1 /* $OpenBSD: carp.c,v 1.12 2016/08/18 00:45:52 jsg 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 close(s); 121 return (-1); 122 } 123 124 if (ioctl(s, SIOCGIFGATTR, (caddr_t)&ifgr) == -1) { 125 if (errno == ENOENT) 126 log_warnx("%s: group \"%s\" does not exist", 127 __func__, group); 128 else 129 log_warn("%s: ioctl", __func__); 130 close(s); 131 return (-1); 132 } 133 134 close(s); 135 return ((int)ifgr.ifgr_attrib.ifg_carp_demoted); 136 } 137 138 int 139 carp_demote_set(char *group, int demote) 140 { 141 struct carpgroup *c; 142 143 if ((c = carp_group_find(group)) == NULL) { 144 log_warnx("%s: carp group %s not found", __func__, group); 145 return (-1); 146 } 147 148 if (c->changed_by + demote < 0) { 149 log_warnx("%s: changed_by + demote < 0", __func__); 150 return (-1); 151 } 152 153 if (c->do_demote && carp_demote_ioctl(group, demote) == -1) 154 return (-1); 155 156 c->changed_by += demote; 157 158 /* enable demotion when we return to 0, i. e. all sessions up */ 159 if (demote < 0 && c->changed_by == 0) 160 c->do_demote = 1; 161 162 return (0); 163 } 164 165 int 166 carp_demote_reset(char *group, int value) 167 { 168 int level; 169 int demote = 0; 170 171 if (value < 0) { 172 log_warnx("%s: value < 0", __func__); 173 return (-1); 174 } 175 176 if ((level = carp_demote_get(group)) == -1) 177 return (-1); 178 if (level == value) 179 return (0); 180 181 demote -= level; 182 demote += value; 183 184 if (carp_demote_ioctl(group, demote) == -1) 185 return (-1); 186 187 return (0); 188 } 189 190 int 191 carp_demote_ioctl(char *group, int demote) 192 { 193 int s, res; 194 struct ifgroupreq ifgr; 195 196 if ((s = socket(AF_INET, SOCK_DGRAM, 0)) == -1) { 197 log_warn("%s: socket", __func__); 198 return (-1); 199 } 200 201 bzero(&ifgr, sizeof(ifgr)); 202 if (strlcpy(ifgr.ifgr_name, group, sizeof(ifgr.ifgr_name)) >= 203 sizeof(ifgr.ifgr_name)) { 204 log_warn("%s: invalid group", __func__); 205 close(s); 206 return (-1); 207 } 208 ifgr.ifgr_attrib.ifg_carp_demoted = demote; 209 210 if ((res = ioctl(s, SIOCSIFGATTR, (caddr_t)&ifgr)) == -1) 211 log_warn("%s: unable to %s the demote state " 212 "of group '%s'", __func__, 213 (demote > 0) ? "increment" : "decrement", group); 214 else 215 log_info("%s the demote state of group '%s'", 216 (demote > 0) ? "incremented" : "decremented", group); 217 218 close(s); 219 return (res); 220 } 221