pcap-libdlpi.c

/*
 * Copyright (c) 1993, 1994, 1995, 1996, 1997
 *	The Regents of the University of California.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that: (1) source code distributions
 * retain the above copyright notice and this paragraph in its entirety, (2)
 * distributions including binary code include the above copyright notice and
 * this paragraph in its entirety in the documentation or other materials
 * provided with the distribution, and (3) all advertising materials mentioning
 * features or use of this software display the following acknowledgement:
 * ``This product includes software developed by the University of California,
 * Lawrence Berkeley Laboratory and its contributors.'' Neither the name of
 * the University nor the names of its contributors may be used to endorse
 * or promote products derived from this software without specific prior
 * written permission.
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED
 * WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
 *
 * This code contributed by Sagun Shakya (sagun.shakya@sun.com)
 */
/*
 * Packet capture routines for DLPI using libdlpi under SunOS 5.11.
 */

#include <config.h>

#include <sys/types.h>
#include <sys/time.h>
#include <sys/bufmod.h>
#include <sys/stream.h>
#include <libdlpi.h>
#include <errno.h>
#include <memory.h>
#include <stropts.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include "pcap-int.h"
#include "dlpisubs.h"

/* Forwards. */
static int dlpromiscon(pcap_t *, bpf_u_int32);
static int pcap_read_libdlpi(pcap_t *, int, pcap_handler, u_char *);
static int pcap_inject_libdlpi(pcap_t *, const void *, int);
static void pcap_libdlpi_err(const char *, const char *, int, char *);
static void pcap_cleanup_libdlpi(pcap_t *);

/*
 * list_interfaces() will list all the network links that are
 * available on a system.
 */
static boolean_t list_interfaces(const char *, void *);

typedef struct linknamelist {
	char	linkname[DLPI_LINKNAME_MAX];
	struct linknamelist *lnl_next;
} linknamelist_t;

typedef struct linkwalk {
	linknamelist_t	*lw_list;
	int		lw_err;
} linkwalk_t;

/*
 * The caller of this function should free the memory allocated
 * for each linknamelist_t "entry" allocated.
 */
static boolean_t
list_interfaces(const char *linkname, void *arg)
{
	linkwalk_t	*lwp = arg;
	linknamelist_t	*entry;

	if ((entry = calloc(1, sizeof(linknamelist_t))) == NULL) {
		lwp->lw_err = ENOMEM;
		return (B_TRUE);
	}
	(void) pcapint_strlcpy(entry->linkname, linkname, DLPI_LINKNAME_MAX);

	if (lwp->lw_list == NULL) {
		lwp->lw_list = entry;
	} else {
		entry->lnl_next = lwp->lw_list;
		lwp->lw_list = entry;
	}

	return (B_FALSE);
}

static int
pcap_activate_libdlpi(pcap_t *p)
{
	struct pcap_dlpi *pd = p->priv;
	int status = 0;
	int retv;
	dlpi_handle_t dh;
	dlpi_info_t dlinfo;

	/*
	 * Enable Solaris raw and passive DLPI extensions;
	 * dlpi_open() will not fail if the underlying link does not support
	 * passive mode. See dlpi(7P) for details.
	 */
	retv = dlpi_open(p->opt.device, &dh, DLPI_RAW|DLPI_PASSIVE);
	if (retv != DLPI_SUCCESS) {
		if (retv == DLPI_ELINKNAMEINVAL) {
			/*
			 * The interface name is not syntactiacally
			 * valid, and thus doesn't correspond to
			 * an interface.
			 *
			 * There's nothing more to say, so clear the
			 * error message.
			 */
			status = PCAP_ERROR_NO_SUCH_DEVICE;
			p->errbuf[0] = '\0';
		} else if (retv == DLPI_ENOLINK) {
			/*
			 * The interface name is syntactically valid,
			 * but we don't have a DLPI device that
			 * would be used for that interface.
			 */
			status = handle_nonexistent_dlpi_device(p->opt.device,
			    p->errbuf);
		} else if (retv == DL_SYSERR &&
		    (errno == EPERM || errno == EACCES)) {
			/*
			 * We got EPERM or EACCES trying to open the
			 * DLPI device, so we know it exists.
			 */
			status = PCAP_ERROR_PERM_DENIED;
			snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
			    "Attempt to open DLPI device failed with %s - root privilege may be required",
			    (errno == EPERM) ? "EPERM" : "EACCES");
		} else {
			/*
			 * pcap_libdlpi_err() calls dlpi_strerror(),
			 * which handles DL_SYSERR.
			 *
			 * XXX - does DLPI_ERAWNOTSUP mean that the
			 * interface exists and supports DLPI but,
			 * as it doesn't support raw mode, it
			 * doesn't support packet capture?
			 *
			 * XXX - what does DLPI_EBADLINK mean?
			 */
			status = PCAP_ERROR;
			pcap_libdlpi_err(p->opt.device, "dlpi_open", retv,
			    p->errbuf);
		}
		return (status);
	}
	pd->dlpi_hd = dh;

	if (p->opt.rfmon) {
		/*
		 * This device exists, but we don't support monitor mode
		 * on any platforms that support DLPI.
		 */
		status = PCAP_ERROR_RFMON_NOTSUP;
		goto bad;
	}

