1 6b5c4000 2026-03-02 rsadowski /*	$OpenBSD: carp.c,v 1.14 2026/03/02 19:28:01 rsadowski Exp $ */
  2 30640247 2007-02-22 reyk 
  3 30640247 2007-02-22 reyk /*
  4 30640247 2007-02-22 reyk  * Copyright (c) 2006 Henning Brauer <henning@openbsd.org>
  5 30640247 2007-02-22 reyk  *
  6 30640247 2007-02-22 reyk  * Permission to use, copy, modify, and distribute this software for any
  7 30640247 2007-02-22 reyk  * purpose with or without fee is hereby granted, provided that the above
  8 30640247 2007-02-22 reyk  * copyright notice and this permission notice appear in all copies.
  9 30640247 2007-02-22 reyk  *
 10 30640247 2007-02-22 reyk  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 11 30640247 2007-02-22 reyk  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 12 30640247 2007-02-22 reyk  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 13 30640247 2007-02-22 reyk  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 14 30640247 2007-02-22 reyk  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 15 30640247 2007-02-22 reyk  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 16 30640247 2007-02-22 reyk  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 17 30640247 2007-02-22 reyk  */
 18 30640247 2007-02-22 reyk 
 19 d93c36af 2015-01-22 reyk #include <sys/types.h>
 20 30640247 2007-02-22 reyk #include <sys/socket.h>
 21 d93c36af 2015-01-22 reyk #include <sys/queue.h>
 22 30640247 2007-02-22 reyk #include <sys/ioctl.h>
 23 e1f9d231 2007-11-24 reyk 
 24 30640247 2007-02-22 reyk #include <net/if.h>
 25 30640247 2007-02-22 reyk 
 26 30640247 2007-02-22 reyk #include <errno.h>
 27 30640247 2007-02-22 reyk #include <string.h>
 28 30640247 2007-02-22 reyk #include <stdlib.h>
 29 30640247 2007-02-22 reyk #include <unistd.h>
 30 30640247 2007-02-22 reyk 
 31 6d0767ae 2007-12-07 reyk #include "relayd.h"
 32 6b5c4000 2026-03-02 rsadowski #include "log.h"
 33 30640247 2007-02-22 reyk 
 34 30640247 2007-02-22 reyk struct carpgroup {
 35 30640247 2007-02-22 reyk 	TAILQ_ENTRY(carpgroup)	 entry;
 36 30640247 2007-02-22 reyk 	char			*group;
 37 30640247 2007-02-22 reyk 	int			 do_demote;
 38 30640247 2007-02-22 reyk 	int			 changed_by;
 39 30640247 2007-02-22 reyk };
 40 30640247 2007-02-22 reyk 
 41 30640247 2007-02-22 reyk TAILQ_HEAD(carpgroups, carpgroup)	carpgroups =
 42 30640247 2007-02-22 reyk     TAILQ_HEAD_INITIALIZER(carpgroups);
 43 30640247 2007-02-22 reyk 
 44 30640247 2007-02-22 reyk struct carpgroup	*carp_group_find(char *group);
 45 30640247 2007-02-22 reyk int			 carp_demote_ioctl(char *, int);
 46 30640247 2007-02-22 reyk 
 47 30640247 2007-02-22 reyk struct carpgroup *
 48 30640247 2007-02-22 reyk carp_group_find(char *group)
 49 30640247 2007-02-22 reyk {
 50 30640247 2007-02-22 reyk 	struct carpgroup	*c;
