Annotation of embedaddon/dnsmasq/src/bpf.c, revision 1.1.1.2
1.1.1.2 ! misho 1: /* dnsmasq is Copyright (c) 2000-2014 Simon Kelley
1.1 misho 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: #if defined(HAVE_BSD_NETWORK) || defined(HAVE_SOLARIS_NETWORK)
20: #include <ifaddrs.h>
21:
22: #include <sys/param.h>
23: #include <sys/sysctl.h>
1.1.1.2 ! misho 24: #include <net/if.h>
1.1 misho 25: #include <net/route.h>
26: #include <net/if_dl.h>
27: #include <netinet/if_ether.h>
1.1.1.2 ! misho 28: #if defined(__FreeBSD__)
! 29: # include <net/if_var.h>
! 30: #endif
! 31: #include <netinet/in_var.h>
! 32: #ifdef HAVE_IPV6
! 33: # include <netinet6/in6_var.h>
! 34: #endif
1.1 misho 35:
36: #ifndef SA_SIZE
37: #define SA_SIZE(sa) \
38: ( (!(sa) || ((struct sockaddr *)(sa))->sa_len == 0) ? \
39: sizeof(long) : \
40: 1 + ( (((struct sockaddr *)(sa))->sa_len - 1) | (sizeof(long) - 1) ) )
41: #endif
42:
1.1.1.2 ! misho 43: #ifdef HAVE_BSD_NETWORK
! 44: static int del_family = 0;
! 45: static struct all_addr del_addr;
! 46: #endif
! 47:
! 48: #if defined(HAVE_BSD_NETWORK) && !defined(__APPLE__)
! 49:
1.1 misho 50: int arp_enumerate(void *parm, int (*callback)())
51: {
52: int mib[6];
53: size_t needed;
54: char *next;
55: struct rt_msghdr *rtm;
56: struct sockaddr_inarp *sin2;
57: struct sockaddr_dl *sdl;
58: struct iovec buff;
59: int rc;
60:
61: buff.iov_base = NULL;
62: buff.iov_len = 0;
63:
64: mib[0] = CTL_NET;
65: mib[1] = PF_ROUTE;
66: mib[2] = 0;
67: mib[3] = AF_INET;
68: mib[4] = NET_RT_FLAGS;
69: #ifdef RTF_LLINFO
70: mib[5] = RTF_LLINFO;
71: #else
72: mib[5] = 0;
73: #endif
74: if (sysctl(mib, 6, NULL, &needed, NULL, 0) == -1 || needed == 0)
75: return 0;
76:
77: while (1)
78: {
79: if (!expand_buf(&buff, needed))
80: return 0;
81: if ((rc = sysctl(mib, 6, buff.iov_base, &needed, NULL, 0)) == 0 ||
82: errno != ENOMEM)
83: break;
84: needed += needed / 8;
85: }
86: if (rc == -1)
87: return 0;
88:
89: for (next = buff.iov_base ; next < (char *)buff.iov_base + needed; next += rtm->rtm_msglen)
90: {
91: rtm = (struct rt_msghdr *)next;
92: sin2 = (struct sockaddr_inarp *)(rtm + 1);
93: sdl = (struct sockaddr_dl *)((char *)sin2 + SA_SIZE(sin2));
94: if (!(*callback)(AF_INET, &sin2->sin_addr, LLADDR(sdl), sdl->sdl_alen, parm))
95: return 0;
96: }
97:
98: return 1;
99: }
1.1.1.2 ! misho 100: #endif /* defined(HAVE_BSD_NETWORK) && !defined(__APPLE__) */
1.1 misho 101:
102:
103: int iface_enumerate(int family, void *parm, int (*callback)())
104: {
105: struct ifaddrs *head, *addrs;
1.1.1.2 ! misho 106: int errsav, fd = -1, ret = 0;
1.1 misho 107:
108: if (family == AF_UNSPEC)
