Changeset 1765 in MondoRescue for branches/2.2.5/mindi-busybox/networking/udhcp/arpping.c

Timestamp:

Nov 4, 2007, 3:16:40 AM (17 years ago)

Author:

Bruno Cornec

Message:

Update to busybox 1.7.2

File:

• branches/2.2.5/mindi-busybox/networking/udhcp/arpping.c (modified) (2 diffs)

branches/2.2.5/mindi-busybox/networking/udhcp/arpping.c

@@ +1 @@
+/* vi: set sw=4 ts=4: */
 /*
  * arpping.c
@@ -6 +7 @@
  */
 
-#include <time.h>
-#include <sys/socket.h>
 #include <netinet/if_ether.h>
 #include <net/if_arp.h>
-#include <netinet/in.h>
-#include <string.h>
-#include <unistd.h>
-#include <errno.h>
 
+#include "common.h"
 #include "dhcpd.h"
-#include "arpping.h"
-#include "common.h"
-
-/* args:    yiaddr - what IP to ping
- *      ip - our ip
- *      mac - our arp address
- *      interface - interface to use
- * retn:    1 addr free
- *      0 addr used
- *      -1 error
- */
-
-/* FIXME: match response against chaddr */
-int arpping(uint32_t yiaddr, uint32_t ip, uint8_t *mac, char *interface)
-{
-
-    int timeout = 2;
-    int optval = 1;
-    int s;          /* socket */
-    int rv = 1;         /* return value */
-    struct sockaddr addr;       /* for interface name */
-    struct arpMsg   arp;
-    fd_set      fdset;
-    struct timeval  tm;
-    time_t      prevTime;
 
 
-    if ((s = socket (PF_PACKET, SOCK_PACKET, htons(ETH_P_ARP))) == -1) {
-#ifdef IN_BUSYBOX
-        LOG(LOG_ERR, bb_msg_can_not_create_raw_socket);
-#else
-        LOG(LOG_ERR, "Could not open raw socket");
-#endif
+struct arpMsg {
+    /* Ethernet header */
+    uint8_t  h_dest[6];     /* 00 destination ether addr */
+    uint8_t  h_source[6];   /* 06 source ether addr */
+    uint16_t h_proto;       /* 0c packet type ID field */
+
+    /* ARP packet */
+    uint16_t htype;         /* 0e hardware type (must be ARPHRD_ETHER) */
+    uint16_t ptype;         /* 10 protocol type (must be ETH_P_IP) */
+    uint8_t  hlen;          /* 12 hardware address length (must be 6) */
+    uint8_t  plen;          /* 13 protocol address length (must be 4) */
+    uint16_t operation;     /* 14 ARP opcode */
+    uint8_t  sHaddr[6];     /* 16 sender's hardware address */
+    uint8_t  sInaddr[4];    /* 1c sender's IP address */
+    uint8_t  tHaddr[6];     /* 20 target's hardware address */
+    uint8_t  tInaddr[4];    /* 26 target's IP address */
+    uint8_t  pad[18];       /* 2a pad for min. ethernet payload (60 bytes) */
+} ATTRIBUTE_PACKED;
+
+
+/* Returns 1 if no reply received */
+
+int arpping(uint32_t test_ip, uint32_t from_ip, uint8_t *from_mac, const char *interface)
+{
+    int timeout = 2;
+    int s;                  /* socket */
+    int rv = 1;             /* "no reply received" yet */
+    struct sockaddr addr;   /* for interface name */
+    struct arpMsg arp;
+    fd_set fdset;
+    struct timeval tm;
+    unsigned prevTime;
+
+    s = socket(PF_PACKET, SOCK_PACKET, htons(ETH_P_ARP));
+    if (s == -1) {
+        bb_perror_msg(bb_msg_can_not_create_raw_socket);
         return -1;
     }
 
-    if (setsockopt(s, SOL_SOCKET, SO_BROADCAST, &optval, sizeof(optval)) == -1) {
-        LOG(LOG_ERR, "Could not setsocketopt on raw socket");
-        close(s);
-        return -1;
+    if (setsockopt_broadcast(s) == -1) {
+        bb_perror_msg("cannot setsocketopt on raw socket");
+        goto ret;
     }
 
