diff options
| -rw-r--r-- | usr.sbin/portmap/from_local.c | 131 |
1 files changed, 82 insertions, 49 deletions
diff --git a/usr.sbin/portmap/from_local.c b/usr.sbin/portmap/from_local.c index a1bfa72..b074444 100644 --- a/usr.sbin/portmap/from_local.c +++ b/usr.sbin/portmap/from_local.c @@ -40,7 +40,7 @@ static char sccsid[] = "@(#) from_local.c 1.2 93/11/16 21:50:02"; #endif static const char rcsid[] = - "$Id$"; + "$Id: from_local.c,v 1.5 1997/10/09 07:17:09 charnier Exp $"; #endif #ifdef TEST @@ -50,6 +50,7 @@ static const char rcsid[] = #include <sys/types.h> #include <sys/ioctl.h> #include <sys/socket.h> +#include <sys/sysctl.h> #include <sys/time.h> #include <netdb.h> @@ -57,6 +58,7 @@ static const char rcsid[] = #include <unistd.h> #include <net/if.h> +#include <net/if_dl.h> #include <netinet/in.h> #ifndef TRUE @@ -66,61 +68,92 @@ static const char rcsid[] = /* How many interfaces could there be on a computer? */ -#define MAX_LOCAL 256 /* overkill */ +#define ESTIMATED_LOCAL 20 static int num_local = -1; -static struct in_addr addrs[MAX_LOCAL]; +static struct in_addr *addrs; /* find_local - find all IP addresses for this host */ int find_local() { - struct ifconf ifc; - struct ifreq ifreq; - struct ifreq *ifr; - struct ifreq *the_end; - int sock; - char buf[MAX_LOCAL * sizeof(struct ifreq)]; - - /* Get list of network interfaces. */ - - if ((sock = socket(PF_INET, SOCK_DGRAM, 0)) < 0) { - perror("socket"); - return (0); - } - ifc.ifc_len = sizeof(buf); - ifc.ifc_buf = buf; - if (ioctl(sock, SIOCGIFCONF, (char *) &ifc) < 0) { - perror("SIOCGIFCONF"); - (void) close(sock); - return (0); - } - /* Get IP address of each active IP network interface. */ - - the_end = (struct ifreq *) (ifc.ifc_buf + ifc.ifc_len); - num_local = 0; - for (ifr = ifc.ifc_req; ifr < the_end; ifr++) { - if (ifr->ifr_addr.sa_family == AF_INET) { /* IP net interface */ - ifreq = *ifr; - if (ioctl(sock, SIOCGIFFLAGS, (char *) &ifreq) < 0) { - perror("SIOCGIFFLAGS"); - } else if (ifreq.ifr_flags & IFF_UP) { /* active interface */ - if (ioctl(sock, SIOCGIFADDR, (char *) &ifreq) < 0) { - perror("SIOCGIFADDR"); - } else { - addrs[num_local++] = ((struct sockaddr_in *) - & ifreq.ifr_addr)->sin_addr; - } - } - } - if (num_local >= MAX_LOCAL) - break; - /* Support for variable-length addresses. */ - ifr = (struct ifreq *) ((caddr_t) ifr - + ifr->ifr_addr.sa_len - sizeof(struct sockaddr)); - } - (void) close(sock); - return (num_local); + int mib[6], n, s, alloced; + size_t needed; + char *buf, *end, *ptr; + struct if_msghdr *ifm; + struct ifreq ifr; + struct sockaddr_dl *dl; + + mib[0] = CTL_NET; + mib[1] = PF_ROUTE; + mib[4] = NET_RT_IFLIST; + mib[2] = mib[3] = mib[5] = 0; + + if ((s = socket(PF_INET, SOCK_DGRAM, 0)) < 0) { + perror("socket"); + return (0); + } + if (sysctl(mib, 6, NULL, &needed, NULL, 0) < 0) { + close(s); + perror("sysctl(NET_RT_IFLIST)"); + return 0; + } + if ((buf = (char *)malloc(needed)) == NULL) { + close(s); + perror("malloc"); + return 0; + } + if (sysctl(mib, 6, buf, &needed, NULL, 0) < 0) { + close(s); + free(buf); + perror("sysctl(NET_RT_IFLIST)(after malloc)"); + return 0; + } + + if (addrs) { + free(addrs); + addrs = NULL; + } + num_local = 0; + alloced = 0; + end = buf + needed; + + for (ptr = buf; ptr < end; ptr += ifm->ifm_msglen) { + ifm = (struct if_msghdr *)ptr; + dl = (struct sockaddr_dl *)(ifm + 1); + n = dl->sdl_nlen > sizeof ifr.ifr_name ? + sizeof ifr.ifr_name : dl->sdl_nlen; + if (n == 0) + continue; + strncpy(ifr.ifr_name, dl->sdl_data, n); + if (n < sizeof ifr.ifr_name) + ifr.ifr_name[n] = '\0'; + /* we only want the first address from each interface */ + if (ioctl(s, SIOCGIFFLAGS, &ifr) < 0) + perror("SIOCGIFFLAGS"); + else if (ifr.ifr_flags & IFF_UP) /* active interface */ + if (ioctl(s, SIOCGIFADDR, &ifr) < 0) + perror("SIOCGIFADDR"); + else { + if (alloced < num_local + 1) { + alloced += ESTIMATED_LOCAL; + if (addrs) + addrs = (struct in_addr *)realloc(addrs, alloced * sizeof addrs[0]); + else + addrs = (struct in_addr *)malloc(alloced * sizeof addrs[0]); + if (addrs == NULL) { + perror("malloc/realloc"); + num_local = 0; + break; + } + } + addrs[num_local++] = ((struct sockaddr_in *)&ifr.ifr_addr)->sin_addr; + } + } + free(buf); + close(s); + + return num_local; } /* from_local - determine whether request comes from the local system */ |