109: #if defined(HAVE_BSD_NETWORK) && !defined(__APPLE__)
110: return arp_enumerate(parm, callback);
111: #else
112: return 0; /* need code for Solaris and MacOS*/
113: #endif
114:
115: /* AF_LINK doesn't exist in Linux, so we can't use it in our API */
116: if (family == AF_LOCAL)
117: family = AF_LINK;
118:
119: if (getifaddrs(&head) == -1)
120: return 0;
121:
1.1.1.2 ! misho 122: #if defined(HAVE_BSD_NETWORK) && defined(HAVE_IPV6)
! 123: if (family == AF_INET6)
! 124: fd = socket(PF_INET6, SOCK_DGRAM, 0);
! 125: #endif
! 126:
1.1 misho 127: for (addrs = head; addrs; addrs = addrs->ifa_next)
128: {
129: if (addrs->ifa_addr->sa_family == family)
130: {
131: int iface_index = if_nametoindex(addrs->ifa_name);
132:
1.1.1.2 ! misho 133: if (iface_index == 0 || !addrs->ifa_addr ||
! 134: (!addrs->ifa_netmask && family != AF_LINK))
1.1 misho 135: continue;
136:
137: if (family == AF_INET)
138: {
139: struct in_addr addr, netmask, broadcast;
140: addr = ((struct sockaddr_in *) addrs->ifa_addr)->sin_addr;
1.1.1.2 ! misho 141: #ifdef HAVE_BSD_NETWORK
! 142: if (del_family == AF_INET && del_addr.addr.addr4.s_addr == addr.s_addr)
! 143: continue;
! 144: #endif
1.1 misho 145: netmask = ((struct sockaddr_in *) addrs->ifa_netmask)->sin_addr;
146: if (addrs->ifa_broadaddr)
147: broadcast = ((struct sockaddr_in *) addrs->ifa_broadaddr)->sin_addr;
148: else
149: broadcast.s_addr = 0;
1.1.1.2 ! misho 150: if (!((*callback)(addr, iface_index, NULL, netmask, broadcast, parm)))
1.1 misho 151: goto err;
152: }
153: #ifdef HAVE_IPV6
154: else if (family == AF_INET6)
155: {
156: struct in6_addr *addr = &((struct sockaddr_in6 *) addrs->ifa_addr)->sin6_addr;
157: unsigned char *netmask = (unsigned char *) &((struct sockaddr_in6 *) addrs->ifa_netmask)->sin6_addr;
158: int scope_id = ((struct sockaddr_in6 *) addrs->ifa_addr)->sin6_scope_id;
159: int i, j, prefix = 0;
1.1.1.2 ! misho 160: u32 valid = 0xffffffff, preferred = 0xffffffff;
! 161: int flags = 0;
! 162: #ifdef HAVE_BSD_NETWORK
! 163: if (del_family == AF_INET6 && IN6_ARE_ADDR_EQUAL(&del_addr.addr.addr6, addr))
! 164: continue;
! 165: #endif
! 166: #if defined(HAVE_BSD_NETWORK) && !defined(__APPLE__)
! 167: struct in6_ifreq ifr6;
! 168:
! 169: memset(&ifr6, 0, sizeof(ifr6));
! 170: strncpy(ifr6.ifr_name, addrs->ifa_name, sizeof(ifr6.ifr_name));
! 171:
! 172: ifr6.ifr_addr = *((struct sockaddr_in6 *) addrs->ifa_addr);
! 173: if (fd != -1 && ioctl(fd, SIOCGIFAFLAG_IN6, &ifr6) != -1)
! 174: {
! 175: if (ifr6.ifr_ifru.ifru_flags6 & IN6_IFF_TENTATIVE)
! 176: flags |= IFACE_TENTATIVE;
! 177:
! 178: if (ifr6.ifr_ifru.ifru_flags6 & IN6_IFF_DEPRECATED)
! 179: flags |= IFACE_DEPRECATED;
! 180:
