diff options
| -rw-r--r-- | usr.sbin/ppp/arp.c | 145 |
1 files changed, 80 insertions, 65 deletions
diff --git a/usr.sbin/ppp/arp.c b/usr.sbin/ppp/arp.c index 08244d2..963c154 100644 --- a/usr.sbin/ppp/arp.c +++ b/usr.sbin/ppp/arp.c @@ -17,7 +17,7 @@ * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE. * - * $Id: arp.c,v 1.23 1998/01/19 22:34:20 brian Exp $ + * $Id: arp.c,v 1.24 1998/01/21 12:52:14 brian Exp $ * */ @@ -34,6 +34,7 @@ #include <netinet/in.h> #include <net/if_types.h> #include <netinet/if_ether.h> +#include <arpa/inet.h> #include <fcntl.h> #include <stdio.h> @@ -65,7 +66,7 @@ * and type ``make arp-test''. * */ -#define LogIsKept(x) 0 +#define LogIsKept(x) 1 #define LogPrintf fprintf #undef LogDEBUG #define LogDEBUG stderr @@ -240,90 +241,104 @@ cifproxyarp(int unit, struct in_addr hisaddr) * get_ether_addr - get the hardware address of an interface on the * the same subnet as ipaddr. */ -#define MAX_IFS 32 static int get_ether_addr(int s, struct in_addr ipaddr, struct sockaddr_dl *hwaddr) { - int idx; - const char *got; - char *sp, *ep, *cp, *wp; - struct ifreq ifrq; - struct in_addr addr, mask; - struct rt_msghdr *rtm; - struct sockaddr *sa_dst, *sa_gw; - struct sockaddr_dl *dl; + int mib[6], sa_len, skip, b; size_t needed; - int mib[6]; - - idx = 1; - while (strcmp(got = Index2Nam(idx), "???")) { - strncpy(ifrq.ifr_name, got, sizeof ifrq.ifr_name - 1); - ifrq.ifr_name[sizeof ifrq.ifr_name - 1] = '\0'; - if (ID0ioctl(s, SIOCGIFADDR, &ifrq) == 0 && - ifrq.ifr_addr.sa_family == AF_INET) { - addr = ((struct sockaddr_in *)&ifrq.ifr_addr)->sin_addr; - if (ID0ioctl(s, SIOCGIFNETMASK, &ifrq) == 0) { - mask = ((struct sockaddr_in *)&ifrq.ifr_broadaddr)->sin_addr; - if ((ipaddr.s_addr & mask.s_addr) == (addr.s_addr & mask.s_addr)) - break; - } - } - idx++; - } - - if (!strcmp(got, "???")) - return 0; - - LogPrintf(LogPHASE, "Found interface %s for proxy arp\n", got); + char *buf, *ptr, *end; + struct if_msghdr *ifm; + struct ifa_msghdr *ifam; + struct sockaddr *sa; + struct sockaddr_dl *dl; + struct sockaddr_in *ifa, *mask; mib[0] = CTL_NET; mib[1] = PF_ROUTE; mib[2] = 0; mib[3] = 0; - mib[4] = NET_RT_DUMP; + mib[4] = NET_RT_IFLIST; mib[5] = 0; + if (sysctl(mib, 6, NULL, &needed, NULL, 0) < 0) { - LogPrintf(LogERROR, "get_ether_addr: sysctl: estimate: %s\n", - strerror(errno)); + LogPrintf(LogERROR, "Index2Nam: sysctl: estimate: %s\n", strerror(errno)); return 0; } - if (needed < 0) + + if ((buf = malloc(needed)) == NULL) return 0; - if ((sp = malloc(needed)) == NULL) + + if (sysctl(mib, 6, buf, &needed, NULL, 0) < 0) { + free(buf); return 0; - if (sysctl(mib, 6, sp, &needed, NULL, 0) < 0) { - LogPrintf(LogERROR, "ShowRoute: