mirror of
https://github.com/logicog/RTLPlayground.git
synced 2026-10-29 17:54:14 +08:00
DrDoof
67b8c718fb
A small resolver for IPv4 address records, so that clients such as NTP can be given a host name: "dns server <ip> [<ip>]", "dns lookup <name>" and "dns". Without a configured server it uses the one DHCP handed out. A query goes to the servers in turn every two seconds and gives up after six tries; answers with compressed names and CNAME records ahead of the address are understood. A name that already is a dotted address is taken without a query. The resolver sits in BANK3, the command line in BANK2 next to the helpers it uses. The System page shows and sets the servers.
64 lines
1.5 KiB
C
64 lines
1.5 KiB
C
/*
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* Command line interface of the DNS resolver for the RTL837x platform
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* This code is in the Public Domain
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*/
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#include <stdint.h>
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#include "rtl837x_common.h"
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#include "cmd_parser.h"
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#include "dns.h"
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#pragma codeseg BANK2
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#pragma constseg BANK2
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extern __xdata uint8_t cmd_buffer[CMD_BUF_SIZE];
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extern __xdata uint8_t cmd_words_len;
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extern __xdata uint8_t cmd_words_b[15];
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extern __xdata uint8_t ip[4];
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uint8_t cmd_compare(uint8_t start, __code const uint8_t * cmd);
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uint8_t parse_ip(uint8_t idx);
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void dns_parse(void) __banked __reentrant
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{
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__xdata uint8_t *s;
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uint8_t n;
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if (cmd_words_len < 2) {
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dns_show();
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return;
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}
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if (cmd_compare(1, "server") && cmd_words_len >= 3 && parse_ip(cmd_words_b[2])) {
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memcpy(dns_state.server[0], ip, 4);
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memset(dns_state.server[1], 0, 4);
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if (cmd_words_len >= 4) {
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if (!parse_ip(cmd_words_b[3]))
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goto err;
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memcpy(dns_state.server[1], ip, 4);
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}
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return;
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}
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if (cmd_compare(1, "lookup") && cmd_words_len >= 3) {
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if (dns_state.status == DNS_PENDING) {
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print_string("DNS: a lookup is already running\n");
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return;
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}
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s = &cmd_buffer[cmd_words_b[2]];
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for (n = 0; s[n] && s[n] != ' '; n++) {
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if (n == DNS_NAME_LEN - 1)
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goto err;
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dns_state.name[n] = s[n];
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}
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dns_state.name[n] = 0;
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dns_state.verbose = 1;
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dns_lookup();
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if (dns_state.status == DNS_DONE) {
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print_ip(dns_state.addr);
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write_char('\n');
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}
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return;
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}
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err:
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print_string("Error: dns [server <ip> [<ip>]|lookup <name>]\n");
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}
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