 51 30640247 2007-02-22 reyk 
 52 30640247 2007-02-22 reyk 	TAILQ_FOREACH(c, &carpgroups, entry)
 53 30640247 2007-02-22 reyk 		if (!strcmp(c->group, group))
 54 30640247 2007-02-22 reyk 			return (c);
 55 30640247 2007-02-22 reyk 
 56 30640247 2007-02-22 reyk 	return (NULL);
 57 30640247 2007-02-22 reyk }
 58 30640247 2007-02-22 reyk 
 59 30640247 2007-02-22 reyk int
 60 30640247 2007-02-22 reyk carp_demote_init(char *group, int force)
 61 30640247 2007-02-22 reyk {
 62 30640247 2007-02-22 reyk 	struct carpgroup	*c;
 63 30640247 2007-02-22 reyk 	int			 level;
 64 30640247 2007-02-22 reyk 
 65 80854f02 2026-01-01 rsadowski 	if (carp_group_find(group) != NULL)
 66 80854f02 2026-01-01 rsadowski 		return (0);
 67 3e2ddb06 2007-02-22 reyk 
 68 80854f02 2026-01-01 rsadowski 	if ((c = calloc(1, sizeof(struct carpgroup))) == NULL) {
 69 80854f02 2026-01-01 rsadowski 		log_warn("%s: calloc", __func__);
 70 80854f02 2026-01-01 rsadowski 		return (-1);
 71 30640247 2007-02-22 reyk 	}
 72 80854f02 2026-01-01 rsadowski 	if ((c->group = strdup(group)) == NULL) {
 73 80854f02 2026-01-01 rsadowski 		log_warn("%s: strdup", __func__);
 74 80854f02 2026-01-01 rsadowski 		free(c);
 75 80854f02 2026-01-01 rsadowski 		return (-1);
 76 80854f02 2026-01-01 rsadowski 	}
 77 80854f02 2026-01-01 rsadowski 	/* only demote if this group already is demoted */
 78 80854f02 2026-01-01 rsadowski 	if ((level = carp_demote_get(group)) == -1) {
 79 80854f02 2026-01-01 rsadowski 		free(c->group);
 80 80854f02 2026-01-01 rsadowski 		free(c);
 81 80854f02 2026-01-01 rsadowski 		return (-1);
 82 80854f02 2026-01-01 rsadowski 	}
 83 80854f02 2026-01-01 rsadowski 	if (level > 0 || force)
 84 80854f02 2026-01-01 rsadowski 		c->do_demote = 1;
 85 30640247 2007-02-22 reyk 
 86 80854f02 2026-01-01 rsadowski 	TAILQ_INSERT_TAIL(&carpgroups, c, entry);
 87 30640247 2007-02-22 reyk 	return (0);
 88 30640247 2007-02-22 reyk }
 89 30640247 2007-02-22 reyk 
 90 30640247 2007-02-22 reyk void
 91 30640247 2007-02-22 reyk carp_demote_shutdown(void)
 92 30640247 2007-02-22 reyk {
 93 30640247 2007-02-22 reyk 	struct carpgroup	*c;
 94 30640247 2007-02-22 reyk 
 95 30640247 2007-02-22 reyk 	while ((c = TAILQ_FIRST(&carpgroups)) != NULL) {
 96 30640247 2007-02-22 reyk 		TAILQ_REMOVE(&carpgroups, c, entry);
 97 f6e42d8e 2009-09-30 claudio 		if (c->do_demote && c->changed_by > 0)
 98 f6e42d8e 2009-09-30 claudio 			carp_demote_ioctl(c->group, -c->changed_by);
 99 30640247 2007-02-22 reyk 
100 30640247 2007-02-22 reyk 		free(c->group);
101 30640247 2007-02-22 reyk 		free(c);
102 30640247 2007-02-22 reyk 	}
103 30640247 2007-02-22 reyk }
104 30640247 2007-02-22 reyk 
105 30640247 2007-02-22 reyk int
106 30640247 2007-02-22 reyk carp_demote_get(char *group)
107 30640247 2007-02-22 reyk {
108 30640247 2007-02-22 reyk 	int			s;