! 181: #ifdef IN6_IFF_TEMPORARY
! 182: if (!(ifr6.ifr_ifru.ifru_flags6 & (IN6_IFF_AUTOCONF | IN6_IFF_TEMPORARY)))
! 183: flags |= IFACE_PERMANENT;
! 184: #endif
! 185:
! 186: #ifdef IN6_IFF_PRIVACY
! 187: if (!(ifr6.ifr_ifru.ifru_flags6 & (IN6_IFF_AUTOCONF | IN6_IFF_PRIVACY)))
! 188: flags |= IFACE_PERMANENT;
! 189: #endif
! 190: }
1.1 misho 191:
1.1.1.2 ! misho 192: ifr6.ifr_addr = *((struct sockaddr_in6 *) addrs->ifa_addr);
! 193: if (fd != -1 && ioctl(fd, SIOCGIFALIFETIME_IN6, &ifr6) != -1)
! 194: {
! 195: valid = ifr6.ifr_ifru.ifru_lifetime.ia6t_vltime;
! 196: preferred = ifr6.ifr_ifru.ifru_lifetime.ia6t_pltime;
! 197: }
! 198: #endif
! 199:
1.1 misho 200: for (i = 0; i < IN6ADDRSZ; i++, prefix += 8)
201: if (netmask[i] != 0xff)
202: break;
1.1.1.2 ! misho 203:
1.1 misho 204: if (i != IN6ADDRSZ && netmask[i])
205: for (j = 7; j > 0; j--, prefix++)
206: if ((netmask[i] & (1 << j)) == 0)
207: break;
208:
209: /* voodoo to clear interface field in address */
210: if (!option_bool(OPT_NOWILD) && IN6_IS_ADDR_LINKLOCAL(addr))
211: {
212: addr->s6_addr[2] = 0;
213: addr->s6_addr[3] = 0;
1.1.1.2 ! misho 214: }
! 215:
! 216: if (!((*callback)(addr, prefix, scope_id, iface_index, flags,
! 217: (int) preferred, (int)valid, parm)))
! 218: goto err;
! 219: }
! 220: #endif /* HAVE_IPV6 */
! 221:
1.1 misho 222: #ifdef HAVE_DHCP6
223: else if (family == AF_LINK)
224: {
225: /* Assume ethernet again here */
226: struct sockaddr_dl *sdl = (struct sockaddr_dl *) addrs->ifa_addr;
227: if (sdl->sdl_alen != 0 &&
228: !((*callback)(iface_index, ARPHRD_ETHER, LLADDR(sdl), sdl->sdl_alen, parm)))
229: goto err;
230: }
231: #endif
232: }
233: }
234:
235: ret = 1;
236:
237: err:
238: errsav = errno;
1.1.1.2 ! misho 239: freeifaddrs(head);
! 240: if (fd != -1)
! 241: close(fd);
1.1 misho 242: errno = errsav;
243:
244: return ret;
245: }
1.1.1.2 ! misho 246: #endif /* defined(HAVE_BSD_NETWORK) || defined(HAVE_SOLARIS_NETWORK) */
1.1 misho 247:
248:
249: #if defined(HAVE_BSD_NETWORK) && defined(HAVE_DHCP)
250: #include <net/bpf.h>
251:
252: void init_bpf(void)
253: {
254: int i = 0;
255:
256: while (1)
257: {
258: sprintf(daemon->dhcp_buff, "/dev/bpf%d", i++);
259: if ((daemon->dhcp_raw_fd = open(daemon->dhcp_buff, O_RDWR, 0)) != -1)
260: return;
261:
262: if (errno != EBUSY)
263: die(_("cannot create DHCP BPF socket: %s"), NULL, EC_BADNET);
264: }
265: }
266:
267: void send_via_bpf(struct dhcp_packet *mess, size_t len,
268: struct in_addr iface_addr, struct ifreq *ifr)
269: {
270: /* Hairy stuff, packet either has to go to the
271: net broadcast or the destination can't reply to ARP yet,
272: but we do know the physical address.