sysctl: getroute: %s\n", strerror(errno)); - free(sp); - return (1); } - ep = sp + needed; - - for (cp = sp; cp < ep; cp += rtm->rtm_msglen) { - rtm = (struct rt_msghdr *) cp; - if (rtm->rtm_index == idx) { - wp = (char *)(rtm+1); - - if (rtm->rtm_addrs & RTA_DST) { - sa_dst = (struct sockaddr *)wp; - wp += sa_dst->sa_len; - } else - sa_dst = NULL; - - if (rtm->rtm_addrs & RTA_GATEWAY) { - sa_gw = (struct sockaddr *)wp; - if (sa_gw->sa_family == AF_LINK) { - dl = (struct sockaddr_dl *)wp; - if (!dl->sdl_nlen && !dl->sdl_alen && !dl->sdl_slen) { - memcpy(hwaddr, dl, dl->sdl_len); - free(sp); - return 1; - } + end = buf + needed; + + ptr = buf; + while (ptr < end) { + ifm = (struct if_msghdr *)ptr; /* On if_msghdr */ + if (ifm->ifm_type != RTM_IFINFO) + break; + dl = (struct sockaddr_dl *)(ifm + 1); /* Single _dl at end */ + skip = (ifm->ifm_flags & (IFF_UP | IFF_BROADCAST | IFF_POINTOPOINT | + IFF_NOARP | IFF_LOOPBACK)) != (IFF_UP | IFF_BROADCAST); + ptr += ifm->ifm_msglen; /* First ifa_msghdr */ + while (ptr < end) { + ifam = (struct ifa_msghdr *)ptr; /* Next ifa_msghdr (alias) */ + if (ifam->ifam_type != RTM_NEWADDR) /* finished ? */ + break; + sa = (struct sockaddr *)(ifam+1); /* pile of sa's at end */ + ptr += ifam->ifam_msglen; + if (skip || (ifam->ifam_addrs & (RTA_NETMASK|RTA_IFA)) != + (RTA_NETMASK|RTA_IFA)) + continue; + /* Found a candidate. Do the addresses match ? */ + if (LogIsKept(LogDEBUG) && + ptr == (char *)ifm + ifm->ifm_msglen + ifam->ifam_msglen) + LogPrintf(LogDEBUG, "%.*s interface is a candidate for proxy\n", + dl->sdl_nlen, dl->sdl_data); + b = 1; + while (b < (RTA_NETMASK|RTA_IFA) && sa < (struct sockaddr *)ptr) { + switch (b) { + case RTA_IFA: + ifa = (struct sockaddr_in *)sa; + break; + case RTA_NETMASK: + /* + * Careful here ! this sockaddr doesn't have sa_family set to + * AF_INET, and is only 8 bytes big ! I have no idea why ! + */ + mask = (struct sockaddr_in *)sa; + break; } + if (ifam->ifam_addrs & b) { +#define ALN sizeof(ifa->sin_addr.s_addr) + sa_len = sa->sa_len > 0 ? ((sa->sa_len-1)|(ALN-1))+1 : ALN; + sa = (struct sockaddr *)((char *)sa + sa_len); + } + b <<= 1; + } + if (LogIsKept(LogDEBUG)) { + char a[16]; + strncpy(a, inet_ntoa(mask->sin_addr), sizeof a - 1); + a[sizeof a - 1] = '\0'; + LogPrintf(LogDEBUG, "Check addr %s, mask %s\n", + inet_ntoa(ifa->sin_addr), a); + } + if (ifa->sin_family == AF_INET && + (ifa->sin_addr.s_addr & mask->sin_addr.s_addr) == + (ipaddr.s_addr & mask->sin_addr.s_addr)) { + LogPrintf(LogPHASE, "Found interface %.*s for proxy arp\n", + dl->sdl_alen, dl->sdl_data); + memcpy(hwaddr, dl, dl->sdl_len); + free(buf); + return 1; } } } - free(sp); + free(buf); + return 0; } |
