thodg/acme-client/dnsproc.c

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• Hash : a133bbdf
  Author : Thomas de Grivel
  Date : 2025-09-13T23:16:24
  

  ported to FreeBSD
  

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• dnsproc.c

• /*	$Id: dnsproc.c,v 1.12 2021/12/13 13:30:39 jca Exp $ */
  /*
   * Copyright (c) 2016 Kristaps Dzonsons <kristaps@bsd.lv>
   *
   * 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 AUTHORS DISCLAIM ALL WARRANTIES
   * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
   * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHORS 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 <sys/socket.h>
  #include <arpa/inet.h>
  
  #include <err.h>
  #include <netdb.h>
  #include <stdio.h>
  #include <stdlib.h>
  #include <string.h>
  #include <unistd.h>
  #ifdef __FreeBSD__
  # include <netinet/in.h>
  #endif
  
  #include "extern.h"
  
  struct	addr {
  	int	 family; /* 4 for PF_INET, 6 for PF_INET6 */
  	char	 ip[INET6_ADDRSTRLEN];
  };
  
  /*
   * This is a modified version of host_dns in config.c of OpenBSD's ntpd.
   */
  /*
   * Copyright (c) 2003, 2004 Henning Brauer <henning@openbsd.org>
   *
   * 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.
   */
  static ssize_t
  host_dns(const char *s, struct addr *vec)
  {
  	struct addrinfo		 hints, *res0, *res;
  	int			 error;
  	ssize_t			 vecsz;
  	struct sockaddr		*sa;
  
  	memset(&hints, 0, sizeof(hints));
  	hints.ai_family = PF_UNSPEC;
  	hints.ai_socktype = SOCK_DGRAM; /* DUMMY */
  	hints.ai_flags = AI_ADDRCONFIG;
  
  	error = getaddrinfo(s, NULL, &hints, &res0);
  
  	if (error == EAI_AGAIN ||
  		/* FIXME */
  #if defined(EAI_NODATA)
  	    error == EAI_NODATA ||
  #endif
  	    error == EAI_NONAME)
  		return 0;
  
  	if (error) {
  		warnx("%s: parse error: %s",
  		    s, gai_strerror(error));
  		return -1;
  	}
  
  	for (vecsz = 0, res = res0;
  	    res != NULL && vecsz < MAX_SERVERS_DNS;
  	    res = res->ai_next) {
  		if (res->ai_family != AF_INET &&
  		    res->ai_family != AF_INET6)
  			continue;
  
  		sa = res->ai_addr;
  
  		if (res->ai_family == AF_INET) {
  			vec[vecsz].family = 4;
  			inet_ntop(AF_INET,
  			    &(((struct sockaddr_in *)sa)->sin_addr),
  				vec[vecsz].ip, INET6_ADDRSTRLEN);
  		} else {
  			vec[vecsz].family = 6;
  			inet_ntop(AF_INET6,
  			    &(((struct sockaddr_in6 *)sa)->sin6_addr),
  			    vec[vecsz].ip, INET6_ADDRSTRLEN);
  		}
  
  		dodbg("%s: DNS: %s", s, vec[vecsz].ip);
  		vecsz++;
  	}
  
  	freeaddrinfo(res0);
  	return vecsz;
  }
  
  int
  dnsproc(int nfd)
  {
  	char		*look = NULL, *last = NULL;
  	struct addr	 v[MAX_SERVERS_DNS];
  	int		 rc = 0, cc;
  	long		 lval;
  	ssize_t		 vsz = 0;
  	size_t		 i;
  	enum dnsop	 op;
  
  #if defined(__OpenBSD__)
  	if (pledge("stdio dns", NULL) == -1) {
  		warn("pledge");
  		goto out;
  	}
  #endif
  	/*
  	 * This is simple: just loop on a request operation, and each
  	 * time we write back zero or more entries.
  	 * Also do a simple trick and cache the last lookup.
  	 */
  
  	for (;;) {
  		op = DNS__MAX;
  		if ((lval = readop(nfd, COMM_DNS)) == 0)
  			op = DNS_STOP;
  		else if (lval == DNS_LOOKUP)
  			op = lval;
  
  		if (op == DNS__MAX) {
  			warnx("unknown operation from netproc");
  			goto out;
  		} else if (op == DNS_STOP)
  			break;
  
  		if ((look = readstr(nfd, COMM_DNSQ)) == NULL)
  			goto out;
  
  		/*
  		 * Check if we're asked to repeat the lookup.
  		 * If not, request it from host_dns().
  		 */
  
  		if (last == NULL || strcmp(look, last)) {
  			if ((vsz = host_dns(look, v)) < 0)
  				goto out;
  
  			free(last);
  			last = look;
  			look = NULL;
  		} else {
  			free(look);
  			look = NULL;
  		}
  
  		if ((cc = writeop(nfd, COMM_DNSLEN, vsz)) == 0)
  			break;
  		else if (cc < 0)
  			goto out;
  		for (i = 0; i < (size_t)vsz; i++) {
  			if (writeop(nfd, COMM_DNSF, v[i].family) <= 0)
  				goto out;
  			if (writestr(nfd, COMM_DNSA, v[i].ip) <= 0)
  				goto out;
  		}
  	}
  
  	rc = 1;
  out:
  	close(nfd);
  	free(look);
  	free(last);
  	return rc;
  }
  

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