X-Git-Url: https://code.citadel.org/?a=blobdiff_plain;f=citadel%2Fdomain.c;h=3c4f1455c375d03693a93b349db36b4bb32c9ec3;hb=ea55c1f82ea74c3837ad694c238f40744044aed7;hp=f64458ed408f303b6a42486475bff619cba072b6;hpb=cc6b14b4fcf02e58135c04d5b8c0ae95b121b44e;p=citadel.git diff --git a/citadel/domain.c b/citadel/domain.c index f64458ed4..3c4f1455c 100644 --- a/citadel/domain.c +++ b/citadel/domain.c @@ -1,35 +1,46 @@ /* - * $Id$ - * * DNS lookup for SMTP sender * + * Copyright (c) 1987-2021 by the citadel.org team + * + * This program is open source software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License, version 3. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. */ -#include -#include -#include -#include +#include "sysdep.h" #include +#include +#ifdef HAVE_RESOLV_H #include +#ifdef HAVE_ARPA_NAMESER_COMPAT_H +#include +#endif #include +#endif +#include #include "sysdep_decls.h" #include "citadel.h" #include "domain.h" -#include "server.h" -#include "tools.h" #include "internet_addressing.h" /* - * get_smarthosts() checks the Internet configuration for "smarthost" + * get_hosts() checks the Internet configuration for various types of * entries and returns them in the same format as getmx() does -- fill the * buffer with a delimited list of hosts and return the number of hosts. + * + * This is used to fetch MX smarthosts, SpamAssassin hosts, etc. */ -int get_smarthosts(char *mxbuf) { +int get_hosts(char *mxbuf, char *rectype) { int config_lines; int i; - char buf[SIZ]; - char host[SIZ], type[SIZ]; + char buf[256]; + char host[256], type[256]; int total_smarthosts = 0; if (inetcfg == NULL) return(0); @@ -37,11 +48,11 @@ int get_smarthosts(char *mxbuf) { config_lines = num_tokens(inetcfg, '\n'); for (i=0; ipref; + pref2 = ((const struct mx *)mx2)->pref; + if (pref1 > pref2) { return(1); } else if (pref1 < pref2) { - return(1); + return(0); } else { return(rand() % 2); @@ -70,33 +87,6 @@ inline int mx_compare_pref(int pref1, int pref2) { } -/* - * sort_mxrecs() - * - * Sort a pile of MX records (struct mx, definted in domain.h) by preference - * - */ -void sort_mxrecs(struct mx *mxrecs, int num_mxrecs) { - int a, b; - struct mx hold1, hold2; - - if (num_mxrecs < 2) return; - - /* do the sort */ - for (a = num_mxrecs - 2; a >= 0; --a) { - for (b = 0; b <= a; ++b) { - if (mx_compare_pref(mxrecs[b].pref,mxrecs[b+1].pref)) { - memcpy(&hold1, &mxrecs[b], sizeof(struct mx)); - memcpy(&hold2, &mxrecs[b+1], sizeof(struct mx)); - memcpy(&mxrecs[b], &hold2, sizeof(struct mx)); - memcpy(&mxrecs[b+1], &hold1, sizeof(struct mx)); - } - } - } -} - - - /* * getmx() * @@ -108,10 +98,14 @@ void sort_mxrecs(struct mx *mxrecs, int num_mxrecs) { * */ int getmx(char *mxbuf, char *dest) { + +#ifdef HAVE_RESOLV_H union { u_char bytes[1024]; HEADER header; } answer; +#endif + int ret; unsigned char *startptr, *endptr, *ptr; char expanded_buf[1024]; @@ -121,51 +115,48 @@ int getmx(char *mxbuf, char *dest) { struct mx *mxrecs = NULL; int num_mxrecs = 0; - + /* If we're configured to send all mail to a smart-host, then our * job here is really easy. */ - n = get_smarthosts(mxbuf); - if (n > 0) return(n); + n = get_hosts(mxbuf, "smarthost"); + if (n > 0) { + return(n); + } /* * No smart-host? Look up the best MX for a site. + * Make a call to the resolver library. */ - ret = res_query( - dest, - C_IN, T_MX, (unsigned char *)answer.bytes, sizeof(answer) ); + + ret = res_query(dest, C_IN, T_MX, (unsigned char *)answer.bytes, sizeof(answer)); if (ret < 0) { - mxrecs = mallok(sizeof(struct mx)); + mxrecs = malloc(sizeof(struct mx)); mxrecs[0].pref = 0; strcpy(mxrecs[0].host, dest); num_mxrecs = 1; } else { - /* If we had to truncate, shrink the number to avoid fireworks */ - if (ret > sizeof(answer)) + if (ret > sizeof(answer)) { ret = sizeof(answer); + } - startptr = &answer.bytes[0]; /* start and end of buffer */ + startptr = &answer.bytes[0]; // start and end of buffer endptr = &answer.bytes[ret]; - ptr = startptr + HFIXEDSZ; /* advance past header */ + ptr = startptr + HFIXEDSZ; // advance past header for (qdcount = ntohs(answer.header.qdcount); qdcount--; ptr += ret + QFIXEDSZ) { if ((ret = dn_skipname(ptr, endptr)) < 0) { - lprintf(9, "dn_skipname error\n"); + syslog(LOG_DEBUG, "domain: dn_skipname error"); return(0); } } while(1) { memset(expanded_buf, 0, sizeof(expanded_buf)); - ret = dn_expand(startptr, - endptr, - ptr, - expanded_buf, - sizeof(expanded_buf) - ); + ret = dn_expand(startptr, endptr, ptr, expanded_buf, sizeof(expanded_buf)); if (ret < 0) break; ptr += ret; @@ -179,37 +170,42 @@ int getmx(char *mxbuf, char *dest) { else { GETSHORT(pref, ptr); - ret = dn_expand(startptr, - endptr, - ptr, - expanded_buf, - sizeof(expanded_buf) - ); + ret = dn_expand(startptr, endptr, ptr, expanded_buf, sizeof(expanded_buf)); ptr += ret; - ++num_mxrecs; - if (mxrecs == NULL) { - mxrecs = mallok(sizeof(struct mx)); - } - else { - mxrecs = reallok(mxrecs, - (sizeof(struct mx) * num_mxrecs) ); - } + // If there are no MX records for the domain, resolv will give us a single one with zero length. + // Make sure we only record actual MX records and not the blank. + if (strlen(expanded_buf) > 0) { + ++num_mxrecs; + if (mxrecs == NULL) { + mxrecs = malloc(sizeof(struct mx)); + } + else { + mxrecs = realloc(mxrecs, (sizeof(struct mx) * num_mxrecs) ); + } - mxrecs[num_mxrecs - 1].pref = pref; - strcpy(mxrecs[num_mxrecs - 1].host, - expanded_buf); + mxrecs[num_mxrecs - 1].pref = pref; + strcpy(mxrecs[num_mxrecs - 1].host, expanded_buf); + } } } } - sort_mxrecs(mxrecs, num_mxrecs); + /* Sort the MX records by preference */ + if (num_mxrecs > 1) { + qsort(mxrecs, num_mxrecs, sizeof(struct mx), mx_compare_pref); + } strcpy(mxbuf, ""); for (n=0; n