Annotation of embedaddon/dnsmasq/src/ipset.c, revision 1.1.1.4

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: 
1.1.1.3   misho      19: #if defined(HAVE_IPSET) && defined(HAVE_LINUX_NETWORK)
1.1       misho      20: 
                     21: #include <string.h>
                     22: #include <errno.h>
                     23: #include <sys/types.h>
                     24: #include <sys/socket.h>
                     25: #include <arpa/inet.h>
                     26: #include <linux/netlink.h>
1.1.1.2   misho      27: 
                     28: /* We want to be able to compile against old header files
                     29:    Kernel version is handled at run-time. */
                     30: 
1.1       misho      31: #define NFNL_SUBSYS_IPSET 6
1.1.1.2   misho      32: 
1.1       misho      33: #define IPSET_ATTR_DATA 7
                     34: #define IPSET_ATTR_IP 1
                     35: #define IPSET_ATTR_IPADDR_IPV4 1
                     36: #define IPSET_ATTR_IPADDR_IPV6 2
                     37: #define IPSET_ATTR_PROTOCOL 1
                     38: #define IPSET_ATTR_SETNAME 2
                     39: #define IPSET_CMD_ADD 9
                     40: #define IPSET_CMD_DEL 10
                     41: #define IPSET_MAXNAMELEN 32
                     42: #define IPSET_PROTOCOL 6
1.1.1.2   misho      43: 
                     44: #ifndef NFNETLINK_V0
                     45: #define NFNETLINK_V0    0
                     46: #endif
                     47: 
                     48: #ifndef NLA_F_NESTED
                     49: #define NLA_F_NESTED           (1 << 15)
                     50: #endif
                     51: 
                     52: #ifndef NLA_F_NET_BYTEORDER
                     53: #define NLA_F_NET_BYTEORDER    (1 << 14)
1.1       misho      54: #endif
                     55: 
1.1.1.2   misho      56: struct my_nlattr {
                     57:         __u16           nla_len;
                     58:         __u16           nla_type;
                     59: };
                     60: 
                     61: struct my_nfgenmsg {
                     62:         __u8  nfgen_family;             /* AF_xxx */
                     63:         __u8  version;          /* nfnetlink version */
                     64:         __be16    res_id;               /* resource id */
                     65: };
                     66: 
                     67: 
1.1       misho      68: /* data structure size in here is fixed */
                     69: #define BUFF_SZ 256
                     70: 
                     71: #define NL_ALIGN(len) (((len)+3) & ~(3))
                     72: static const struct sockaddr_nl snl = { .nl_family = AF_NETLINK };
                     73: static int ipset_sock, old_kernel;
                     74: static char *buffer;
                     75: 
                     76: static inline void add_attr(struct nlmsghdr *nlh, uint16_t type, size_t len, const void *data)
                     77: {
1.1.1.2   misho      78:   struct my_nlattr *attr = (void *)nlh + NL_ALIGN(nlh->nlmsg_len);
                     79:   uint16_t payload_len = NL_ALIGN(sizeof(struct my_nlattr)) + len;
1.1       misho      80:   attr->nla_type = type;
                     81:   attr->nla_len = payload_len;
1.1.1.2   misho      82:   memcpy((void *)attr + NL_ALIGN(sizeof(struct my_nlattr)), data, len);
1.1       misho      83:   nlh->nlmsg_len += NL_ALIGN(payload_len);
                     84: }
                     85: 
                     86: void ipset_init(void)
                     87: {
1.1.1.4 ! misho      88:   old_kernel = (daemon->kernel_version < KERNEL_VERSION(2,6,32));
1.1       misho      89:   
                     90:   if (old_kernel && (ipset_sock = socket(AF_INET, SOCK_RAW, IPPROTO_RAW)) != -1)
                     91:     return;
                     92:   
                     93:   if (!old_kernel && 
                     94:       (buffer = safe_malloc(BUFF_SZ)) &&
                     95:       (ipset_sock = socket(AF_NETLINK, SOCK_RAW, NETLINK_NETFILTER)) != -1 &&
                     96:       (bind(ipset_sock, (struct sockaddr *)&snl, sizeof(snl)) != -1))
                     97:     return;
                     98:   
                     99:   die (_("failed to create IPset control socket: %s"), NULL, EC_MISC);
                    100: }
                    101: 
1.1.1.4 ! misho     102: static int new_add_to_ipset(const char *setname, const union all_addr *ipaddr, int af, int remove)
1.1       misho     103: {
                    104:   struct nlmsghdr *nlh;
1.1.1.2   misho     105:   struct my_nfgenmsg *nfg;
                    106:   struct my_nlattr *nested[2];
1.1       misho     107:   uint8_t proto;
1.1.1.4 ! misho     108:   int addrsz = (af == AF_INET6) ? IN6ADDRSZ : INADDRSZ;
1.1       misho     109: 
                    110:   if (strlen(setname) >= IPSET_MAXNAMELEN) 
                    111:     {
                    112:       errno = ENAMETOOLONG;
                    113:       return -1;
                    114:     }
                    115:   
1.1.1.2   misho     116:   memset(buffer, 0, BUFF_SZ);
1.1       misho     117: 
                    118:   nlh = (struct nlmsghdr *)buffer;
                    119:   nlh->nlmsg_len = NL_ALIGN(sizeof(struct nlmsghdr));
