1/* $OpenBSD: carp.c,v 1.3 2009/09/30 12:22:03 claudio Exp $ */ 2 3/* 4 * Copyright (c) 2006 Henning Brauer <henning@openbsd.org> 5 * 6 * Permission to use, copy, modify, and distribute this software for any 7 * purpose with or without fee is hereby granted, provided that the above 8 * copyright notice and this permission notice appear in all copies. 9 * 10 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES 11 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF 12 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR 13 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES 14 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN 15 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF 16 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. 17 */ 18 19#include <sys/types.h> 20#include <sys/socket.h> 21#include <sys/ioctl.h> 22#include <net/if.h> 23 24#include <errno.h> 25#include <string.h> 26#include <stdlib.h> 27#include <unistd.h> 28 29#include "ripd.h" 30#include "log.h" 31 32struct carpgroup { 33 TAILQ_ENTRY(carpgroup) entry; 34 char *group; 35 int do_demote; 36 int changed_by; 37}; 38 39TAILQ_HEAD(carpgroups, carpgroup) carpgroups = 40 TAILQ_HEAD_INITIALIZER(carpgroups); 41 42struct carpgroup *carp_group_find(char *group); 43int carp_demote_ioctl(char *, int); 44 45struct carpgroup * 46carp_group_find(char *group) 47{ 48 struct carpgroup *c; 49 50 TAILQ_FOREACH(c, &carpgroups, entry) 51 if (!strcmp(c->group, group)) 52 return (c); 53 54 return (NULL); 55} 56 57int 58carp_demote_init(char *group, int force) 59{ 60 struct carpgroup *c; 61 int level; 62 63 if ((c = carp_group_find(group)) == NULL) { 64 if ((c = calloc(1, sizeof(struct carpgroup))) == NULL) { 65 log_warn("carp_demote_init calloc"); 66 return (-1); 67 } 68 if ((c->group = strdup(group)) == NULL) { 69 log_warn("carp_demote_init strdup"); 70 free(c); 71 return (-1); 72 } 73 74 /* only demote if this group already is demoted */ 75 if ((level = carp_demote_get(group)) == -1) { 76 free(c->group); 77 free(c); 78 return (-1); 79 } 80 if (level > 0 || force) 81 c->do_demote = 1; 82 83 TAILQ_INSERT_TAIL(&carpgroups, c, entry); 84 } 85 86 return (0); 87} 88 89void 90carp_demote_shutdown(void) 91{ 92 struct carpgroup *c; 93 94 while ((c = TAILQ_FIRST(&carpgroups)) != NULL) { 95 TAILQ_REMOVE(&carpgroups, c, entry); 96 if (c->do_demote && c->changed_by > 0) 97 carp_demote_ioctl(c->group, -c->changed_by); 98 99 free(c->group); 100 free(c); 101 } 102} 103 104int 105carp_demote_get(char *group) 106{ 107 int s; 108 struct ifgroupreq ifgr; 109 110 if ((s = socket(AF_INET, SOCK_DGRAM, 0)) == -1) { 111 log_warn("carp_demote_get: socket"); 112 return (-1); 113 } 114 115 bzero(&ifgr, sizeof(ifgr)); 116 strlcpy(ifgr.ifgr_name, group, sizeof(ifgr.ifgr_name)); 117 118 if (ioctl(s, SIOCGIFGATTR, (caddr_t)&ifgr) == -1) { 119 if (errno == ENOENT) 120 log_warnx("group \"%s\" does not exist", group); 121 else 122 log_warn("carp_demote_get: ioctl"); 123 close(s); 124 return (-1); 125 } 126 127 close(s); 128 return ((int)ifgr.ifgr_attrib.ifg_carp_demoted); 129} 130 131int 132carp_demote_set(char *group, int demote) 133{ 134 struct carpgroup *c; 135 136 if ((c = carp_group_find(group)) == NULL) { 137 log_warnx("carp_group_find for %s returned NULL?!", group); 138 return (-1); 139 } 140 141 if (c->changed_by + demote < 0) { 142 log_warnx("carp_demote_set: changed_by + demote < 0"); 143 return (-1); 144 } 145 146 if (c->do_demote && carp_demote_ioctl(group, demote) == -1) 147 return (-1); 148 149 c->changed_by += demote; 150 151 /* enable demotion when we return to 0, i. e. all sessions up */ 152 if (demote < 0 && c->changed_by == 0) 153 c->do_demote = 1; 154 155 return (0); 156} 157 158int 159carp_demote_ioctl(char *group, int demote) 160{ 161 int s, res; 162 struct ifgroupreq ifgr; 163 164 if ((s = socket(AF_INET, SOCK_DGRAM, 0)) == -1) { 165 log_warn("carp_demote_get: socket"); 166 return (-1); 167 } 168 169 bzero(&ifgr, sizeof(ifgr)); 170 strlcpy(ifgr.ifgr_name, group, sizeof(ifgr.ifgr_name)); 171 ifgr.ifgr_attrib.ifg_carp_demoted = demote; 172 173 if ((res = ioctl(s, SIOCSIFGATTR, (caddr_t)&ifgr)) == -1) 174 log_warn("unable to %s the demote state " 175 "of group '%s'", (demote > 0) ? "increment" : "decrement", 176 group); 177 else 178 log_info("%s the demote state of group '%s'", 179 (demote > 0) ? "incremented" : "decremented", group); 180 181 close(s); 182 return (res); 183} 184