From ed4a73a05d45f6ff49085f8c32ccd6e2a5759877 Mon Sep 17 00:00:00 2001 From: sunil Date: Sat, 6 Jan 2018 07:57:53 +0000 Subject: [PATCH] Move unpack functions into a seperate file. Required for upcoming 'smtpctl spf walk'. Ok eric@ gilles@ millert@ --- usr.sbin/smtpd/dns.c | 346 +--------------------------------- usr.sbin/smtpd/smtpd/Makefile | 3 +- usr.sbin/smtpd/unpack_dns.c | 295 +++++++++++++++++++++++++++++ usr.sbin/smtpd/unpack_dns.h | 96 ++++++++++ 4 files changed, 395 insertions(+), 345 deletions(-) create mode 100644 usr.sbin/smtpd/unpack_dns.c create mode 100644 usr.sbin/smtpd/unpack_dns.h diff --git a/usr.sbin/smtpd/dns.c b/usr.sbin/smtpd/dns.c index 0f12f9224a5..b5c13e61fae 100644 --- a/usr.sbin/smtpd/dns.c +++ b/usr.sbin/smtpd/dns.c @@ -1,4 +1,4 @@ -/* $OpenBSD: dns.c,v 1.84 2017/05/31 04:50:55 deraadt Exp $ */ +/* $OpenBSD: dns.c,v 1.85 2018/01/06 07:57:53 sunil Exp $ */ /* * Copyright (c) 2008 Gilles Chehade @@ -39,6 +39,7 @@ #include "smtpd.h" #include "log.h" +#include "unpack_dns.h" struct dns_lookup { struct dns_session *session; @@ -61,84 +62,6 @@ static void dns_dispatch_ptr(struct asr_result *, void *); static void dns_dispatch_mx(struct asr_result *, void *); static void dns_dispatch_mx_preference(struct asr_result *, void *); -struct unpack { - const char *buf; - size_t len; - size_t offset; - const char *err; -}; - -struct dns_header { - uint16_t id; - uint16_t flags; - uint16_t qdcount; - uint16_t ancount; - uint16_t nscount; - uint16_t arcount; -}; - -struct dns_query { - char q_dname[MAXDNAME]; - uint16_t q_type; - uint16_t q_class; -}; - -struct dns_rr { - char rr_dname[MAXDNAME]; - uint16_t rr_type; - uint16_t rr_class; - uint32_t rr_ttl; - union { - struct { - char cname[MAXDNAME]; - } cname; - struct { - uint16_t preference; - char exchange[MAXDNAME]; - } mx; - struct { - char nsname[MAXDNAME]; - } ns; - struct { - char ptrname[MAXDNAME]; - } ptr; - struct { - char mname[MAXDNAME]; - char rname[MAXDNAME]; - uint32_t serial; - uint32_t refresh; - uint32_t retry; - uint32_t expire; - uint32_t minimum; - } soa; - struct { - struct in_addr addr; - } in_a; - struct { - struct in6_addr addr6; - } in_aaaa; - struct { - uint16_t rdlen; - const void *rdata; - } other; - } rr; -}; - -static char *print_dname(const char *, char *, size_t); -static ssize_t dname_expand(const unsigned char *, size_t, size_t, size_t *, - char *, size_t); -static int unpack_data(struct unpack *, void *, size_t); -static int unpack_u16(struct unpack *, uint16_t *); -static int unpack_u32(struct unpack *, uint32_t *); -static int unpack_inaddr(struct unpack *, struct in_addr *); -static int unpack_in6addr(struct unpack *, struct in6_addr *); -static int unpack_dname(struct unpack *, char *, size_t); -static void unpack_init(struct unpack *, const char *, size_t); -static int unpack_header(struct unpack *, struct dns_header *); -static int unpack_query(struct unpack *, struct dns_query *); -static int unpack_rr(struct unpack *, struct dns_rr *); - - static int domainname_is_addr(const char *s, struct sockaddr *sa, socklen_t *sl) { @@ -462,268 +385,3 @@ dns_lookup_host(struct dns_session *s, const char *host, int preference) as = getaddrinfo_async(host, NULL, &hints, NULL); event_asr_run(as, dns_dispatch_host, lookup); } - -static char * -print_dname(const char *_dname, char *buf, size_t max) -{ - const unsigned char *dname = _dname; - char *res; - size_t left, n, count; - - if (_dname[0] == 0) { - (void)strlcpy(buf, ".", max); - return buf; - } - - res = buf; - left = max - 1; - for (n = 0; dname[0] && left; n += dname[0]) { - count = (dname[0] < (left - 1)) ? dname[0] : (left - 1); - memmove(buf, dname + 1, count); - dname += dname[0] + 1; - left -= count; - buf += count; - if (left) { - left -= 1; - *buf++ = '.'; - } - } - buf[0] = 0; - - return (res); -} - -static ssize_t -dname_expand(const unsigned char *data, size_t len, size_t offset, - size_t *newoffset, char *dst, size_t max) -{ - size_t n, count, end, ptr, start; - ssize_t res; - - if (offset >= len) - return (-1); - - res = 0; - end = start = offset; - - for (; (n = data[offset]); ) { - if ((n & 0xc0) == 0xc0) { - if (offset + 2 > len) - return (-1); - ptr = 256 * (n & ~0xc0) + data[offset + 1]; - if (ptr >= start) - return (-1); - if (end < offset + 2) - end = offset + 2; - offset = start = ptr; - continue; - } - if (offset + n + 1 > len) - return (-1); - - /* copy n + at offset+1 */ - if (dst != NULL && max != 0) { - count = (max < n + 1) ? (max) : (n + 1); - memmove(dst, data + offset, count); - dst += count; - max -= count; - } - res += n + 1; - offset += n + 1; - if (end < offset) - end = offset; - } - if (end < offset + 1) - end = offset + 1; - - if (dst != NULL && max != 0) - dst[0] = 0; - if (newoffset) - *newoffset = end; - return (res + 1); -} - -void -unpack_init(struct unpack *unpack, const char *buf, size_t len) -{ - unpack->buf = buf; - unpack->len = len; - unpack->offset = 0; - unpack->err = NULL; -} - -static int -unpack_data(struct unpack *p, void *data, size_t len) -{ - if (p->err) - return (-1); - - if (p->len - p->offset < len) { - p->err = "too short"; - return (-1); - } - - memmove(data, p->buf + p->offset, len); - p->offset += len; - - return (0); -} - -static int -unpack_u16(struct unpack *p, uint16_t *u16) -{ - if (unpack_data(p, u16, 2) == -1) - return (-1); - - *u16 = ntohs(*u16); - - return (0); -} - -static int -unpack_u32(struct unpack *p, uint32_t *u32) -{ - if (unpack_data(p, u32, 4) == -1) - return (-1); - - *u32 = ntohl(*u32); - - return (0); -} - -static int -unpack_inaddr(struct unpack *p, struct in_addr *a) -{ - return (unpack_data(p, a, 4)); -} - -static int -unpack_in6addr(struct unpack *p, struct in6_addr *a6) -{ - return (unpack_data(p, a6, 16)); -} - -static int -unpack_dname(struct unpack *p, char *dst, size_t max) -{ - ssize_t e; - - if (p->err) - return (-1); - - e = dname_expand(p->buf, p->len, p->offset, &p->offset, dst, max); - if (e == -1) { - p->err = "bad domain name"; - return (-1); - } - if (e < 0 || e > MAXDNAME) { - p->err = "domain name too long"; - return (-1); - } - - return (0); -} - -static int -unpack_header(struct unpack *p, struct dns_header *h) -{ - if (unpack_data(p, h, HFIXEDSZ) == -1) - return (-1); - - h->flags = ntohs(h->flags); - h->qdcount = ntohs(h->qdcount); - h->ancount = ntohs(h->ancount); - h->nscount = ntohs(h->nscount); - h->arcount = ntohs(h->arcount); - - return (0); -} - -static int -unpack_query(struct unpack *p, struct dns_query *q) -{ - unpack_dname(p, q->q_dname, sizeof(q->q_dname)); - unpack_u16(p, &q->q_type); - unpack_u16(p, &q->q_class); - - return (p->err) ? (-1) : (0); -} - -static int -unpack_rr(struct unpack *p, struct dns_rr *rr) -{ - uint16_t rdlen; - size_t save_offset; - - unpack_dname(p, rr->rr_dname, sizeof(rr->rr_dname)); - unpack_u16(p, &rr->rr_type); - unpack_u16(p, &rr->rr_class); - unpack_u32(p, &rr->rr_ttl); - unpack_u16(p, &rdlen); - - if (p->err) - return (-1); - - if (p->len - p->offset < rdlen) { - p->err = "too short"; - return (-1); - } - - save_offset = p->offset; - - switch (rr->rr_type) { - - case T_CNAME: - unpack_dname(p, rr->rr.cname.cname, sizeof(rr->rr.cname.cname)); - break; - - case T_MX: - unpack_u16(p, &rr->rr.mx.preference); - unpack_dname(p, rr->rr.mx.exchange, sizeof(rr->rr.mx.exchange)); - break; - - case T_NS: - unpack_dname(p, rr->rr.ns.nsname, sizeof(rr->rr.ns.nsname)); - break; - - case T_PTR: - unpack_dname(p, rr->rr.ptr.ptrname, sizeof(rr->rr.ptr.ptrname)); - break; - - case T_SOA: - unpack_dname(p, rr->rr.soa.mname, sizeof(rr->rr.soa.mname)); - unpack_dname(p, rr->rr.soa.rname, sizeof(rr->rr.soa.rname)); - unpack_u32(p, &rr->rr.soa.serial); - unpack_u32(p, &rr->rr.soa.refresh); - unpack_u32(p, &rr->rr.soa.retry); - unpack_u32(p, &rr->rr.soa.expire); - unpack_u32(p, &rr->rr.soa.minimum); - break; - - case T_A: - if (rr->rr_class != C_IN) - goto other; - unpack_inaddr(p, &rr->rr.in_a.addr); - break; - - case T_AAAA: - if (rr->rr_class != C_IN) - goto other; - unpack_in6addr(p, &rr->rr.in_aaaa.addr6); - break; - default: - other: - rr->rr.other.rdata = p->buf + p->offset; - rr->rr.other.rdlen = rdlen; - p->offset += rdlen; - } - - if (p->err) - return (-1); - - /* make sure that the advertised rdlen is really ok */ - if (p->offset - save_offset != rdlen) - p->err = "bad dlen"; - - return (p->err) ? (-1) : (0); -} diff --git a/usr.sbin/smtpd/smtpd/Makefile b/usr.sbin/smtpd/smtpd/Makefile index a7621419118..b193c34e17e 100644 --- a/usr.sbin/smtpd/smtpd/Makefile +++ b/usr.sbin/smtpd/smtpd/Makefile @@ -1,4 +1,4 @@ -# $OpenBSD: Makefile,v 1.88 2017/08/13 11:10:31 eric Exp $ +# $OpenBSD: Makefile,v 1.89 2018/01/06 07:57:53 sunil Exp $ .PATH: ${.CURDIR}/.. @@ -14,6 +14,7 @@ SRCS+= crypto.c SRCS+= delivery.c SRCS+= dict.c SRCS+= dns.c +SRCS+= unpack_dns.c SRCS+= envelope.c SRCS+= esc.c SRCS+= expand.c diff --git a/usr.sbin/smtpd/unpack_dns.c b/usr.sbin/smtpd/unpack_dns.c new file mode 100644 index 00000000000..fe50b026cb7 --- /dev/null +++ b/usr.sbin/smtpd/unpack_dns.c @@ -0,0 +1,295 @@ +/* $OpenBSD: unpack_dns.c,v 1.1 2018/01/06 07:57:53 sunil Exp $ */ + +/* + * Copyright (c) 2011-2014 Eric Faurot + * + * Permission to use, copy, modify, and distribute this software for any + * purpose with or without fee is hereby granted, provided that the above + * copyright notice and this permission notice appear in all copies. + * + * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES + * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF + * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR + * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES + * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN + * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF + * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. + */ + +#include + +#include + +#include "unpack_dns.h" + +static int unpack_data(struct unpack *, void *, size_t); +static int unpack_u16(struct unpack *, uint16_t *); +static int unpack_u32(struct unpack *, uint32_t *); +static int unpack_inaddr(struct unpack *, struct in_addr *); +static int unpack_in6addr(struct unpack *, struct in6_addr *); +static int unpack_dname(struct unpack *, char *, size_t); + +void +unpack_init(struct unpack *unpack, const char *buf, size_t len) +{ + unpack->buf = buf; + unpack->len = len; + unpack->offset = 0; + unpack->err = NULL; +} + +int +unpack_header(struct unpack *p, struct dns_header *h) +{ + if (unpack_data(p, h, HFIXEDSZ) == -1) + return (-1); + + h->flags = ntohs(h->flags); + h->qdcount = ntohs(h->qdcount); + h->ancount = ntohs(h->ancount); + h->nscount = ntohs(h->nscount); + h->arcount = ntohs(h->arcount); + + return (0); +} + +int +unpack_query(struct unpack *p, struct dns_query *q) +{ + unpack_dname(p, q->q_dname, sizeof(q->q_dname)); + unpack_u16(p, &q->q_type); + unpack_u16(p, &q->q_class); + + return (p->err) ? (-1) : (0); +} + +int +unpack_rr(struct unpack *p, struct dns_rr *rr) +{ + uint16_t rdlen; + size_t save_offset; + + unpack_dname(p, rr->rr_dname, sizeof(rr->rr_dname)); + unpack_u16(p, &rr->rr_type); + unpack_u16(p, &rr->rr_class); + unpack_u32(p, &rr->rr_ttl); + unpack_u16(p, &rdlen); + + if (p->err) + return (-1); + + if (p->len - p->offset < rdlen) { + p->err = "too short"; + return (-1); + } + + save_offset = p->offset; + + switch (rr->rr_type) { + + case T_CNAME: + unpack_dname(p, rr->rr.cname.cname, sizeof(rr->rr.cname.cname)); + break; + + case T_MX: + unpack_u16(p, &rr->rr.mx.preference); + unpack_dname(p, rr->rr.mx.exchange, sizeof(rr->rr.mx.exchange)); + break; + + case T_NS: + unpack_dname(p, rr->rr.ns.nsname, sizeof(rr->rr.ns.nsname)); + break; + + case T_PTR: + unpack_dname(p, rr->rr.ptr.ptrname, sizeof(rr->rr.ptr.ptrname)); + break; + + case T_SOA: + unpack_dname(p, rr->rr.soa.mname, sizeof(rr->rr.soa.mname)); + unpack_dname(p, rr->rr.soa.rname, sizeof(rr->rr.soa.rname)); + unpack_u32(p, &rr->rr.soa.serial); + unpack_u32(p, &rr->rr.soa.refresh); + unpack_u32(p, &rr->rr.soa.retry); + unpack_u32(p, &rr->rr.soa.expire); + unpack_u32(p, &rr->rr.soa.minimum); + break; + + case T_A: + if (rr->rr_class != C_IN) + goto other; + unpack_inaddr(p, &rr->rr.in_a.addr); + break; + + case T_AAAA: + if (rr->rr_class != C_IN) + goto other; + unpack_in6addr(p, &rr->rr.in_aaaa.addr6); + break; + default: + other: + rr->rr.other.rdata = p->buf + p->offset; + rr->rr.other.rdlen = rdlen; + p->offset += rdlen; + } + + if (p->err) + return (-1); + + /* make sure that the advertised rdlen is really ok */ + if (p->offset - save_offset != rdlen) + p->err = "bad dlen"; + + return (p->err) ? (-1) : (0); +} + +ssize_t +dname_expand(const unsigned char *data, size_t len, size_t offset, + size_t *newoffset, char *dst, size_t max) +{ + size_t n, count, end, ptr, start; + ssize_t res; + + if (offset >= len) + return (-1); + + res = 0; + end = start = offset; + + for (; (n = data[offset]); ) { + if ((n & 0xc0) == 0xc0) { + if (offset + 2 > len) + return (-1); + ptr = 256 * (n & ~0xc0) + data[offset + 1]; + if (ptr >= start) + return (-1); + if (end < offset + 2) + end = offset + 2; + offset = start = ptr; + continue; + } + if (offset + n + 1 > len) + return (-1); + + /* copy n + at offset+1 */ + if (dst != NULL && max != 0) { + count = (max < n + 1) ? (max) : (n + 1); + memmove(dst, data + offset, count); + dst += count; + max -= count; + } + res += n + 1; + offset += n + 1; + if (end < offset) + end = offset; + } + if (end < offset + 1) + end = offset + 1; + + if (dst != NULL && max != 0) + dst[0] = 0; + if (newoffset) + *newoffset = end; + return (res + 1); +} + +char * +print_dname(const char *_dname, char *buf, size_t max) +{ + const unsigned char *dname = _dname; + char *res; + size_t left, n, count; + + if (_dname[0] == 0) { + (void)strlcpy(buf, ".", max); + return buf; + } + + res = buf; + left = max - 1; + for (n = 0; dname[0] && left; n += dname[0]) { + count = (dname[0] < (left - 1)) ? dname[0] : (left - 1); + memmove(buf, dname + 1, count); + dname += dname[0] + 1; + left -= count; + buf += count; + if (left) { + left -= 1; + *buf++ = '.'; + } + } + buf[0] = 