pcap-dlpi.c

Windows XP下的抓包程序实现

	p->selectable_fd = p->fd;

	p->read_op = pcap_read_dlpi;
	p->inject_op = pcap_inject_dlpi;
	p->setfilter_op = install_bpf_program;	/* no kernel filtering */
	p->setdirection_op = NULL;	/* Not implemented.*/
	p->set_datalink_op = NULL;	/* can't change data link type */
	p->getnonblock_op = pcap_getnonblock_fd;
	p->setnonblock_op = pcap_setnonblock_fd;
	p->stats_op = pcap_stats_dlpi;
	p->close_op = pcap_close_dlpi;

	return (p);
bad:
	if (p->fd >= 0)
		close(p->fd);
	if (p->send_fd >= 0)
		close(p->send_fd);
	/*
	 * Get rid of any link-layer type list we allocated.
	 */
	if (p->dlt_list != NULL)
		free(p->dlt_list);
	free(p);
	return (NULL);
}

/*
 * Split a device name into a device type name and a unit number;
 * return the a pointer to the beginning of the unit number, which
 * is the end of the device type name, and set "*unitp" to the unit
 * number.
 *
 * Returns NULL on error, and fills "ebuf" with an error message.
 */
static char *
split_dname(char *device, int *unitp, char *ebuf)
{
	char *cp;
	char *eos;
	long unit;

	/*
	 * Look for a number at the end of the device name string.
	 */
	cp = device + strlen(device) - 1;
	if (*cp < '0' || *cp > '9') {
		snprintf(ebuf, PCAP_ERRBUF_SIZE, "%s missing unit number",
		    device);
		return (NULL);
	}

	/* Digits at end of string are unit number */
	while (cp-1 >= device && *(cp-1) >= '0' && *(cp-1) <= '9')
		cp--;

	errno = 0;
	unit = strtol(cp, &eos, 10);
	if (*eos != '\0') {
		snprintf(ebuf, PCAP_ERRBUF_SIZE, "%s bad unit number", device);
		return (NULL);
	}
	if (errno == ERANGE || unit > INT_MAX) {
		snprintf(ebuf, PCAP_ERRBUF_SIZE, "%s unit number too large",
		    device);
		return (NULL);
	}
	if (unit < 0) {
		snprintf(ebuf, PCAP_ERRBUF_SIZE, "%s unit number is negative",
		    device);
		return (NULL);
	}
	*unitp = (int)unit;
	return (cp);
}

static int
dl_doattach(int fd, int ppa, char *ebuf)
{
	bpf_u_int32 buf[MAXDLBUF];

	if (dlattachreq(fd, ppa, ebuf) < 0 ||
	    dlokack(fd, "attach", (char *)buf, ebuf) < 0)
		return (-1);
	return (0);
}

#ifdef DL_HP_RAWDLS
static int
dl_dohpuxbind(int fd, char *ebuf)
{
	int hpsap;
	int uerror;
	bpf_u_int32 buf[MAXDLBUF];

	/*
	 * XXX - we start at 22 because we used to use only 22, but
	 * that was just because that was the value used in some
	 * sample code from HP.  With what value *should* we start?
	 * Does it matter, given that we're enabling SAP promiscuity
	 * on the input FD?
	 */
	hpsap = 22;
	for (;;) {
		if (dlbindreq(fd, hpsap, ebuf) < 0)
			return (-1);
		if (dlbindack(fd, (char *)buf, ebuf, &uerror) >= 0)
			break;
		/*
		 * For any error other than a UNIX EBUSY, give up.
		 */
		if (uerror != EBUSY) {
			/*
			 * dlbindack() has already filled in ebuf for
			 * this error.
			 */
			return (-1);
		}

		/*
		 * For EBUSY, try the next SAP value; that means that
		 * somebody else is using that SAP.  Clear ebuf so
		 * that application doesn't report the "Device busy"
		 * error as a warning.
		 */
		*ebuf = '\0';
		hpsap++;
		if (hpsap > 100) {
			strlcpy(ebuf,
			    "All SAPs from 22 through 100 are in use",
			    PCAP_ERRBUF_SIZE);
			return (-1);
		}
	}
	return (0);
}
#endif

int
pcap_platform_finddevs(pcap_if_t **alldevsp, char *errbuf)
{
#ifdef HAVE_SOLARIS
	int fd;
	union {
		u_int nunits;
		char pad[516];	/* XXX - must be at least 513; is 516
				   in "atmgetunits" */
	} buf;
	char baname[2+1+1];
	u_int i;

