+ p = (uchar *)&header->data; /* For encoding host name into packet */
do {
s = strchr(name, '.');
n = p - pkt; /* Total packet length */
debug("Packet size %d\n", n);
- DnsOurPort = random_port();
+ dns_our_port = random_port();
net_send_udp_packet(net_server_ethaddr, net_dns_server,
- DNS_SERVICE_PORT, DnsOurPort, n);
+ DNS_SERVICE_PORT, dns_our_port, n);
debug("DNS packet sent\n");
}
-static void
-DnsTimeout(void)
+static void dns_timeout_handler(void)
{
puts("Timeout\n");
net_set_state(NETLOOP_FAIL);
const unsigned char *p, *e, *s;
u16 type, i;
int found, stop, dlen;
- char IPStr[22];
+ char ip_str[22];
struct in_addr ip_addr;
debug("%s\n", __func__);
- if (dest != DnsOurPort)
+ if (dest != dns_our_port)
return;
for (i = 0; i < len; i += 4)
debug("0x%p - 0x%.2x 0x%.2x 0x%.2x 0x%.2x\n",
- pkt+i, pkt[i], pkt[i+1], pkt[i+2], pkt[i+3]);
+ pkt+i, pkt[i], pkt[i+1], pkt[i+2], pkt[i+3]);
/* We sent one query. We want to have a single answer: */
- header = (struct header *) pkt;
+ header = (struct header *)pkt;
if (ntohs(header->nqueries) != 1)
return;
/* Loop through the answers, we want A type answer */
for (found = stop = 0; !stop && &p[12] < e; ) {
-
/* Skip possible name in CNAME answer */
if (*p != 0xc0) {
while (*p && &p[12] < e)
p += 12 + dlen;
} else if (type == DNS_A_RECORD) {
debug("Found A-record\n");
- found = stop = 1;
+ found = 1;
+ stop = 1;
} else {
debug("Unknown type\n");
stop = 1;
}
if (found && &p[12] < e) {
-
dlen = get_unaligned_be16(p+10);
p += 12;
memcpy(&ip_addr, p, 4);
if (p + dlen <= e) {
- ip_to_string(ip_addr, IPStr);
- printf("%s\n", IPStr);
- if (NetDNSenvvar)
- setenv(NetDNSenvvar, IPStr);
- } else
+ ip_to_string(ip_addr, ip_str);
+ printf("%s\n", ip_str);
+ if (net_dns_env_var)
+ env_set(net_dns_env_var, ip_str);
+ } else {
puts("server responded with invalid IP number\n");
+ }
}
net_set_state(NETLOOP_SUCCESS);
}
-void
-DnsStart(void)
+void dns_start(void)
{
debug("%s\n", __func__);
- NetSetTimeout(DNS_TIMEOUT, DnsTimeout);
+ net_set_timeout_handler(DNS_TIMEOUT, dns_timeout_handler);
net_set_udp_handler(dns_handler);
/* Clear a previous MAC address, the server IP might have changed. */
memset(net_server_ethaddr, 0, sizeof(net_server_ethaddr));
- DnsSend();
+ dns_send();
}