mirror of
https://github.com/nmap/nmap.git
synced 2025-12-23 07:59:03 +00:00
Rename readip_pcap -> readipv4_pcap and readip46_pcap to readip_pcap.
We should have the multiprotocol version be the main version, with IPv4-only code being a noted exception. Also these functions are almost the same so one can call the other.
This commit is contained in:
david
219
tcpip.cc
219
tcpip.cc
@@ -1458,220 +1458,25 @@ static bool validatepkt(u8 *ipc, unsigned *len) {
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linknfo->header will be filled with the appropriate values. */
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/* Specifying true for validate will enable validity checks against the
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received IP packet. See validatepkt() for a list of checks. */
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char *readip_pcap(pcap_t *pd, unsigned int *len, long to_usec,
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struct timeval *rcvdtime, struct link_header *linknfo,
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bool validate) {
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unsigned int offset = 0;
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struct pcap_pkthdr head;
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char *p;
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int datalink;
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int timedout = 0;
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struct timeval tv_start, tv_end;
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static char *alignedbuf = NULL;
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static unsigned int alignedbufsz = 0;
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static int warning = 0;
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char *readipv4_pcap(pcap_t *pd, unsigned int *len, long to_usec,
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struct timeval *rcvdtime, struct link_header *linknfo,
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bool validate) {
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char *buf;
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if (linknfo) {
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memset(linknfo, 0, sizeof(*linknfo));
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}
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buf = readip_pcap(pd, len, to_usec, rcvdtime, linknfo, validate);
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if (buf != NULL) {
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struct ip *ip;
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if (!pd)
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fatal("NULL packet device passed to %s", __func__);
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if (to_usec < 0) {
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if (!warning) {
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warning = 1;
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error("WARNING: Negative timeout value (%lu) passed to %s() -- using 0", to_usec, __func__);
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}
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to_usec = 0;
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}
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/* New packet capture device, need to recompute offset */
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if ((datalink = pcap_datalink(pd)) < 0)
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fatal("Cannot obtain datalink information: %s", pcap_geterr(pd));
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/* NOTE: IF A NEW OFFSET EVER EXCEEDS THE CURRENT MAX (24), ADJUST
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MAX_LINK_HEADERSZ in tcpip.h */
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switch (datalink) {
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case DLT_EN10MB:
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offset = 14;
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break;
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case DLT_IEEE802:
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offset = 22;
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break;
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#ifdef __amigaos__
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case DLT_MIAMI:
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offset = 16;
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break;
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#endif
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#ifdef DLT_LOOP
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case DLT_LOOP:
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#endif
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case DLT_NULL:
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offset = 4;
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break;
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case DLT_SLIP:
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#ifdef DLT_SLIP_BSDOS
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case DLT_SLIP_BSDOS:
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#endif
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#if (FREEBSD || OPENBSD || NETBSD || BSDI || MACOSX)
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offset = 16;
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#else
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offset = 24; /* Anyone use this??? */
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#endif
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break;
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case DLT_PPP:
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#ifdef DLT_PPP_BSDOS
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case DLT_PPP_BSDOS:
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#endif
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#ifdef DLT_PPP_SERIAL
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case DLT_PPP_SERIAL:
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#endif
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#ifdef DLT_PPP_ETHER
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case DLT_PPP_ETHER:
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#endif
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#if (FREEBSD || OPENBSD || NETBSD || BSDI || MACOSX)
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offset = 4;
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#else
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#ifdef SOLARIS
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offset = 8;
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#else
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offset = 24; /* Anyone use this? */
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#endif /* ifdef solaris */
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#endif /* if freebsd || openbsd || netbsd || bsdi */
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break;
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case DLT_RAW:
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offset = 0;
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break;
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case DLT_FDDI:
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offset = 21;
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break;
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#ifdef DLT_ENC
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case DLT_ENC:
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offset = 12;
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break;
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#endif /* DLT_ENC */
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#ifdef DLT_LINUX_SLL
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case DLT_LINUX_SLL:
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offset = 16;
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break;
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#endif
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default:
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p = (char *) pcap_next(pd, &head);
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if (head.caplen == 0) {
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/* Lets sleep a brief time and try again to increase the chance of seeing
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a real packet ... */