	/*
	 * We may have to do special magic to get ATM devices.
	 */
	if ((fd = open("/dev/ba", O_RDWR)) < 0) {
		/*
		 * We couldn't open the "ba" device.
		 * For now, just give up; perhaps we should
		 * return an error if the problem is neither
		 * a "that device doesn't exist" error (ENOENT,
		 * ENXIO, etc.) or a "you're not allowed to do
		 * that" error (EPERM, EACCES).
		 */
		return (0);
	}

	if (strioctl(fd, A_GET_UNITS, sizeof(buf), (char *)&buf) < 0) {
		snprintf(errbuf, PCAP_ERRBUF_SIZE, "A_GET_UNITS: %s",
		    pcap_strerror(errno));
		return (-1);
	}
	for (i = 0; i < buf.nunits; i++) {
		snprintf(baname, sizeof baname, "ba%u", i);
		if (pcap_add_if(alldevsp, baname, 0, NULL, errbuf) < 0)
			return (-1);
	}
#endif

	return (0);
}

static int
send_request(int fd, char *ptr, int len, char *what, char *ebuf)
{
	struct	strbuf	ctl;
	int	flags;

	ctl.maxlen = 0;
	ctl.len = len;
	ctl.buf = ptr;

	flags = 0;
	if (putmsg(fd, &ctl, (struct strbuf *) NULL, flags) < 0) {
		snprintf(ebuf, PCAP_ERRBUF_SIZE,
		    "send_request: putmsg \"%s\": %s",
		    what, pcap_strerror(errno));
		return (-1);
	}
	return (0);
}

static int
recv_ack(int fd, int size, const char *what, char *bufp, char *ebuf, int *uerror)
{
	union	DL_primitives	*dlp;
	struct	strbuf	ctl;
	int	flags;

	/*
	 * Clear out "*uerror", so it's only set for DL_ERROR_ACK/DL_SYSERR,
	 * making that the only place where EBUSY is treated specially.
	 */
	if (uerror != NULL)
		*uerror = 0;

	ctl.maxlen = MAXDLBUF;
	ctl.len = 0;
	ctl.buf = bufp;

	flags = 0;
	if (getmsg(fd, &ctl, (struct strbuf*)NULL, &flags) < 0) {
		snprintf(ebuf, PCAP_ERRBUF_SIZE, "recv_ack: %s getmsg: %s",
		    what, pcap_strerror(errno));
		return (-1);
	}

	dlp = (union DL_primitives *) ctl.buf;
	switch (dlp->dl_primitive) {

	case DL_INFO_ACK:
	case DL_BIND_ACK:
	case DL_OK_ACK:
#ifdef DL_HP_PPA_ACK
	case DL_HP_PPA_ACK:
#endif
		/* These are OK */
		break;

	case DL_ERROR_ACK:
		switch (dlp->error_ack.dl_errno) {

		case DL_SYSERR:
			if (uerror != NULL)
				*uerror = dlp->error_ack.dl_unix_errno;
			snprintf(ebuf, PCAP_ERRBUF_SIZE,
			    "recv_ack: %s: UNIX error - %s",
			    what, pcap_strerror(dlp->error_ack.dl_unix_errno));
			break;

		default:
			snprintf(ebuf, PCAP_ERRBUF_SIZE, "recv_ack: %s: %s",
			    what, dlstrerror(dlp->error_ack.dl_errno));
			break;
		}
		return (-1);

	default:
		snprintf(ebuf, PCAP_ERRBUF_SIZE,
		    "recv_ack: %s: Unexpected primitive ack %s",
		    what, dlprim(dlp->dl_primitive));
		return (-1);
	}

	if (ctl.len < size) {
		snprintf(ebuf, PCAP_ERRBUF_SIZE,
		    "recv_ack: %s: Ack too small (%d < %d)",
		    what, ctl.len, size);
		return (-1);
	}
	return (ctl.len);
}

static char *
dlstrerror(bpf_u_int32 dl_errno)
{
	static char errstring[6+2+8+1];

	switch (dl_errno) {

	case DL_ACCESS:
		return ("Improper permissions for request");

	case DL_BADADDR:
		return ("DLSAP addr in improper format or invalid");

	case DL_BADCORR:
		return ("Seq number not from outstand DL_CONN_IND");

	case DL_BADDATA:
		return ("User data exceeded provider limit");