     /* send arp request */
     memset(&arp, 0, sizeof(arp));
-    memcpy(arp.h_dest, MAC_BCAST_ADDR, 6);      /* MAC DA */
-    memcpy(arp.h_source, mac, 6);           /* MAC SA */
-    arp.h_proto = htons(ETH_P_ARP);         /* protocol type (Ethernet) */
-    arp.htype = htons(ARPHRD_ETHER);        /* hardware type */
-    arp.ptype = htons(ETH_P_IP);            /* protocol type (ARP message) */
-    arp.hlen = 6;                   /* hardware address length */
-    arp.plen = 4;                   /* protocol address length */
-    arp.operation = htons(ARPOP_REQUEST);       /* ARP op code */
-    memcpy(arp.sInaddr, &ip, sizeof(ip));       /* source IP address */
-    memcpy(arp.sHaddr, mac, 6);         /* source hardware address */
-    memcpy(arp.tInaddr, &yiaddr, sizeof(yiaddr));   /* target IP address */
+    memset(arp.h_dest, 0xff, 6);                    /* MAC DA */
+    memcpy(arp.h_source, from_mac, 6);              /* MAC SA */
+    arp.h_proto = htons(ETH_P_ARP);                 /* protocol type (Ethernet) */
+    arp.htype = htons(ARPHRD_ETHER);                /* hardware type */
+    arp.ptype = htons(ETH_P_IP);                    /* protocol type (ARP message) */
+    arp.hlen = 6;                                   /* hardware address length */
+    arp.plen = 4;                                   /* protocol address length */
+    arp.operation = htons(ARPOP_REQUEST);           /* ARP op code */
+    memcpy(arp.sHaddr, from_mac, 6);                /* source hardware address */
+    memcpy(arp.sInaddr, &from_ip, sizeof(from_ip)); /* source IP address */
+    /* tHaddr */                                    /* target hardware address */
+    memcpy(arp.tInaddr, &test_ip, sizeof(test_ip)); /* target IP address */
 
     memset(&addr, 0, sizeof(addr));
-    strcpy(addr.sa_data, interface);
+    safe_strncpy(addr.sa_data, interface, sizeof(addr.sa_data));
     if (sendto(s, &arp, sizeof(arp), 0, &addr, sizeof(addr)) < 0)
-        rv = 0;
+        goto ret;
 
-    /* wait arp reply, and check it */
-    tm.tv_usec = 0;
-    prevTime = uptime();
-    while (timeout > 0) {
+    /* wait for arp reply, and check it */
+    do {
+        int r;
+        prevTime = monotonic_sec();
         FD_ZERO(&fdset);
         FD_SET(s, &fdset);
         tm.tv_sec = timeout;
-        if (select(s + 1, &fdset, (fd_set *) NULL, (fd_set *) NULL, &tm) < 0) {
-            DEBUG(LOG_ERR, "Error on ARPING request: %m");
-            if (errno != EINTR) rv = 0;
-        } else if (FD_ISSET(s, &fdset)) {
-            if (recv(s, &arp, sizeof(arp), 0) < 0 ) rv = 0;
-            if (arp.operation == htons(ARPOP_REPLY) &&
-                memcmp(arp.tHaddr, mac, 6) == 0 &&
-                *((uint32_t *) arp.sInaddr) == yiaddr) {
-                DEBUG(LOG_INFO, "Valid arp reply receved for this address");
+        tm.tv_usec = 0;
+        r = select(s + 1, &fdset, NULL, NULL, &tm);
+        if (r < 0) {
+            bb_perror_msg("error on ARPING request");
+            if (errno != EINTR)
+                break;
+        } else if (r) {
+            if (recv(s, &arp, sizeof(arp), 0) < 0)
+                break;
+            if (arp.operation == htons(ARPOP_REPLY)
+             && memcmp(arp.tHaddr, from_mac, 6) == 0
+             && *((uint32_t *) arp.sInaddr) == test_ip
+            ) {
                 rv = 0;
                 break;
             }
         }
-        timeout -= uptime() - prevTime;
-        prevTime = uptime();
-    }
+        timeout -= monotonic_sec() - prevTime;
+    } while (timeout > 0);
+
+ ret:
     close(s);
-    DEBUG(LOG_INFO, "%salid arp replies for this address", rv ? "No v" : "V");
+    DEBUG("%srp reply received for this address", rv ? "No a" : "A");
     return rv;
 }