109 30640247 2007-02-22 reyk 	struct ifgroupreq	ifgr;
110 30640247 2007-02-22 reyk 
111 30640247 2007-02-22 reyk 	if ((s = socket(AF_INET, SOCK_DGRAM, 0)) == -1) {
112 666bd316 2011-05-05 reyk 		log_warn("%s: socket", __func__);
113 30640247 2007-02-22 reyk 		return (-1);
114 30640247 2007-02-22 reyk 	}
115 30640247 2007-02-22 reyk 
116 30640247 2007-02-22 reyk 	bzero(&ifgr, sizeof(ifgr));
117 1193f29c 2007-02-26 reyk 	if (strlcpy(ifgr.ifgr_name, group, sizeof(ifgr.ifgr_name)) >=
118 1193f29c 2007-02-26 reyk 	    sizeof(ifgr.ifgr_name)) {
119 666bd316 2011-05-05 reyk 		log_warn("%s: invalid group", __func__);
120 cefecd95 2016-08-18 jsg 		close(s);
121 1193f29c 2007-02-26 reyk 		return (-1);
122 1193f29c 2007-02-26 reyk 	}
123 30640247 2007-02-22 reyk 
124 30640247 2007-02-22 reyk 	if (ioctl(s, SIOCGIFGATTR, (caddr_t)&ifgr) == -1) {
125 30640247 2007-02-22 reyk 		if (errno == ENOENT)
126 666bd316 2011-05-05 reyk 			log_warnx("%s: group \"%s\" does not exist",
127 666bd316 2011-05-05 reyk 			    __func__, group);
128 30640247 2007-02-22 reyk 		else
129 666bd316 2011-05-05 reyk 			log_warn("%s: ioctl", __func__);
130 30640247 2007-02-22 reyk 		close(s);
131 30640247 2007-02-22 reyk 		return (-1);
132 30640247 2007-02-22 reyk 	}
133 30640247 2007-02-22 reyk 
134 30640247 2007-02-22 reyk 	close(s);
135 30640247 2007-02-22 reyk 	return ((int)ifgr.ifgr_attrib.ifg_carp_demoted);
136 30640247 2007-02-22 reyk }
137 30640247 2007-02-22 reyk 
138 30640247 2007-02-22 reyk int
139 30640247 2007-02-22 reyk carp_demote_set(char *group, int demote)
140 30640247 2007-02-22 reyk {
141 30640247 2007-02-22 reyk 	struct carpgroup	*c;
142 30640247 2007-02-22 reyk 
143 30640247 2007-02-22 reyk 	if ((c = carp_group_find(group)) == NULL) {
144 666bd316 2011-05-05 reyk 		log_warnx("%s: carp group %s not found", __func__, group);
145 30640247 2007-02-22 reyk 		return (-1);
146 30640247 2007-02-22 reyk 	}
147 30640247 2007-02-22 reyk 
148 30640247 2007-02-22 reyk 	if (c->changed_by + demote < 0) {
149 666bd316 2011-05-05 reyk 		log_warnx("%s: changed_by + demote < 0", __func__);
150 30640247 2007-02-22 reyk 		return (-1);
151 30640247 2007-02-22 reyk 	}
152 30640247 2007-02-22 reyk 
153 30640247 2007-02-22 reyk 	if (c->do_demote && carp_demote_ioctl(group, demote) == -1)
154 30640247 2007-02-22 reyk 		return (-1);
155 30640247 2007-02-22 reyk 
156 30640247 2007-02-22 reyk 	c->changed_by += demote;
157 30640247 2007-02-22 reyk 
158 30640247 2007-02-22 reyk 	/* enable demotion when we return to 0, i. e. all sessions up */
159 30640247 2007-02-22 reyk 	if (demote < 0 && c->changed_by == 0)
160 30640247 2007-02-22 reyk 		c->do_demote = 1;
161 30640247 2007-02-22 reyk 
162 30640247 2007-02-22 reyk 	return (0);
163 30640247 2007-02-22 reyk }