273: Build the packet by steam, and send directly, bypassing
274: the kernel IP stack */
275:
276: struct ether_header ether;
277: struct ip ip;
278: struct udphdr {
279: u16 uh_sport; /* source port */
280: u16 uh_dport; /* destination port */
281: u16 uh_ulen; /* udp length */
282: u16 uh_sum; /* udp checksum */
283: } udp;
284:
285: u32 i, sum;
286: struct iovec iov[4];
287:
288: /* Only know how to do ethernet on *BSD */
289: if (mess->htype != ARPHRD_ETHER || mess->hlen != ETHER_ADDR_LEN)
290: {
291: my_syslog(MS_DHCP | LOG_WARNING, _("DHCP request for unsupported hardware type (%d) received on %s"),
292: mess->htype, ifr->ifr_name);
293: return;
294: }
295:
296: ifr->ifr_addr.sa_family = AF_LINK;
297: if (ioctl(daemon->dhcpfd, SIOCGIFADDR, ifr) < 0)
298: return;
299:
300: memcpy(ether.ether_shost, LLADDR((struct sockaddr_dl *)&ifr->ifr_addr), ETHER_ADDR_LEN);
301: ether.ether_type = htons(ETHERTYPE_IP);
302:
303: if (ntohs(mess->flags) & 0x8000)
304: {
305: memset(ether.ether_dhost, 255, ETHER_ADDR_LEN);
306: ip.ip_dst.s_addr = INADDR_BROADCAST;
307: }
308: else
309: {
310: memcpy(ether.ether_dhost, mess->chaddr, ETHER_ADDR_LEN);
311: ip.ip_dst.s_addr = mess->yiaddr.s_addr;
312: }
313:
314: ip.ip_p = IPPROTO_UDP;
315: ip.ip_src.s_addr = iface_addr.s_addr;
316: ip.ip_len = htons(sizeof(struct ip) +
317: sizeof(struct udphdr) +
318: len) ;
319: ip.ip_hl = sizeof(struct ip) / 4;
320: ip.ip_v = IPVERSION;
321: ip.ip_tos = 0;
322: ip.ip_id = htons(0);
323: ip.ip_off = htons(0x4000); /* don't fragment */
324: ip.ip_ttl = IPDEFTTL;
325: ip.ip_sum = 0;
326: for (sum = 0, i = 0; i < sizeof(struct ip) / 2; i++)
327: sum += ((u16 *)&ip)[i];
328: while (sum>>16)
329: sum = (sum & 0xffff) + (sum >> 16);
330: ip.ip_sum = (sum == 0xffff) ? sum : ~sum;
331:
332: udp.uh_sport = htons(daemon->dhcp_server_port);
333: udp.uh_dport = htons(daemon->dhcp_client_port);
334: if (len & 1)
335: ((char *)mess)[len] = 0; /* for checksum, in case length is odd. */
336: udp.uh_sum = 0;
337: udp.uh_ulen = sum = htons(sizeof(struct udphdr) + len);
338: sum += htons(IPPROTO_UDP);
339: sum += ip.ip_src.s_addr & 0xffff;
340: sum += (ip.ip_src.s_addr >> 16) & 0xffff;
341: sum += ip.ip_dst.s_addr & 0xffff;
342: sum += (ip.ip_dst.s_addr >> 16) & 0xffff;
343: for (i = 0; i < sizeof(struct udphdr)/2; i++)
344: sum += ((u16 *)&udp)[i];
345: for (i = 0; i < (len + 1) / 2; i++)
346: sum += ((u16 *)mess)[i];
347: while (sum>>16)
348: sum = (sum & 0xffff) + (sum >> 16);
349: udp.uh_sum = (sum == 0xffff) ? sum : ~sum;
350:
351: ioctl(daemon->dhcp_raw_fd, BIOCSETIF, ifr);
352:
353: iov[0].iov_base = ðer;
354: iov[0].iov_len = sizeof(ether);
355: iov[1].iov_base = &ip;
356: iov[1].iov_len = sizeof(ip);
357: iov[2].iov_base = &udp;
358: iov[2].iov_len = sizeof(udp);
