1 /* $OpenBSD: carp.c,v 1.11 2015/01/22 17:42:09 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/types.h> 20 #include <sys/socket.h> 21 #include <sys/queue.h> 22 #include <sys/ioctl.h> 23 24 #include <net/if.h> 25 26 #include <errno.h> 27 #include <string.h> 28 #include <stdlib.h> 29 #include <unistd.h> 30 31 #include "relayd.h" 32 33 struct carpgroup { 34 TAILQ_ENTRY(carpgroup) entry; 35 char *group; 36 int do_demote; 37 int changed_by; 38 }; 39 40 TAILQ_HEAD(carpgroups, carpgroup) carpgroups = 41 TAILQ_HEAD_INITIALIZER(carpgroups); 42 43 struct carpgroup *carp_group_find(char *group); 44 int carp_demote_ioctl(char *, int); 45 46 struct carpgroup * 47 carp_group_find(char *group) 48 { 49 struct carpgroup *c; 50 51 TAILQ_FOREACH(c, &carpgroups, entry) 52 if (!strcmp(c->group, group)) 53 return (c); 54 55 return (NULL); 56 } 57 58 int 59 carp_demote_init(char *group, int force) 60 { 61 struct carpgroup *c; 62 int level; 63 64 if ((c = carp_group_find(group)) == NULL) { 65 if ((c = calloc(1, sizeof(struct carpgroup))) == NULL) { 66 log_warn("%s: calloc", __func__); 67 return (-1); 68 } 69 if ((c->group = strdup(group)) == NULL) { 70 log_warn("%s: strdup", __func__); 71 free(c); 72 return (-1); 73 } 74 75 /* only demote if this group already is demoted */ 76 if ((level = carp_demote_get(group)) == -1) { 77 free(c->group); 78 free(c); 79 return (-1); 80 } 81 if (level > 0 || force) 82 c->do_demote = 1; 83 84 TAILQ_INSERT_TAIL(&carpgroups, c, entry); 85 } 86 87 return (0); 88 } 89 90 void 91 carp_demote_shutdown(void) 92 { 93 struct carpgroup *c; 94 95 while ((c = TAILQ_FIRST(&carpgroups)) != NULL) { 96 TAILQ_REMOVE(&carpgroups, c, entry); 97 if (c->do_demote && c->changed_by > 0) 98 carp_demote_ioctl(c->group, -c->changed_by); 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("%s: socket", __func__); 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("%s: invalid group", __func__); 120 return (-1); 121 } 122 123 if (ioctl(s, SIOCGIFGATTR, (caddr_t)&ifgr) == -1) { 124 if (errno == ENOENT) 125 log_warnx("%s: group \"%s\" does not exist", 126 __func__, group); 127 else 128 log_warn("%s: ioctl", __func__); 129 close(s); 130 return (-1); 131 } 132 133 close(s); 134 return ((int)ifgr.ifgr_attrib.ifg_carp_demoted); 135 } 136 137 int 138 carp_demote_set(char *group, int demote) 139 { 140 struct carpgroup *c; 141 142 if ((c = carp_group_find(group)) == NULL) { 143 log_warnx("%s: carp group %s not found", __func__, group); 144 return (-1); 145 } 146 147 if (c->changed_by + demote < 0) { 148 log_warnx("%s: changed_by + demote < 0", __func__); 149 return (-1); 150 } 151 152 if (c->do_demote && carp_demote_ioctl(group, demote) == -1) 153 return (-1); 154 155 c->changed_by += demote; 156 157 /* enable demotion when we return to 0, i. e. all sessions up */ 158 if (demote < 0 && c->changed_by == 0) 159 c->do_demote = 1; 160 161 return (0); 162 } 163 164 int 165 carp_demote_reset(char *group, int value) 166 { 167 int level; 168 int demote = 0; 169 170 if (value < 0) { 171 log_warnx("%s: value < 0", __func__); 172 return (-1); 173 } 174 175 if ((level = carp_demote_get(group)) == -1) 176 return (-1); 177 if (level == value) 178 return (0); 179 180 demote -= level; 181 demote += value; 182 183 if (carp_demote_ioctl(group, demote) == -1) 184 return (-1); 185 186 return (0); 187 } 188 189 int 190 carp_demote_ioctl(char *group, int demote) 191 { 192 int s, res; 193 struct ifgroupreq ifgr; 194 195 if ((s = socket(AF_INET, SOCK_DGRAM, 0)) == -1) { 196 log_warn("%s: socket", __func__); 197 return (-1); 198 } 199 200 bzero(&ifgr, sizeof(ifgr)); 201 if (strlcpy(ifgr.ifgr_name, group, sizeof(ifgr.ifgr_name)) >= 202 sizeof(ifgr.ifgr_name)) { 203 log_warn("%s: invalid group", __func__); 204 return (-1); 205 } 206 ifgr.ifgr_attrib.ifg_carp_demoted = demote; 207 208 if ((res = ioctl(s, SIOCSIFGATTR, (caddr_t)&ifgr)) == -1) 209 log_warn("%s: unable to %s the demote state " 210 "of group '%s'", __func__, 211 (demote > 0) ? "increment" : "decrement", group); 212 else 213 log_info("%s the demote state of group '%s'", 214 (demote > 0) ? "incremented" : "decremented", group); 215 216 close(s); 217 return (res); 218 } 219