164 30640247 2007-02-22 reyk 
165 30640247 2007-02-22 reyk int
166 30640247 2007-02-22 reyk carp_demote_reset(char *group, int value)
167 30640247 2007-02-22 reyk {
168 30640247 2007-02-22 reyk 	int			 level;
169 30640247 2007-02-22 reyk 	int			 demote = 0;
170 30640247 2007-02-22 reyk 
171 30640247 2007-02-22 reyk 	if (value < 0) {
172 666bd316 2011-05-05 reyk 		log_warnx("%s: value < 0", __func__);
173 30640247 2007-02-22 reyk 		return (-1);
174 30640247 2007-02-22 reyk 	}
175 30640247 2007-02-22 reyk 
176 30640247 2007-02-22 reyk 	if ((level = carp_demote_get(group)) == -1)
177 30640247 2007-02-22 reyk 		return (-1);
178 30640247 2007-02-22 reyk 	if (level == value)
179 30640247 2007-02-22 reyk 		return (0);
180 30640247 2007-02-22 reyk 
181 30640247 2007-02-22 reyk 	demote -= level;
182 30640247 2007-02-22 reyk 	demote += value;
183 30640247 2007-02-22 reyk 
184 30640247 2007-02-22 reyk 	if (carp_demote_ioctl(group, demote) == -1)
185 30640247 2007-02-22 reyk 		return (-1);
186 30640247 2007-02-22 reyk 
187 30640247 2007-02-22 reyk 	return (0);
188 30640247 2007-02-22 reyk }
189 30640247 2007-02-22 reyk 
190 30640247 2007-02-22 reyk int
191 30640247 2007-02-22 reyk carp_demote_ioctl(char *group, int demote)
192 30640247 2007-02-22 reyk {
193 30640247 2007-02-22 reyk 	int			s, res;
194 30640247 2007-02-22 reyk 	struct ifgroupreq	ifgr;
195 30640247 2007-02-22 reyk 
196 30640247 2007-02-22 reyk 	if ((s = socket(AF_INET, SOCK_DGRAM, 0)) == -1) {
197 666bd316 2011-05-05 reyk 		log_warn("%s: socket", __func__);
198 30640247 2007-02-22 reyk 		return (-1);
199 30640247 2007-02-22 reyk 	}
200 30640247 2007-02-22 reyk 
201 30640247 2007-02-22 reyk 	bzero(&ifgr, sizeof(ifgr));
202 1193f29c 2007-02-26 reyk 	if (strlcpy(ifgr.ifgr_name, group, sizeof(ifgr.ifgr_name)) >=
203 1193f29c 2007-02-26 reyk 	    sizeof(ifgr.ifgr_name)) {
204 666bd316 2011-05-05 reyk 		log_warn("%s: invalid group", __func__);
205 cefecd95 2016-08-18 jsg 		close(s);
206 1193f29c 2007-02-26 reyk 		return (-1);
207 1193f29c 2007-02-26 reyk 	}
208 30640247 2007-02-22 reyk 	ifgr.ifgr_attrib.ifg_carp_demoted = demote;
209 30640247 2007-02-22 reyk 
210 30640247 2007-02-22 reyk 	if ((res = ioctl(s, SIOCSIFGATTR, (caddr_t)&ifgr)) == -1)
211 666bd316 2011-05-05 reyk 		log_warn("%s: unable to %s the demote state "
212 666bd316 2011-05-05 reyk 		    "of group '%s'", __func__,
213 666bd316 2011-05-05 reyk 		    (demote > 0) ? "increment" : "decrement", group);
214 30640247 2007-02-22 reyk 	else
215 30640247 2007-02-22 reyk 		log_info("%s the demote state of group '%s'",
216 30640247 2007-02-22 reyk 		    (demote > 0) ? "incremented" : "decremented", group);
217 30640247 2007-02-22 reyk 
218 3e2ddb06 2007-02-22 reyk 	close(s);
219 30640247 2007-02-22 reyk 	return (res);
220 30640247 2007-02-22 reyk }