359: iov[3].iov_base = mess;
360: iov[3].iov_len = len;
361:
362: while (writev(daemon->dhcp_raw_fd, iov, 4) == -1 && retry_send());
363: }
364:
1.1.1.2 ! misho 365: #endif /* defined(HAVE_BSD_NETWORK) && defined(HAVE_DHCP) */
! 366:
! 367:
! 368: #ifdef HAVE_BSD_NETWORK
! 369:
! 370: void route_init(void)
! 371: {
! 372: /* AF_UNSPEC: all addr families */
! 373: daemon->routefd = socket(PF_ROUTE, SOCK_RAW, AF_UNSPEC);
! 374:
! 375: if (daemon->routefd == -1 || !fix_fd(daemon->routefd))
! 376: die(_("cannot create PF_ROUTE socket: %s"), NULL, EC_BADNET);
! 377: }
! 378:
! 379: void route_sock(time_t now)
! 380: {
! 381: struct if_msghdr *msg;
! 382: int rc = recv(daemon->routefd, daemon->packet, daemon->packet_buff_sz, 0);
! 383:
! 384: if (rc < 4)
! 385: return;
! 386:
! 387: msg = (struct if_msghdr *)daemon->packet;
! 388:
! 389: if (rc < msg->ifm_msglen)
! 390: return;
! 391:
! 392: if (msg->ifm_version != RTM_VERSION)
! 393: {
! 394: static int warned = 0;
! 395: if (!warned)
! 396: {
! 397: my_syslog(LOG_WARNING, _("Unknown protocol version from route socket"));
! 398: warned = 1;
! 399: }
! 400: }
! 401: else if (msg->ifm_type == RTM_NEWADDR)
! 402: {
! 403: del_family = 0;
! 404: newaddress(now);
! 405: }
! 406: else if (msg->ifm_type == RTM_DELADDR)
! 407: {
! 408: /* There's a race in the kernel, such that if we run iface_enumerate() immediately
! 409: we get a DELADDR event, the deleted address still appears. Here we store the deleted address
! 410: in a static variable, and omit it from the set returned by iface_enumerate() */
! 411: int mask = ((struct ifa_msghdr *)msg)->ifam_addrs;
! 412: int maskvec[] = { RTA_DST, RTA_GATEWAY, RTA_NETMASK, RTA_GENMASK,
! 413: RTA_IFP, RTA_IFA, RTA_AUTHOR, RTA_BRD };
! 414: int of;
! 415: unsigned int i;
! 416:
! 417: for (i = 0, of = sizeof(struct ifa_msghdr); of < rc && i < sizeof(maskvec)/sizeof(maskvec[0]); i++)
! 418: if (mask & maskvec[i])
! 419: {
! 420: struct sockaddr *sa = (struct sockaddr *)((char *)msg + of);
! 421: size_t diff = (sa->sa_len != 0) ? sa->sa_len : sizeof(long);
! 422:
! 423: if (maskvec[i] == RTA_IFA)
! 424: {
! 425: del_family = sa->sa_family;
! 426: if (del_family == AF_INET)
! 427: del_addr.addr.addr4 = ((struct sockaddr_in *)sa)->sin_addr;
! 428: #ifdef HAVE_IPV6
! 429: else if (del_family == AF_INET6)
! 430: del_addr.addr.addr6 = ((struct sockaddr_in6 *)sa)->sin6_addr;
1.1 misho 431: #endif
1.1.1.2 ! misho 432: else
! 433: del_family = 0;
! 434: }
! 435:
! 436: of += diff;
! 437: /* round up as needed */
! 438: if (diff & (sizeof(long) - 1))
! 439: of += sizeof(long) - (diff & (sizeof(long) - 1));
! 440: }
! 441:
! 442: newaddress(now);
! 443: }
! 444: }
! 445:
! 446: #endif /* HAVE_BSD_NETWORK */
1.1 misho 447:
448:
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