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![Pedro F. Giffuni](/assets/img/avatar_default.png)
Mainly focus on files that use BSD 2-Clause license, however the tool I was using misidentified many licenses so this was mostly a manual - error prone - task. The Software Package Data Exchange (SPDX) group provides a specification to make it easier for automated tools to detect and summarize well known opensource licenses. We are gradually adopting the specification, noting that the tags are considered only advisory and do not, in any way, superceed or replace the license texts. No functional change intended.
225 lines
4.9 KiB
C
225 lines
4.9 KiB
C
/*-
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* SPDX-License-Identifier: BSD-2-Clause-FreeBSD
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*
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* Copyright (c) 2012-2013 Baptiste Daroussin <bapt@FreeBSD.org>
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* All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer,
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* without modification, immediately at the beginning of the file.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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*
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* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
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* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
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* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
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* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
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* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
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* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
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* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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*/
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#include <sys/cdefs.h>
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__FBSDID("$FreeBSD$");
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#include <stdlib.h>
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#include <string.h>
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#include <netinet/in.h>
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#include <resolv.h>
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#include "dns_utils.h"
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typedef union {
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HEADER hdr;
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unsigned char buf[1024];
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} dns_query;
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static int
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srv_priority_cmp(const void *a, const void *b)
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{
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const struct dns_srvinfo *da, *db;
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unsigned int r, l;
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da = *(struct dns_srvinfo * const *)a;
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db = *(struct dns_srvinfo * const *)b;
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l = da->priority;
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r = db->priority;
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return ((l > r) - (l < r));
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}
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static int
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srv_final_cmp(const void *a, const void *b)
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{
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const struct dns_srvinfo *da, *db;
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unsigned int r, l, wr, wl;
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int res;
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da = *(struct dns_srvinfo * const *)a;
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db = *(struct dns_srvinfo * const *)b;
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l = da->priority;
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r = db->priority;
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res = ((l > r) - (l < r));
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if (res == 0) {
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wl = da->finalweight;
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wr = db->finalweight;
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res = ((wr > wl) - (wr < wl));
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}
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return (res);
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}
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static void
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compute_weight(struct dns_srvinfo **d, int first, int last)
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{
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int i, j, totalweight;
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int *chosen;
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totalweight = 0;
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for (i = 0; i <= last; i++)
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totalweight += d[i]->weight;
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if (totalweight == 0)
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return;
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chosen = malloc(sizeof(int) * (last - first + 1));
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for (i = 0; i <= last; i++) {
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for (;;) {
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chosen[i] = random() % (d[i]->weight * 100 / totalweight);
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for (j = 0; j < i; j++) {
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if (chosen[i] == chosen[j])
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break;
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}
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if (j == i) {
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d[i]->finalweight = chosen[i];
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break;
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}
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}
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}
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free(chosen);
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}
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struct dns_srvinfo *
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dns_getsrvinfo(const char *zone)
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{
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struct dns_srvinfo **res, *first;
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unsigned char *end, *p;
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char host[MAXHOSTNAMELEN];
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dns_query q;
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int len, qdcount, ancount, n, i, f, l;
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unsigned int type, class, ttl, priority, weight, port;
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if ((len = res_query(zone, C_IN, T_SRV, q.buf, sizeof(q.buf))) == -1 ||
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len < (int)sizeof(HEADER))
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return (NULL);
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qdcount = ntohs(q.hdr.qdcount);
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ancount = ntohs(q.hdr.ancount);
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end = q.buf + len;
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p = q.buf + sizeof(HEADER);
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while(qdcount > 0 && p < end) {
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qdcount--;
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if((len = dn_expand(q.buf, end, p, host, MAXHOSTNAMELEN)) < 0)
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return (NULL);
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p += len + NS_QFIXEDSZ;
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}
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res = calloc(ancount, sizeof(struct dns_srvinfo *));
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if (res == NULL)
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return (NULL);
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n = 0;
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while (ancount > 0 && p < end) {
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ancount--;
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len = dn_expand(q.buf, end, p, host, MAXHOSTNAMELEN);
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if (len < 0) {
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for (i = 0; i < n; i++)
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free(res[i]);
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free(res);
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return NULL;
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}
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p += len;
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NS_GET16(type, p);
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NS_GET16(class, p);
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NS_GET32(ttl, p);
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NS_GET16(len, p);
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if (type != T_SRV) {
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p += len;
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continue;
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}
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NS_GET16(priority, p);
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NS_GET16(weight, p);
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NS_GET16(port, p);
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len = dn_expand(q.buf, end, p, host, MAXHOSTNAMELEN);
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if (len < 0) {
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for (i = 0; i < n; i++)
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free(res[i]);
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free(res);
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return (NULL);
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}
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res[n] = malloc(sizeof(struct dns_srvinfo));
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if (res[n] == NULL) {
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for (i = 0; i < n; i++)
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free(res[i]);
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free(res);
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return (NULL);
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}
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res[n]->type = type;
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res[n]->class = class;
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res[n]->ttl = ttl;
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res[n]->priority = priority;
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res[n]->weight = weight;
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res[n]->port = port;
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res[n]->next = NULL;
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strlcpy(res[n]->host, host, MAXHOSTNAMELEN);
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p += len;
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n++;
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}
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qsort(res, n, sizeof(res[0]), srv_priority_cmp);
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priority = f = l = 0;
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for (i = 0; i < n; i++) {
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if (res[i]->priority != priority) {
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if (f != l)
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compute_weight(res, f, l);
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f = i;
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priority = res[i]->priority;
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}
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l = i;
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}
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qsort(res, n, sizeof(res[0]), srv_final_cmp);
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for (i = 0; i < n - 1; i++)
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res[i]->next = res[i + 1];
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first = res[0];
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free(res);
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return (first);
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}
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