/* $NetBSD: ns_newmsg.c,v 1.1.1.2 2012/09/09 16:08:05 christos Exp $ */ /* * Copyright (C) 2009 Internet Systems Consortium, Inc. ("ISC") * * Permission to use, copy, modify, and/or 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 ISC DISCLAIMS ALL WARRANTIES WITH * REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY * AND FITNESS. IN NO EVENT SHALL ISC 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. */ #ifndef lint static const char rcsid[] = "Id: ns_newmsg.c,v 1.3 2009/02/26 10:48:57 marka Exp "; #endif #include #include #include #include static int rdcpy(ns_newmsg *, ns_type, const u_char *, size_t); /* Initialize a "newmsg" object to empty. */ int ns_newmsg_init(u_char *buffer, size_t bufsiz, ns_newmsg *handle) { ns_msg *msg = &handle->msg; memset(handle, 0, sizeof *handle); msg->_msg = buffer; msg->_eom = buffer + bufsiz; msg->_sect = ns_s_qd; msg->_rrnum = 0; msg->_msg_ptr = buffer + NS_HFIXEDSZ; handle->dnptrs[0] = msg->_msg; handle->dnptrs[1] = NULL; handle->lastdnptr = &handle->dnptrs[sizeof handle->dnptrs / sizeof handle->dnptrs[0] - 1]; return (0); } /* Initialize a "newmsg" object by copying an existing parsed message. */ int ns_newmsg_copy(ns_newmsg *handle, ns_msg *msg) { ns_flag flag; ns_sect sect; ns_newmsg_id(handle, ns_msg_id(*msg)); for (flag = ns_f_qr; flag < ns_f_max; flag++) ns_newmsg_flag(handle, flag, ns_msg_getflag(*msg, flag)); for (sect = ns_s_qd; sect < ns_s_max; sect++) { int i, count; count = ns_msg_count(*msg, sect); for (i = 0; i < count; i++) { ns_rr2 rr; int x; if (ns_parserr2(msg, sect, i, &rr) < 0) return (-1); if (sect == ns_s_qd) x = ns_newmsg_q(handle, ns_rr_nname(rr), ns_rr_type(rr), ns_rr_class(rr)); else x = ns_newmsg_rr(handle, sect, ns_rr_nname(rr), ns_rr_type(rr), ns_rr_class(rr), ns_rr_ttl(rr), ns_rr_rdlen(rr), ns_rr_rdata(rr)); if (x < 0) return (-1); } } return (0); } /* Set the message-ID in a "newmsg" object. */ void ns_newmsg_id(ns_newmsg *handle, u_int16_t id) { ns_msg *msg = &handle->msg; msg->_id = id; } /* Set a flag (including rcode or opcode) in a "newmsg" object. */ void ns_newmsg_flag(ns_newmsg *handle, ns_flag flag, u_int value) { extern struct _ns_flagdata _ns_flagdata[16]; struct _ns_flagdata *fd = &_ns_flagdata[flag]; ns_msg *msg = &handle->msg; assert(flag < ns_f_max); msg->_flags &= (~fd->mask); msg->_flags |= (value << fd->shift); } /* Add a question (or zone, if it's an update) to a "newmsg" object. */ int ns_newmsg_q(ns_newmsg *handle, ns_nname_ct qname, ns_type qtype, ns_class qclass) { ns_msg *msg = &handle->msg; u_char *t; int n; if (msg->_sect != ns_s_qd) { errno = ENODEV; return (-1); } t = (u_char *) (unsigned long) msg->_msg_ptr; if (msg->_rrnum == 0) msg->_sections[ns_s_qd] = t; n = ns_name_pack(qname, t, msg->_eom - t, handle->dnptrs, handle->lastdnptr); if (n < 0) return (-1); t += n; if (t + QFIXEDSZ >= msg->_eom) { errno = EMSGSIZE; return (-1); } NS_PUT16(qtype, t); NS_PUT16(qclass, t); msg->_msg_ptr = t; msg->_counts[ns_s_qd] = ++msg->_rrnum; return (0); } /* Add an RR to a "newmsg" object. */ int ns_newmsg_rr(ns_newmsg *handle, ns_sect sect, ns_nname_ct name, ns_type type, ns_class rr_class, u_int32_t ttl, u_int16_t rdlen, const u_char *rdata) { ns_msg *msg = &handle->msg; u_char *t; int n; if (sect < msg->_sect) { errno = ENODEV; return (-1); } t = (u_char *) (unsigned long) msg->_msg_ptr; if (sect > msg->_sect) { msg->_sect = sect; msg->_sections[sect] = t; msg->_rrnum = 0; } n = ns_name_pack(name, t, msg->_eom - t, handle->dnptrs, handle->lastdnptr); if (n < 0) return (-1); t += n; if (t + RRFIXEDSZ + rdlen >= msg->_eom) { errno = EMSGSIZE; return (-1); } NS_PUT16(type, t); NS_PUT16(rr_class, t); NS_PUT32(ttl, t); msg->_msg_ptr = t; if (rdcpy(handle, type, rdata, rdlen) < 0) return (-1); msg->_counts[sect] = ++msg->_rrnum; return (0); } /* Complete a "newmsg" object and return its size for use in write(). * (Note: the "newmsg" object is also made ready for ns_parserr() etc.) */ size_t ns_newmsg_done(ns_newmsg *handle) { ns_msg *msg = &handle->msg; ns_sect sect; u_char *t; t = (u_char *) (unsigned long) msg->_msg; NS_PUT16(msg->_id, t); NS_PUT16(msg->_flags, t); for (sect = 0; sect < ns_s_max; sect++) NS_PUT16(msg->_counts[sect], t); msg->_eom = msg->_msg_ptr; msg->_sect = ns_s_max; msg->_rrnum = -1; msg->_msg_ptr = NULL; return (msg->_eom - msg->_msg); } /* Private. */ /* Copy an RDATA, using compression pointers where RFC1035 permits. */ static int rdcpy(ns_newmsg *handle, ns_type type, const u_char *rdata, size_t rdlen) { ns_msg *msg = &handle->msg; u_char *p = (u_char *) (unsigned long) msg->_msg_ptr; u_char *t = p + NS_INT16SZ; u_char *s = t; int n; switch (type) { case ns_t_soa: /* MNAME. */ n = ns_name_pack(rdata, t, msg->_eom - t, handle->dnptrs, handle->lastdnptr); if (n < 0) return (-1); t += n; if (ns_name_skip(&rdata, msg->_eom) < 0) return (-1); /* ANAME. */ n = ns_name_pack(rdata, t, msg->_eom - t, handle->dnptrs, handle->lastdnptr); if (n < 0) return (-1); t += n; if (ns_name_skip(&rdata, msg->_eom) < 0) return (-1); /* Serial, Refresh, Retry, Expiry, and Minimum. */ if ((msg->_eom - t) < (NS_INT32SZ * 5)) { errno = EMSGSIZE; return (-1); } memcpy(t, rdata, NS_INT32SZ * 5); t += (NS_INT32SZ * 5); break; case ns_t_ptr: case ns_t_cname: case ns_t_ns: /* PTRDNAME, CNAME, or NSDNAME. */ n = ns_name_pack(rdata, t, msg->_eom - t, handle->dnptrs, handle->lastdnptr); if (n < 0) return (-1); t += n; break; default: memcpy(t, rdata, rdlen); t += rdlen; } NS_PUT16(t - s, p); msg->_msg_ptr = t; return (0); }