Annotation of embedaddon/dnsmasq/src/ipset.c, revision 1.1

1.1     ! misho       1: /* ipset.c is Copyright (c) 2013 Jason A. Donenfeld <Jason@zx2c4.com>. All Rights Reserved.
        !             2: 
        !             3:    This program is free software; you can redistribute it and/or modify
        !             4:    it under the terms of the GNU General Public License as published by
        !             5:    the Free Software Foundation; version 2 dated June, 1991, or
        !             6:    (at your option) version 3 dated 29 June, 2007.
        !             7:  
        !             8:    This program is distributed in the hope that it will be useful,
        !             9:    but WITHOUT ANY WARRANTY; without even the implied warranty of
        !            10:    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
        !            11:    GNU General Public License for more details.
        !            12:      
        !            13:    You should have received a copy of the GNU General Public License
        !            14:    along with this program.  If not, see <http://www.gnu.org/licenses/>.
        !            15: */
        !            16: 
        !            17: #include "dnsmasq.h"
        !            18: 
        !            19: #ifdef HAVE_IPSET
        !            20: 
        !            21: #include <string.h>
        !            22: #include <errno.h>
        !            23: #include <sys/types.h>
        !            24: #include <sys/socket.h>
        !            25: #include <sys/utsname.h>
        !            26: #include <arpa/inet.h>
        !            27: #include <linux/version.h>
        !            28: #include <linux/netlink.h>
        !            29: #include <linux/netfilter/nfnetlink.h>
        !            30: #ifndef NFNL_SUBSYS_IPSET
        !            31: #define NFNL_SUBSYS_IPSET 6
        !            32: #define IPSET_ATTR_DATA 7
        !            33: #define IPSET_ATTR_IP 1
        !            34: #define IPSET_ATTR_IPADDR_IPV4 1
        !            35: #define IPSET_ATTR_IPADDR_IPV6 2
        !            36: #define IPSET_ATTR_PROTOCOL 1
        !            37: #define IPSET_ATTR_SETNAME 2
        !            38: #define IPSET_CMD_ADD 9
        !            39: #define IPSET_CMD_DEL 10
        !            40: #define IPSET_MAXNAMELEN 32
        !            41: #define IPSET_PROTOCOL 6
        !            42: #else
        !            43: #include <linux/netfilter/ipset/ip_set.h>
        !            44: #endif
        !            45: 
        !            46: /* data structure size in here is fixed */
        !            47: #define BUFF_SZ 256
        !            48: 
        !            49: #define NL_ALIGN(len) (((len)+3) & ~(3))
        !            50: static const struct sockaddr_nl snl = { .nl_family = AF_NETLINK };
        !            51: static int ipset_sock, old_kernel;
        !            52: static char *buffer;
        !            53: 
        !            54: static inline void add_attr(struct nlmsghdr *nlh, uint16_t type, size_t len, const void *data)
        !            55: {
        !            56:   struct nlattr *attr = (void *)nlh + NL_ALIGN(nlh->nlmsg_len);
        !            57:   uint16_t payload_len = NL_ALIGN(sizeof(struct nlattr)) + len;
        !            58:   attr->nla_type = type;
        !            59:   attr->nla_len = payload_len;
        !            60:   memcpy((void *)attr + NL_ALIGN(sizeof(struct nlattr)), data, len);
        !            61:   nlh->nlmsg_len += NL_ALIGN(payload_len);
        !            62: }
        !            63: 
        !            64: void ipset_init(void)
        !            65: {
        !            66:   struct utsname utsname;
        !            67:   int version;
        !            68:   char *split;
        !            69:   
        !            70:   if (uname(&utsname) < 0)
        !            71:     die(_("failed to find kernel version: %s"), NULL, EC_MISC);
        !            72:   
        !            73:   split = strtok(utsname.release, ".");
        !            74:   version = (split ? atoi(split) : 0);
        !            75:   split = strtok(NULL, ".");
        !            76:   version = version * 256 + (split ? atoi(split) : 0);
        !            77:   split = strtok(NULL, ".");
        !            78:   version = version * 256 + (split ? atoi(split) : 0);
        !            79:   old_kernel = (version < KERNEL_VERSION(2,6,32));
        !            80:   
        !            81:   if (old_kernel && (ipset_sock = socket(AF_INET, SOCK_RAW, IPPROTO_RAW)) != -1)
        !            82:     return;
        !            83:   
        !            84:   if (!old_kernel && 
        !            85:       (buffer = safe_malloc(BUFF_SZ)) &&
        !            86:       (ipset_sock = socket(AF_NETLINK, SOCK_RAW, NETLINK_NETFILTER)) != -1 &&
        !            87:       (bind(ipset_sock, (struct sockaddr *)&snl, sizeof(snl)) != -1))
        !            88:     return;
        !            89:   
        !            90:   die (_("failed to create IPset control socket: %s"), NULL, EC_MISC);
        !            91: }
        !            92: 
        !            93: static int new_add_to_ipset(const char *setname, const struct all_addr *ipaddr, int af, int remove)
        !            94: {
        !            95:   struct nlmsghdr *nlh;
        !            96:   struct nfgenmsg *nfg;
        !            97:   struct nlattr *nested[2];
        !            98:   uint8_t proto;
        !            99:   int addrsz = INADDRSZ;
        !           100:   ssize_t rc;
