diff options
Diffstat (limited to 'rfc1035/rfc1035.c')
| -rw-r--r-- | rfc1035/rfc1035.c | 496 |
1 files changed, 496 insertions, 0 deletions
diff --git a/rfc1035/rfc1035.c b/rfc1035/rfc1035.c new file mode 100644 index 0000000..0e3678b --- /dev/null +++ b/rfc1035/rfc1035.c @@ -0,0 +1,496 @@ +/* +** Copyright 1998 - 2011 Double Precision, Inc. +** See COPYING for distribution information. +*/ + +#include "config.h" +#include <stdio.h> +#include "soxwrap/soxwrap.h" +#include <stdlib.h> +#include <string.h> +#include <errno.h> +#include <sys/types.h> +#if TIME_WITH_SYS_TIME +#include <sys/time.h> +#include <time.h> +#else +#if HAVE_SYS_TIME_H +#include <sys/time.h> +#else +#include <time.h> +#endif +#endif +#include <arpa/inet.h> +#if HAVE_UNISTD_H +#include <unistd.h> +#endif + +#include "rfc1035.h" + + +#define ISSPACE(c) (strchr(" \t\r\n", (int)(unsigned char)(c)) != NULL) + +#if RFC1035_IPV6 + +#else + +struct in_addr rfc1035_addr_any={INADDR_ANY}; + +#endif + +void rfc1035_init_timeout(struct rfc1035_res *res, unsigned s, unsigned n) +{ + res->rfc1035_timeout_initial=s; + res->rfc1035_timeout_backoff=n; +} + +void rfc1035_init_ns(struct rfc1035_res *res, const RFC1035_ADDR *a, unsigned n) +{ +unsigned i; +unsigned j; + + j=0; + + random128_binary(&res->randseed); + md5_digest(&res->randseed, sizeof(res->randseed), res->randbuf); + res->randptr=0; + + for (i=0; i == 0 || (i<n && i<RFC1035_MAXNS); i++) + { +#if RFC1035_IPV6 + struct in6_addr sin; + + if (n == 0) + sin=in6addr_loopback; + else + sin=a[(j+i)%n]; + +#else + struct in_addr sin; + + if (n == 0) + { + rfc1035_aton("127.0.0.1", &sin); + } + else + sin=a[(j+i)%n]; + memset(&res->nameservers[i], 0, sizeof(res->nameservers[i])); + res->nameservers[i]=sin; +#endif + res->nameservers[i]=sin; + } + res->rfc1035_nnameservers=i; + +} + +int rfc1035_init_defaultdomain(struct rfc1035_res *res, const char *p) +{ +char *q; + + if (res->rfc1035_defaultdomain) + free(res->rfc1035_defaultdomain); + + if ((res->rfc1035_defaultdomain=malloc(strlen(p)+1)) == 0) + return (-1); + + strcpy(res->rfc1035_defaultdomain, p); + for (q=res->rfc1035_defaultdomain; *q; q++) + if (ISSPACE(*q)) + { + *q=0; + break; + } + + return (0); +} + +void rfc1035_init_dnssec_enable(struct rfc1035_res *res, int flag) +{ + rfc1035_init_edns_payload(res, flag ? 1280:0); +} + + +void rfc1035_init_edns_payload(struct rfc1035_res *res, int payload_size) +{ + res->dnssec_payload_size=payload_size; +} + +static char tl(char c) +{ + if (c >= 'A' && c <= 'Z') + c += 'a' - 'A'; + + return c; +} + +void rfc1035_init_resolv(struct rfc1035_res *res) +{ +FILE *fp=fopen("/etc/resolv.conf", "r"); +char rfc1035_buf[512]; +RFC1035_ADDR ns[RFC1035_MAXNS]; +int nns=0; + + memset(res, 0, sizeof(*res)); + + while (fp && fgets(rfc1035_buf, sizeof(rfc1035_buf), fp)) + { + char *p; + + for (p=rfc1035_buf; *p; p++) + *p=tl(*p); + + for (p=rfc1035_buf; *p; p++) + if (ISSPACE(*p)) break; + if (*p) *p++=0; + + if (strcmp(rfc1035_buf, "domain") == 0) + { + while (p && ISSPACE(*p)) + ++p; + rfc1035_init_defaultdomain(res, p); + continue; + } + + if (strcmp(rfc1035_buf, "nameserver")) continue; + while (*p && ISSPACE(*p)) p++; + if (nns < RFC1035_MAXNS) + { + char *q; + + for (q=p; *q && !ISSPACE(*q); q++) + ; + *q=0; + + if (rfc1035_aton(p, &ns[nns++]) < 0) + --nns; + } + } + if (fp) fclose(fp); + + rfc1035_init_ns(res, ns, nns); +} + +void