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usleep(500000);
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p = (char *) pcap_next(pd, &head);
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}
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if (head.caplen > 100000) {
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fatal("FATAL: %s: bogus caplen from libpcap (%d) on interface type %d", __func__, head.caplen, datalink);
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}
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error("FATAL: Unknown datalink type (%d). Caplen: %d; Packet:", datalink, head.caplen);
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nmap_hexdump((unsigned char *) p, head.caplen);
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exit(1);
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}
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if (to_usec > 0) {
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gettimeofday(&tv_start, NULL);
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}
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do {
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#ifdef WIN32
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long to_left;
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if (to_usec > 0) {
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gettimeofday(&tv_end, NULL);
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to_left = MAX(1, (to_usec - TIMEVAL_SUBTRACT(tv_end, tv_start)) / 1000);
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} else {
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to_left = 1;
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}
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// Set the timeout (BUGBUG: this is cheating)
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PacketSetReadTimeout(pd->adapter, to_left);
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#endif
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p = NULL;
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if (pcap_select(pd, to_usec) == 0)
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timedout = 1;
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else
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p = (char *) pcap_next(pd, &head);
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if (p) {
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if (head.caplen <= offset) {
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*len = 0;
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return NULL;
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}
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if (offset && linknfo) {
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linknfo->datalinktype = datalink;
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linknfo->headerlen = offset;
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assert(offset < MAX_LINK_HEADERSZ);
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memcpy(linknfo->header, p, MIN(sizeof(linknfo->header), offset));
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}
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p += offset;
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}
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if (!p) {
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/* Should we timeout? */
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if (to_usec == 0) {
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timedout = 1;
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} else if (to_usec > 0) {
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gettimeofday(&tv_end, NULL);
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if (TIMEVAL_SUBTRACT(tv_end, tv_start) >= to_usec) {
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timedout = 1;
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}
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}
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}
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} while (!timedout && (!p));
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if (timedout) {
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*len = 0;
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return NULL;
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}
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*len = head.caplen - offset;
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if (*len > alignedbufsz) {
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alignedbuf = (char *) safe_realloc(alignedbuf, *len);
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alignedbufsz = *len;
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}
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memcpy(alignedbuf, p, *len);
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if (validate) {
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const struct ip *ip = (struct ip *) alignedbuf;
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/* Let's see if this packet passes inspection.. */
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if (!validatepkt((u8 *) alignedbuf, len) || ip->ip_v != 4) {
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*len = 0;
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ip = (struct ip *) buf;
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if (*len < 1 || ip->ip_v != 4)
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return NULL;
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}
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}
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// printf("Just got a packet at %li,%li\n", head.ts.tv_sec, head.ts.tv_usec);
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if (rcvdtime) {
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// FIXME: I eventually need to figure out why Windows head.ts time is sometimes BEFORE the time I
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// sent the packet (which is according to gettimeofday() in nbase). For now, I will sadly have to
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// use gettimeofday() for Windows in this case
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// Actually I now allow .05 discrepancy. So maybe this isn't needed. I'll comment out for now.
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// Nope: it is still needed at least for Windows. Sometimes the time from he pcap header is a
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// COUPLE SECONDS before the gettimeofday() results :(.
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#if defined(WIN32) || defined(__amigaos__)
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gettimeofday(&tv_end, NULL);
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*rcvdtime = tv_end;
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#else
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rcvdtime->tv_sec = head.ts.tv_sec;
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rcvdtime->tv_usec = head.ts.tv_usec;
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assert(head.ts.tv_sec);
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#endif
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}
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if (rcvdtime)
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PacketTrace::trace(PacketTrace::RCVD, (u8 *) alignedbuf, *len,
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rcvdtime);
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else
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PacketTrace::trace(PacketTrace::RCVD, (u8 *) alignedbuf, *len);
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return alignedbuf;
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return buf;
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}
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char *readip46_pcap(pcap_t *pd, unsigned int *len, long to_usec,
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struct timeval *rcvdtime, struct link_header *linknfo, bool validate) {
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char *readip_pcap(pcap_t *pd, unsigned int *len, long to_usec,
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struct timeval *rcvdtime, struct link_header *linknfo, bool validate) {
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unsigned int offset = 0;
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struct pcap_pkthdr head;
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char *p;
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