From 249866e3d1e11dc72eaa1305f4bb479ded92ef38 Mon Sep 17 00:00:00 2001 From: Jannis Hoffmann Date: Tue, 9 Jul 2024 13:58:20 +0200 Subject: reorganized file structure Moved c files into src/. Corrected VERSION file. Removed BUILD and FILES. --- src/dnsstub/dns_name.c | 80 ++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 80 insertions(+) create mode 100644 src/dnsstub/dns_name.c (limited to 'src/dnsstub/dns_name.c') diff --git a/src/dnsstub/dns_name.c b/src/dnsstub/dns_name.c new file mode 100644 index 0000000..0723a8f --- /dev/null +++ b/src/dnsstub/dns_name.c @@ -0,0 +1,80 @@ +#include "stralloc.h" +#include "uint_t.h" +#include "byte.h" +#include "ip.h" +#include "dnsresolv.h" + +/** + @file dns_name.c + @author djb, fefe, feh + @source ucspi-tcp + @brief DNS name query (ptr) +*/ + +static char *q = 0; + +int dns_name_packet(stralloc *out,const char *buf,unsigned int len) +{ + unsigned int pos; + char header[12]; + uint16 numanswers; + uint16 datalen; + + if (!stralloc_copys(out,"")) return DNS_MEM; + + pos = dns_packet_copy(buf,len,0,header,12); if (!pos) return DNS_ERR; + uint16_unpack_big(header + 6,&numanswers); + pos = dns_packet_skipname(buf,len,pos); if (!pos) return DNS_ERR; + pos += 4; + + while (numanswers--) { + pos = dns_packet_skipname(buf,len,pos); if (!pos) return DNS_ERR; + pos = dns_packet_copy(buf,len,pos,header,10); if (!pos) return DNS_ERR; + uint16_unpack_big(header + 8,&datalen); + if (byte_equal(header,2,DNS_T_PTR)) + if (byte_equal(header + 2,2,DNS_C_IN)) { + if (!dns_packet_getname(buf,len,pos,&q)) return DNS_ERR; + if (dns_domain_todot_cat(out,q) <= 0) return DNS_ERR; + return 1; + } + pos += datalen; + } + + return 0; +} + +int dns_name4(stralloc *out,const char ip[4]) +{ + int rc; + char name[DNS_NAME4_DOMAIN]; + + dns_name4_domain(name,ip); + if (dns_resolve(name,DNS_T_PTR) < 0) return DNS_ERR; + if ((rc = dns_name_packet(out,dns_resolve_tx.packet,dns_resolve_tx.packetlen)) < 0) return DNS_ERR; + dns_transmit_free(&dns_resolve_tx); + dns_domain_free(&q); + + return rc; +} + +int dns_name6(stralloc *out,const char ip[16]) +{ + int rc; + char name[DNS_NAME6_DOMAIN]; + + dns_name6_domain(name,ip); + if (dns_resolve(name,DNS_T_PTR) < 0) return DNS_ERR; + if ((rc = dns_name_packet(out,dns_resolve_tx.packet,dns_resolve_tx.packetlen)) < 0) return DNS_ERR; + dns_transmit_free(&dns_resolve_tx); + dns_domain_free(&q); + + return rc; +} + +int dns_name(stralloc *out,const char ip[16]) +{ + if (ip6_isv4mapped(ip)) + return dns_name4(out,ip+12); + else + return dns_name6(out,ip); +} -- cgit v1.2.3