rfc1035_destroy_resolv(struct rfc1035_res *res) +{ + if (res->rfc1035_defaultdomain) + { + free(res->rfc1035_defaultdomain); + } +} + +/************/ + +struct compresslist { + struct compresslist *next; + unsigned offset; + const char *ptr; + } ; + +static int mkpacketq(void (*)(const char *, unsigned, void *), void *, + unsigned *, + const struct rfc1035_query *, + unsigned, + const char *, + struct compresslist *, + struct rfc1035_res *); + +unsigned rfc1035_next_randid(struct rfc1035_res *res) +{ + unsigned i; + + if (res->randptr >= sizeof(res->randbuf)) + { + for (i=0; i<sizeof(res->randseed); i++) + if ( ++((unsigned char *)res->randseed)[i]) + break; + + md5_digest(res->randseed, sizeof(res->randseed), + res->randbuf); + res->randptr=0; + } + + i= ((unsigned)((unsigned char *)res->randbuf)[res->randptr] << 8) | + ((unsigned char *)res->randbuf)[res->randptr+1]; + res->randptr += 2; + return i; +} + +int rfc1035_mkquery(struct rfc1035_res *res, /* resolver */ + unsigned opcode, /* opcode */ + const struct rfc1035_query *questions, + unsigned nquestions, + void (*func)(const char *, unsigned, void *), void *arg) +{ +struct { + unsigned char idhi, idlo; + unsigned char infohi, infolo; + unsigned char qhi, qlo; + unsigned char ahi, alo; + unsigned char nhi, nlo; + unsigned char auhi, aulo; + } header; +unsigned cnt; + + unsigned id=rfc1035_next_randid(res); + + header.idhi= id >> 8; + header.idlo= id; + + header.infohi= (opcode << 3) & 0x78; + + if (!res->norecursive) + header.infohi |= 1; /* Want a recursive query */ + header.infolo=0; + header.qhi=nquestions >> 8; + header.qlo=nquestions; + header.ahi=0; + header.alo=0; + header.nhi=0; + header.nlo=0; + header.auhi=0; + header.aulo=0; + + if (res->dnssec_payload_size) + header.aulo=1; + + (*func)( (const char *)&header, sizeof(header), arg); + cnt=sizeof(header); + if (nquestions) + if (mkpacketq(func, arg, &cnt, questions, nquestions, + questions->name, 0, res)) return (-1); + + if (res->dnssec_payload_size) + { + /* RFC 2671, section 4.3 */ + + struct { + char opt_root_domain_name; + char opt_type_hi; + char opt_type_lo; + char opt_class_hi; + char opt_class_lo; + char opt_extendedrcode; + char opt_version; + char opt_ttl_zhi; + char opt_ttl_zlo; + char opt_rdlen_hi; + char opt_rdlen_lo; + } rfc2671_43; + + memset(&rfc2671_43, 0, sizeof(rfc2671_43)); + + rfc2671_43.opt_type_lo=RFC1035_TYPE_OPT; + + rfc2671_43.opt_class_hi= res->dnssec_payload_size >> 8; + rfc2671_43.opt_class_lo= res->dnssec_payload_size; + rfc2671_43.opt_ttl_zhi |= 0x80; /* RFC 3225 */ + + (*func)((char *)&rfc2671_43, sizeof(rfc2671_43), arg); + } + + return (0); +} + +int rfc1035_hostnamecmp(const char *p, const char *q) +{ + while (*p || *q) + { + if (*p == '.' || *q == '.' ) + { + if ( (*p && *p != '.') || (*q && *q != '.')) + return (1); + while (*p == '.') ++p; + while (*q == '.') ++q; + continue; + } + if (!*p || !