1 /* $OpenBSD: carp.c,v 1.5 2007/12/07 17:17:00 reyk 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/param.h> 20 #include <sys/socket.h> 21 #include <sys/ioctl.h> 22 23 #include <net/if.h> 24 25 #include <errno.h> 26 #include <string.h> 27 #include <stdlib.h> 28 #include <unistd.h> 29 #include <event.h> 30 31 #include <openssl/ssl.h> 32 33 #include "relayd.h" 34 35 struct carpgroup { 36 TAILQ_ENTRY(carpgroup) entry; 37 char *group; 38 int do_demote; 39 int changed_by; 40 }; 41 42 TAILQ_HEAD(carpgroups, carpgroup) carpgroups = 43 TAILQ_HEAD_INITIALIZER(carpgroups); 44 45 struct carpgroup *carp_group_find(char *group); 46 int carp_demote_ioctl(char *, int); 47 48 struct carpgroup * 49 carp_group_find(char *group) 50 { 51 struct carpgroup *c; 52 53 TAILQ_FOREACH(c, &carpgroups, entry) 54 if (!strcmp(c->group, group)) 55 return (c); 56 57 return (NULL); 58 } 59 60 int 61 carp_demote_init(char *group, int force) 62 { 63 struct carpgroup *c; 64 int level; 65 66 if ((c = carp_group_find(group)) == NULL) { 67 if ((c = calloc(1, sizeof(struct carpgroup))) == NULL) { 68 log_warn("carp_demote_init calloc"); 69 return (-1); 70 } 71 if ((c->group = strdup(group)) == NULL) { 72 log_warn("carp_demote_init calloc"); 73 free(c); 74 return (-1); 75 } 76 77 /* only demote if this group already is demoted */ 78 if ((level = carp_demote_get(group)) == -1) 79 return (-1); 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 89 void 90 carp_demote_shutdown(void) 91 { 92 struct carpgroup *c; 93 94 while ((c = TAILQ_FIRST(&carpgroups)) != NULL) { 95 TAILQ_REMOVE(&carpgroups, c, entry); 96 for (; c->changed_by > 0; c->changed_by--) 97 if (c->do_demote) 98 carp_demote_ioctl(c->group, -1); 99 100 free(c->group); 101 free(c); 102 } 103 } 104 105 int 106 carp_demote_get(char *group) 107 { 108 int s; 109 struct ifgroupreq ifgr; 110 111 if ((s = socket(AF_INET, SOCK_DGRAM, 0)) == -1) { 112 log_warn("carp_demote_get: socket"); 113 return (-1); 114 } 115 116 bzero(&ifgr, sizeof(ifgr)); 117 if (strlcpy(ifgr.ifgr_name, group, sizeof(ifgr.ifgr_name)) >= 118 sizeof(ifgr.ifgr_name)) { 119 log_warn("carp_demote_get: invalid group"); 120 return (-1); 121 } 122 123 if (ioctl(s, SIOCGIFGATTR, (caddr_t)&ifgr) == -1) { 124 if (errno == ENOENT) 125 log_warnx("group \"%s\" does not exist", group); 126 else 127 log_warn("carp_demote_get: ioctl"); 128 close(s); 129 return (-1); 130 } 131 132 close(s); 133 return ((int)ifgr.ifgr_attrib.ifg_carp_demoted); 134 } 135 136 int 137 carp_demote_set(char *group, int demote) 138 { 139 struct carpgroup *c; 140 141 if ((c = carp_group_find(group)) == NULL) { 142 log_warnx("carp_group_find for %s returned NULL?!", group); 143 return (-1); 144 } 145 146 if (c->changed_by + demote < 0) { 147 log_warnx("carp_demote_set: changed_by + demote < 0"); 148 return (-1); 149 } 150 151 if (c->do_demote && carp_demote_ioctl(group, demote) == -1) 152 return (-1); 153 154 c->changed_by += demote; 155 156 /* enable demotion when we return to 0, i. e. all sessions up */ 157 if (demote < 0 && c->changed_by == 0) 158 c->do_demote = 1; 159 160 return (0); 161 } 162 163 int 164 carp_demote_reset(char *group, int value) 165 { 166 int level; 167 int demote = 0; 168 169 if (value < 0) { 170 log_warnx("carp_demote_reset: value < 0"); 171 return (-1); 172 } 173 174 if ((level = carp_demote_get(group)) == -1) 175 return (-1); 176 if (level == value) 177 return (0); 178 179 demote -= level; 180 demote += value; 181 182 if (carp_demote_ioctl(group, demote) == -1) 183 return (-1); 184 185 return (0); 186 } 187 188 int 189 carp_demote_ioctl(char *group, int demote) 190 { 191 int s, res; 192 struct ifgroupreq ifgr; 193 194 if ((s = socket(AF_INET, SOCK_DGRAM, 0)) == -1) { 195 log_warn("carp_demote_get: socket"); 196 return (-1); 197 } 198 199 bzero(&ifgr, sizeof(ifgr)); 200 if (strlcpy(ifgr.ifgr_name, group, sizeof(ifgr.ifgr_name)) >= 201 sizeof(ifgr.ifgr_name)) { 202 log_warn("carp_demote_ioctl: invalid group"); 203 return (-1); 204 } 205 ifgr.ifgr_attrib.ifg_carp_demoted = demote; 206 207 if ((res = ioctl(s, SIOCSIFGATTR, (caddr_t)&ifgr)) == -1) 208 log_warn("unable to %s the demote state " 209 "of group '%s'", (demote > 0) ? "increment" : "decrement", 210 group); 211 else 212 log_info("%s the demote state of group '%s'", 213 (demote > 0) ? "incremented" : "decremented", group); 214 215 close(s); 216 return (res); 217 } 218