                    120:   nlh->nlmsg_type = (remove ? IPSET_CMD_DEL : IPSET_CMD_ADD) | (NFNL_SUBSYS_IPSET << 8);
                    121:   nlh->nlmsg_flags = NLM_F_REQUEST;
                    122:   
1.1.1.2   misho     123:   nfg = (struct my_nfgenmsg *)(buffer + nlh->nlmsg_len);
                    124:   nlh->nlmsg_len += NL_ALIGN(sizeof(struct my_nfgenmsg));
1.1       misho     125:   nfg->nfgen_family = af;
                    126:   nfg->version = NFNETLINK_V0;
                    127:   nfg->res_id = htons(0);
                    128:   
                    129:   proto = IPSET_PROTOCOL;
                    130:   add_attr(nlh, IPSET_ATTR_PROTOCOL, sizeof(proto), &proto);
                    131:   add_attr(nlh, IPSET_ATTR_SETNAME, strlen(setname) + 1, setname);
1.1.1.2   misho     132:   nested[0] = (struct my_nlattr *)(buffer + NL_ALIGN(nlh->nlmsg_len));
                    133:   nlh->nlmsg_len += NL_ALIGN(sizeof(struct my_nlattr));
1.1       misho     134:   nested[0]->nla_type = NLA_F_NESTED | IPSET_ATTR_DATA;
1.1.1.2   misho     135:   nested[1] = (struct my_nlattr *)(buffer + NL_ALIGN(nlh->nlmsg_len));
                    136:   nlh->nlmsg_len += NL_ALIGN(sizeof(struct my_nlattr));
1.1       misho     137:   nested[1]->nla_type = NLA_F_NESTED | IPSET_ATTR_IP;
                    138:   add_attr(nlh, 
                    139:           (af == AF_INET ? IPSET_ATTR_IPADDR_IPV4 : IPSET_ATTR_IPADDR_IPV6) | NLA_F_NET_BYTEORDER,
1.1.1.4 ! misho     140:           addrsz, ipaddr);
1.1       misho     141:   nested[1]->nla_len = (void *)buffer + NL_ALIGN(nlh->nlmsg_len) - (void *)nested[1];
                    142:   nested[0]->nla_len = (void *)buffer + NL_ALIGN(nlh->nlmsg_len) - (void *)nested[0];
                    143:        
1.1.1.3   misho     144:   while (retry_send(sendto(ipset_sock, buffer, nlh->nlmsg_len, 0,
                    145:                           (struct sockaddr *)&snl, sizeof(snl))));
                    146:                                                                    
                    147:   return errno == 0 ? 0 : -1;
1.1       misho     148: }
                    149: 
                    150: 
1.1.1.4 ! misho     151: static int old_add_to_ipset(const char *setname, const union all_addr *ipaddr, int remove)
1.1       misho     152: {
                    153:   socklen_t size;
                    154:   struct ip_set_req_adt_get {
                    155:     unsigned op;
                    156:     unsigned version;
                    157:     union {
                    158:       char name[IPSET_MAXNAMELEN];
                    159:       uint16_t index;
                    160:     } set;
                    161:     char typename[IPSET_MAXNAMELEN];
                    162:   } req_adt_get;
                    163:   struct ip_set_req_adt {
                    164:     unsigned op;
                    165:     uint16_t index;
                    166:     uint32_t ip;
                    167:   } req_adt;
                    168:   
                    169:   if (strlen(setname) >= sizeof(req_adt_get.set.name)) 
                    170:     {
                    171:       errno = ENAMETOOLONG;
                    172:       return -1;
                    173:     }
                    174:   
                    175:   req_adt_get.op = 0x10;
                    176:   req_adt_get.version = 3;
                    177:   strcpy(req_adt_get.set.name, setname);
                    178:   size = sizeof(req_adt_get);
                    179:   if (getsockopt(ipset_sock, SOL_IP, 83, &req_adt_get, &size) < 0)
                    180:     return -1;
                    181:   req_adt.op = remove ? 0x102 : 0x101;
                    182:   req_adt.index = req_adt_get.set.index;
1.1.1.4 ! misho     183:   req_adt.ip = ntohl(ipaddr->addr4.s_addr);
1.1       misho     184:   if (setsockopt(ipset_sock, SOL_IP, 83, &req_adt, sizeof(req_adt)) < 0)
                    185:     return -1;
                    186:   
                    187:   return 0;
                    188: }
                    189: 
                    190: 
                    191: 
1.1.1.4 ! misho     192: int add_to_ipset(const char *setname, const union all_addr *ipaddr, int flags, int remove)
1.1       misho     193: {
1.1.1.4 ! misho     194:   int ret = 0, af = AF_INET;
1.1       misho     195: 
                    196:   if (flags & F_IPV6)
                    197:     {
                    198:       af = AF_INET6;
                    199:       /* old method only supports IPv4 */
                    200:       if (old_kernel)
1.1.1.4 ! misho     201:        {
        !           202:          errno = EAFNOSUPPORT ;
        !           203:          ret = -1;
        !           204:        }
1.1       misho     205:     }
                    206:   
1.1.1.4 ! misho     207:   if (ret != -1) 
        !           208:     ret = old_kernel ? old_add_to_ipset(setname, ipaddr, remove) : new_add_to_ipset(setname, ipaddr, af, remove);
        !           209: 
        !           210:   if (ret == -1)
        !           211:      my_syslog(LOG_ERR, _("failed to update ipset %s: %s"), setname, strerror(errno));
        !           212: 
        !           213:   return ret;
1.1       misho     214: }
                    215: 
                    216: #endif

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