        !           101: 
        !           102: #ifdef HAVE_IPV6
        !           103:   if (af == AF_INET6)
        !           104:     addrsz = IN6ADDRSZ;
        !           105: #endif
        !           106:     
        !           107:   if (strlen(setname) >= IPSET_MAXNAMELEN) 
        !           108:     {
        !           109:       errno = ENAMETOOLONG;
        !           110:       return -1;
        !           111:     }
        !           112:   
        !           113:   memset(buffer, 0, sizeof(buffer));
        !           114: 
        !           115:   nlh = (struct nlmsghdr *)buffer;
        !           116:   nlh->nlmsg_len = NL_ALIGN(sizeof(struct nlmsghdr));
        !           117:   nlh->nlmsg_type = (remove ? IPSET_CMD_DEL : IPSET_CMD_ADD) | (NFNL_SUBSYS_IPSET << 8);
        !           118:   nlh->nlmsg_flags = NLM_F_REQUEST;
        !           119:   
        !           120:   nfg = (struct nfgenmsg *)(buffer + nlh->nlmsg_len);
        !           121:   nlh->nlmsg_len += NL_ALIGN(sizeof(struct nfgenmsg));
        !           122:   nfg->nfgen_family = af;
        !           123:   nfg->version = NFNETLINK_V0;
        !           124:   nfg->res_id = htons(0);
        !           125:   
        !           126:   proto = IPSET_PROTOCOL;
        !           127:   add_attr(nlh, IPSET_ATTR_PROTOCOL, sizeof(proto), &proto);
        !           128:   add_attr(nlh, IPSET_ATTR_SETNAME, strlen(setname) + 1, setname);
        !           129:   nested[0] = (struct nlattr *)(buffer + NL_ALIGN(nlh->nlmsg_len));
        !           130:   nlh->nlmsg_len += NL_ALIGN(sizeof(struct nlattr));
        !           131:   nested[0]->nla_type = NLA_F_NESTED | IPSET_ATTR_DATA;
        !           132:   nested[1] = (struct nlattr *)(buffer + NL_ALIGN(nlh->nlmsg_len));
        !           133:   nlh->nlmsg_len += NL_ALIGN(sizeof(struct nlattr));
        !           134:   nested[1]->nla_type = NLA_F_NESTED | IPSET_ATTR_IP;
        !           135:   add_attr(nlh, 
        !           136:           (af == AF_INET ? IPSET_ATTR_IPADDR_IPV4 : IPSET_ATTR_IPADDR_IPV6) | NLA_F_NET_BYTEORDER,
        !           137:           addrsz, &ipaddr->addr);
        !           138:   nested[1]->nla_len = (void *)buffer + NL_ALIGN(nlh->nlmsg_len) - (void *)nested[1];
        !           139:   nested[0]->nla_len = (void *)buffer + NL_ALIGN(nlh->nlmsg_len) - (void *)nested[0];
        !           140:        
        !           141:   while ((rc = sendto(ipset_sock, buffer, nlh->nlmsg_len, 0,
        !           142:                      (struct sockaddr *)&snl, sizeof(snl))) == -1 && retry_send());
        !           143:   return rc;
        !           144: }
        !           145: 
        !           146: 
        !           147: static int old_add_to_ipset(const char *setname, const struct all_addr *ipaddr, int remove)
        !           148: {
        !           149:   socklen_t size;
        !           150:   struct ip_set_req_adt_get {
        !           151:     unsigned op;
        !           152:     unsigned version;
        !           153:     union {
        !           154:       char name[IPSET_MAXNAMELEN];
        !           155:       uint16_t index;
        !           156:     } set;
        !           157:     char typename[IPSET_MAXNAMELEN];
        !           158:   } req_adt_get;
        !           159:   struct ip_set_req_adt {
        !           160:     unsigned op;
        !           161:     uint16_t index;
        !           162:     uint32_t ip;
        !           163:   } req_adt;
        !           164:   
        !           165:   if (strlen(setname) >= sizeof(req_adt_get.set.name)) 
        !           166:     {
        !           167:       errno = ENAMETOOLONG;
        !           168:       return -1;
        !           169:     }
        !           170:   
        !           171:   req_adt_get.op = 0x10;
        !           172:   req_adt_get.version = 3;
        !           173:   strcpy(req_adt_get.set.name, setname);
        !           174:   size = sizeof(req_adt_get);
        !           175:   if (getsockopt(ipset_sock, SOL_IP, 83, &req_adt_get, &size) < 0)
        !           176:     return -1;
        !           177:   req_adt.op = remove ? 0x102 : 0x101;
        !           178:   req_adt.index = req_adt_get.set.index;
        !           179:   req_adt.ip = ntohl(ipaddr->addr.addr4.s_addr);
        !           180:   if (setsockopt(ipset_sock, SOL_IP, 83, &req_adt, sizeof(req_adt)) < 0)
        !           181:     return -1;
        !           182:   
        !           183:   return 0;
        !           184: }
        !           185: 
        !           186: 
        !           187: 
        !           188: int add_to_ipset(const char *setname, const struct all_addr *ipaddr, int flags, int remove)
        !           189: {
        !           190:   int af = AF_INET;
        !           191: 
        !           192: #ifdef HAVE_IPV6
        !           193:   if (flags & F_IPV6)
        !           194:     {
        !           195:       af = AF_INET6;
        !           196:       /* old method only supports IPv4 */
        !           197:       if (old_kernel)
        !           198:        return -1;
        !           199:     }
        !           200: #endif
        !           201:   
        !           202:   return old_kernel ? old_add_to_ipset(setname, ipaddr, remove) : new_add_to_ipset(setname, ipaddr, af, remove);
        !           203: }
        !           204: 
        !           205: #endif

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