	case DL_BADPPA:
#ifdef HAVE_DEV_DLPI
		/*
		 * With a single "/dev/dlpi" device used for all
		 * DLPI providers, PPAs have nothing to do with
		 * unit numbers.
		 */
		return ("Specified PPA was invalid");
#else
		/*
		 * We have separate devices for separate devices;
		 * the PPA is just the unit number.
		 */
		return ("Specified PPA (device unit) was invalid");
#endif

	case DL_BADPRIM:
		return ("Primitive received not known by provider");

	case DL_BADQOSPARAM:
		return ("QOS parameters contained invalid values");

	case DL_BADQOSTYPE:
		return ("QOS structure type is unknown/unsupported");

	case DL_BADSAP:
		return ("Bad LSAP selector");

	case DL_BADTOKEN:
		return ("Token used not an active stream");

	case DL_BOUND:
		return ("Attempted second bind with dl_max_conind");

	case DL_INITFAILED:
		return ("Physical link initialization failed");

	case DL_NOADDR:
		return ("Provider couldn't allocate alternate address");

	case DL_NOTINIT:
		return ("Physical link not initialized");

	case DL_OUTSTATE:
		return ("Primitive issued in improper state");

	case DL_SYSERR:
		return ("UNIX system error occurred");

	case DL_UNSUPPORTED:
		return ("Requested service not supplied by provider");

	case DL_UNDELIVERABLE:
		return ("Previous data unit could not be delivered");

	case DL_NOTSUPPORTED:
		return ("Primitive is known but not supported");

	case DL_TOOMANY:
		return ("Limit exceeded");

	case DL_NOTENAB:
		return ("Promiscuous mode not enabled");

	case DL_BUSY:
		return ("Other streams for PPA in post-attached");

	case DL_NOAUTO:
		return ("Automatic handling XID&TEST not supported");

	case DL_NOXIDAUTO:
		return ("Automatic handling of XID not supported");

	case DL_NOTESTAUTO:
		return ("Automatic handling of TEST not supported");

	case DL_XIDAUTO:
		return ("Automatic handling of XID response");

	case DL_TESTAUTO:
		return ("Automatic handling of TEST response");

	case DL_PENDING:
		return ("Pending outstanding connect indications");

	default:
		sprintf(errstring, "Error %02x", dl_errno);
		return (errstring);
	}
}

static char *
dlprim(bpf_u_int32 prim)
{
	static char primbuf[80];

	switch (prim) {

	case DL_INFO_REQ:
		return ("DL_INFO_REQ");

	case DL_INFO_ACK:
		return ("DL_INFO_ACK");

	case DL_ATTACH_REQ:
		return ("DL_ATTACH_REQ");

	case DL_DETACH_REQ:
		return ("DL_DETACH_REQ");

	case DL_BIND_REQ:
		return ("DL_BIND_REQ");

	case DL_BIND_ACK:
		return ("DL_BIND_ACK");

	case DL_UNBIND_REQ:
		return ("DL_UNBIND_REQ");

	case DL_OK_ACK:
		return ("DL_OK_ACK");

	case DL_ERROR_ACK:
		return ("DL_ERROR_ACK");

	case DL_SUBS_BIND_REQ:
		return ("DL_SUBS_BIND_REQ");

	case DL_SUBS_BIND_ACK:
		return ("DL_SUBS_BIND_ACK");

	case DL_UNITDATA_REQ:
		return ("DL_UNITDATA_REQ");

	case DL_UNITDATA_IND:
		return ("DL_UNITDATA_IND");

	case DL_UDERROR_IND:
		return ("DL_UDERROR_IND");

	case DL_UDQOS_REQ:
		return ("DL_UDQOS_REQ");

	case DL_CONNECT_REQ:
		return ("DL_CONNECT_REQ");

	case DL_CONNECT_IND:
		return ("DL_CONNECT_IND");

	case DL_CONNECT_RES:
		return ("DL_CONNECT_RES");

	case DL_CONNECT_CON:
		return ("DL_CONNECT_CON");

	case DL_TOKEN_REQ:
		return ("DL_TOKEN_REQ");

	case DL_TOKEN_ACK:
		return ("DL_TOKEN_ACK");

	case DL_DISCONNECT_REQ:
		return ("DL_DISCONNECT_REQ");

	case DL_DISCONNECT_IND:
		return ("DL_DISCONNECT_IND");

	case DL_RESET_REQ:
		return ("DL_RESET_REQ");

	case DL_RESET_IND:
		return ("DL_RESET_IND");

	case DL_RESET_RES:
		return ("DL_RESET_RES");

	case DL_RESET_CON:
		return ("DL_RESET_CON");