0; + + return (res); +} + +static int +unpack_data(struct unpack *p, void *data, size_t len) +{ + if (p->err) + return (-1); + + if (p->len - p->offset < len) { + p->err = "too short"; + return (-1); + } + + memmove(data, p->buf + p->offset, len); + p->offset += len; + + return (0); +} + +static int +unpack_u16(struct unpack *p, uint16_t *u16) +{ + if (unpack_data(p, u16, 2) == -1) + return (-1); + + *u16 = ntohs(*u16); + + return (0); +} + +static int +unpack_u32(struct unpack *p, uint32_t *u32) +{ + if (unpack_data(p, u32, 4) == -1) + return (-1); + + *u32 = ntohl(*u32); + + return (0); +} + +static int +unpack_inaddr(struct unpack *p, struct in_addr *a) +{ + return (unpack_data(p, a, 4)); +} + +static int +unpack_in6addr(struct unpack *p, struct in6_addr *a6) +{ + return (unpack_data(p, a6, 16)); +} + +static int +unpack_dname(struct unpack *p, char *dst, size_t max) +{ + ssize_t e; + + if (p->err) + return (-1); + + e = dname_expand(p->buf, p->len, p->offset, &p->offset, dst, max); + if (e == -1) { + p->err = "bad domain name"; + return (-1); + } + if (e < 0 || e > MAXDNAME) { + p->err = "domain name too long"; + return (-1); + } + + return (0); +} diff --git a/usr.sbin/smtpd/unpack_dns.h b/usr.sbin/smtpd/unpack_dns.h new file mode 100644 index 00000000000..2318a0c51e2 --- /dev/null +++ b/usr.sbin/smtpd/unpack_dns.h @@ -0,0 +1,96 @@ +/* $OpenBSD: unpack_dns.h,v 1.1 2018/01/06 07:57:53 sunil Exp $ */ + +/* + * Copyright (c) 2011-2014 Eric Faurot + * + * Permission to use, copy, modify, and distribute this software for any + * purpose with or without fee is hereby granted, provided that the above + * copyright notice and this permission notice appear in all copies. + * + * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES + * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF + * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR + * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES + * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN + * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF + * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. + */ + +#include + +#include + +#include +#include + +struct unpack { + const char *buf; + size_t len; + size_t offset; + const char *err; +}; + +struct dns_header { + uint16_t id; + uint16_t flags; + uint16_t qdcount; + uint16_t ancount; + uint16_t nscount; + uint16_t arcount; +}; + +struct dns_query { + char q_dname[MAXDNAME]; + uint16_t q_type; + uint16_t q_class; +}; + +struct dns_rr { + char rr_dname[MAXDNAME]; + uint16_t rr_type; + uint16_t rr_class; + uint32_t rr_ttl; + union { + struct { + char cname[MAXDNAME]; + } cname; + struct { + uint16_t preference; + char exchange[MAXDNAME]; + } mx; + struct { + char nsname[MAXDNAME]; + } ns; + struct { + char ptrname[MAXDNAME]; + } ptr; + struct { + char mname[MAXDNAME]; + char rname[MAXDNAME]; + uint32_t serial; + uint32_t refresh; + uint32_t retry; + uint32_t expire; + uint32_t minimum; + } soa; + struct { + struct in_addr addr; + } in_a; + struct { + struct in6_addr addr6; + } in_aaaa; + struct { + uint16_t rdlen; + const void *rdata; + } other; + } rr; +}; + +void unpack_init(struct unpack *, const char *, size_t); +int unpack_header(struct unpack *, struct dns_header *); +int unpack_rr(struct unpack *, struct dns_rr *); +int unpack_query(struct unpack *, struct dns_query *); +char *print_dname(const char *, char *, size_t); +ssize_t dname_expand(const unsigned char *, size_t, size_t, size_t *, + char *, size_t); + -- 2.20.1