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Simon Glass authored
Rename this function so that it is clear that it is provided by the RTC. Also return an error when it cannot function as expected. This is unlikely to occur since it works for dates since 1752 and many RTCs do not support such old dates. Still it is better to be accurate. Signed-off-by:
Simon Glass <sjg@chromium.org> Acked-by:
Heiko Schocher <hs@denx.de>
Simon Glass authoredRename this function so that it is clear that it is provided by the RTC. Also return an error when it cannot function as expected. This is unlikely to occur since it works for dates since 1752 and many RTCs do not support such old dates. Still it is better to be accurate. Signed-off-by:
Simon Glass <sjg@chromium.org> Acked-by:
Heiko Schocher <hs@denx.de>
dns.c 4.78 KiB
/*
* DNS support driver
*
* Copyright (c) 2008 Pieter Voorthuijsen <pieter.voorthuijsen@prodrive.nl>
* Copyright (c) 2009 Robin Getz <rgetz@blackfin.uclinux.org>
*
* This is a simple DNS implementation for U-Boot. It will use the first IP
* in the DNS response as net_server_ip. This can then be used for any other
* network related activities.
*
* The packet handling is partly based on TADNS, original copyrights
* follow below.
*
*/
/*
* Copyright (c) 2004-2005 Sergey Lyubka <valenok@gmail.com>
*
* "THE BEER-WARE LICENSE" (Revision 42):
* Sergey Lyubka wrote this file. As long as you retain this notice you
* can do whatever you want with this stuff. If we meet some day, and you think
* this stuff is worth it, you can buy me a beer in return.
*/
#include <common.h>
#include <command.h>
#include <net.h>
#include <asm/unaligned.h>
#include "dns.h"
char *net_dns_resolve; /* The host to resolve */
char *net_dns_env_var; /* The envvar to store the answer in */
static int dns_our_port;
static void dns_send(void)
{
struct header *header;
int n, name_len;
uchar *p, *pkt;
const char *s;
const char *name;
enum dns_query_type qtype = DNS_A_RECORD;
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->tid = 1;
header->flags = htons(0x100); /* standard query */
header->nqueries = htons(1); /* Just one query */
header->nanswers = 0;
header->nauth = 0;
header->nother = 0;
/* Encode DNS name */
name_len = strlen(name);
p = (uchar *)&header->data; /* For encoding host name into packet */
do {
s = strchr(name, '.');
if (!s)
s = name + name_len;
n = s - name; /* Chunk length */
*p++ = n; /* Copy length */
memcpy(p, name, n); /* Copy chunk */
p += n;
if (*s == '.')
n++;
name += n;
name_len -= n;
} while (*s != '\0');
*p++ = 0; /* Mark end of host name */
*p++ = 0; /* Some servers require double null */
*p++ = (unsigned char) qtype; /* Query Type */
*p++ = 0;
*p++ = 1; /* Class: inet, 0x0001 */
n = p - pkt; /* Total packet length */
debug("Packet size %d\n", n);
dns_our_port = random_port();
net_send_udp_packet(net_server_ethaddr, net_dns_server,
DNS_SERVICE_PORT, dns_our_port, n);
debug("DNS packet sent\n");
}
static void dns_timeout_handler(void)
{
puts("Timeout\n");
net_set_state(NETLOOP_FAIL);
}
static void dns_handler(uchar *pkt, unsigned dest, struct in_addr sip,
unsigned src, unsigned len)
{
struct header *header;
const unsigned char *p, *e, *s;
u16 type, i;
int found, stop, dlen;
char ip_str[22];
struct in_addr ip_addr;
debug("%s\n", __func__);
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]);
/* We sent one query. We want to have a single answer: */
header = (struct header *)pkt;
if (ntohs(header->nqueries) != 1)
return;
/* Received 0 answers */
if (header->nanswers == 0) {
puts("DNS: host not found\n");
net_set_state(NETLOOP_SUCCESS);
return;
}
/* Skip host name */
s = &header->data[0];
e = pkt + len;
for (p = s; p < e && *p != '\0'; p++)
continue;
/* We sent query class 1, query type 1 */
if (&p[5] > e || get_unaligned_be16(p+1) != DNS_A_RECORD) {
puts("DNS: response was not an A record\n");
net_set_state(NETLOOP_SUCCESS);
return;
}
/* Go to the first answer section */
p += 5;
/* 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++;
p--;
}
debug("Name (Offset in header): %d\n", p[1]);
type = get_unaligned_be16(p+2);
debug("type = %d\n", type);
if (type == DNS_CNAME_RECORD) {
/* CNAME answer. shift to the next section */
debug("Found canonical name\n");
dlen = get_unaligned_be16(p+10);
debug("dlen = %d\n", dlen);
p += 12 + dlen;
} else if (type == DNS_A_RECORD) {
debug("Found A-record\n");
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, ip_str);
printf("%s\n", ip_str);
if (net_dns_env_var)
setenv(net_dns_env_var, ip_str);
} else {
puts("server responded with invalid IP number\n");
}
}
net_set_state(NETLOOP_SUCCESS);
}
void dns_start(void)
{
debug("%s\n", __func__);
NetSetTimeout(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));
dns_send();
}