*q) return (1); + if ( tl(*p) != tl(*q)) return (1); + ++p; + ++q; + } + return (0); +} + +static struct compresslist *search(struct compresslist *cp, const char *name) +{ + for ( ; cp; cp=cp->next) + { + if (rfc1035_hostnamecmp(name, cp->ptr) == 0 && + (cp->offset & 0x3FFF) == cp->offset) + return (cp); + /* Packet compression uses the two high bits */ + } + return (0); +} + +static int mkpacketq_full(void (*)(const char *, unsigned, void *), + void *, + unsigned *, + const struct rfc1035_query *, + unsigned, + const char *, + struct compresslist *, struct rfc1035_res *); + +static int mkpacketq(void (*func)(const char *, unsigned, void *), void *arg, + unsigned *cnt, + const struct rfc1035_query *qp, + unsigned nqp, + const char *nameptr, + struct compresslist *comp_list, + struct rfc1035_res *res) +{ +char *buf; +int rc; + + + if (!res->rfc1035_defaultdomain || strchr(nameptr, '.')) + return (mkpacketq_full(func, arg, cnt, qp, nqp, nameptr, + comp_list, res)); + + /* Append default domain */ + + if ((buf=malloc(strlen(nameptr)+ + strlen(res->rfc1035_defaultdomain)+2)) == 0) + return (-1); + + strcat(strcat(strcpy(buf, nameptr), "."), + res->rfc1035_defaultdomain); + + rc=mkpacketq_full(func, arg, cnt, qp, nqp, buf, comp_list, res); + free(buf); + return (rc); +} + +static int mkpacketq_full(void (*func)(const char *, unsigned, void *), + void *arg, + unsigned *cnt, + const struct rfc1035_query *qp, + unsigned nqp, + const char *nameptr, + struct compresslist *comp_list, + struct rfc1035_res *res) +{ +unsigned llen; +struct compresslist *cp; + + while (nameptr && *nameptr == '.') + ++nameptr; + + if (!nameptr || !*nameptr) + { + struct { + unsigned char padtail; + unsigned char qtypehi, qtypelo; + unsigned char qclasshi, qclasslo; + } qtail; + + qtail.padtail=0; + qtail.qtypehi=qp->qtype >> 8; + qtail.qtypelo=qp->qtype; + qtail.qclasshi=qp->qclass >> 8; + qtail.qclasslo=qp->qclass; + + (*func)((const char *)&qtail, sizeof(qtail), arg); + ++qp; + --nqp; + *cnt += sizeof(qtail); + if (nqp) + return (mkpacketq(func, arg, cnt, + qp, nqp, qp->name, comp_list, res)); + return (0); + } + + for (llen=0; nameptr[llen] && nameptr[llen] != '.'; llen++) + ; + cp=search(comp_list, nameptr); + if (cp) + { + struct { + unsigned char ptrhi, ptrlo; + unsigned char qtypehi, qtypelo; + unsigned char qclasshi, qclasslo; + } qtail; + + qtail.ptrhi= (cp->offset >> 8) | 0xC0; + qtail.ptrlo= cp->offset; + qtail.qtypehi=qp->qtype >> 8; + qtail.qtypelo=qp->qtype; + qtail.qclasshi=qp->qclass >> 8; + qtail.qclasslo=qp->qclass; + + (*func)( (const char *)&qtail, sizeof(qtail), arg); + ++qp; + --nqp; + *cnt += sizeof(qtail); + + if (nqp) + return (mkpacketq(func, arg, cnt, + qp, nqp, qp->name, comp_list, res)); + } + else + { + unsigned n=llen; + unsigned char c; + struct compresslist newc; + + if (n > 63) return (-1); + + newc.next=comp_list; + newc.offset= *cnt; + newc.ptr=nameptr; + + c=(unsigned char)n; + (*func)((const char *) &c, 1, arg); + (*func)( nameptr, c, arg); + *cnt += 1+c; + return (mkpacketq_full(func, arg, cnt, + qp, nqp, nameptr+llen, &newc, res)); + } + return (0); +} + +/*******************************************************/ + +int rfc1035_wait_reply(int fd, unsigned nsecs) +{ +fd_set fds; +struct timeval tv; +int n; + + FD_ZERO(&fds); + FD_SET(fd, &fds); + tv.tv_sec=nsecs; + tv.tv_usec=0; + while ((n=sox_select(fd+1, &fds, 0, 0, &tv)) < 0) + { + if (errno != EINTR) + break; + } + + if (n > 0 && FD_ISSET(fd, &fds)) + return (0); + errno=ETIMEDOUT; + return (-1); +} + +int rfc1035_wait_query(int fd, unsigned nsecs) +{ +fd_set fds; +struct timeval tv; +int n; + + FD_ZERO(&fds); + FD_SET(fd, &fds); + tv.tv_sec=nsecs; + tv.tv_usec=0; + while ((n=sox_select(fd+1, 0, &fds, 0, &tv)) < 0) + { + if (errno != EINTR) + break; + } + + if (n > 0 && FD_ISSET(fd, &fds)) + return (0); + errno=ETIMEDOUT; + return (-1); +} |