	/* Bind with DLPI_ANY_SAP. */
	if ((retv = dlpi_bind(pd->dlpi_hd, DLPI_ANY_SAP, 0)) != DLPI_SUCCESS) {
		status = PCAP_ERROR;
		pcap_libdlpi_err(p->opt.device, "dlpi_bind", retv, p->errbuf);
		goto bad;
	}

	/*
	 * Turn a negative snapshot value (invalid), a snapshot value of
	 * 0 (unspecified), or a value bigger than the normal maximum
	 * value, into the maximum allowed value.
	 *
	 * If some application really *needs* a bigger snapshot
	 * length, we should just increase MAXIMUM_SNAPLEN.
	 */
	if (p->snapshot <= 0 || p->snapshot > MAXIMUM_SNAPLEN)
		p->snapshot = MAXIMUM_SNAPLEN;

	/* Enable promiscuous mode. */
	if (p->opt.promisc) {
		retv = dlpromiscon(p, DL_PROMISC_PHYS);
		if (retv < 0) {
			/*
			 * "You don't have permission to capture on
			 * this device" and "you don't have permission
			 * to capture in promiscuous mode on this
			 * device" are different; let the user know,
			 * so if they can't get permission to
			 * capture in promiscuous mode, they can at
			 * least try to capture in non-promiscuous
			 * mode.
			 *
			 * XXX - you might have to capture in
			 * promiscuous mode to see outgoing packets.
			 */
			if (retv == PCAP_ERROR_PERM_DENIED)
				status = PCAP_ERROR_PROMISC_PERM_DENIED;
			else
				status = retv;
			goto bad;
		}
	} else {
		/* Try to enable multicast. */
		retv = dlpromiscon(p, DL_PROMISC_MULTI);
		if (retv < 0) {
			status = retv;
			goto bad;
		}
	}

	/* Try to enable SAP promiscuity. */
	retv = dlpromiscon(p, DL_PROMISC_SAP);
	if (retv < 0) {
		/*
		 * Not fatal, since the DL_PROMISC_PHYS mode worked.
		 * Report it as a warning, however.
		 */
		if (p->opt.promisc)
			status = PCAP_WARNING;
		else {
			status = retv;
			goto bad;
		}
	}

	/* Determine link type.  */
	if ((retv = dlpi_info(pd->dlpi_hd, &dlinfo, 0)) != DLPI_SUCCESS) {
		status = PCAP_ERROR;
		pcap_libdlpi_err(p->opt.device, "dlpi_info", retv, p->errbuf);
		goto bad;
	}

	if (pcap_process_mactype(p, dlinfo.di_mactype) != 0) {
		status = PCAP_ERROR;
		goto bad;
	}

	p->fd = dlpi_fd(pd->dlpi_hd);

	/* Push and configure bufmod. */
	if (pcap_conf_bufmod(p, p->snapshot) != 0) {
		status = PCAP_ERROR;
		goto bad;
	}

	/*
	 * Flush the read side.
	 */
	if (ioctl(p->fd, I_FLUSH, FLUSHR) != 0) {
		status = PCAP_ERROR;
		pcapint_fmt_errmsg_for_errno(p->errbuf, PCAP_ERRBUF_SIZE,
		    errno, "FLUSHR");
		goto bad;
	}

	/* Allocate data buffer. */
	if (pcap_alloc_databuf(p) != 0) {
		status = PCAP_ERROR;
		goto bad;
	}

	/*
	 * "p->fd" is a FD for a STREAMS device, so "select()" and
	 * "poll()" should work on it.
	 */
	p->selectable_fd = p->fd;

	p->read_op = pcap_read_libdlpi;
	p->inject_op = pcap_inject_libdlpi;
	p->setfilter_op = pcapint_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 = pcapint_getnonblock_fd;
	p->setnonblock_op = pcapint_setnonblock_fd;
	p->stats_op = pcap_stats_dlpi;
	p->cleanup_op = pcap_cleanup_libdlpi;

	return (status);
bad:
	pcap_cleanup_libdlpi(p);
	return (status);
}

#define STRINGIFY(n)	#n

static int
dlpromiscon(pcap_t *p, bpf_u_int32 level)
{
	struct pcap_dlpi *pd = p->priv;
	int retv;
	int err;

	retv = dlpi_promiscon(pd->dlpi_hd, level);
	if (retv != DLPI_SUCCESS) {
		if (retv == DL_SYSERR &&
		    (errno == EPERM || errno == EACCES)) {
			if (level == DL_PROMISC_PHYS) {
				err = PCAP_ERROR_PROMISC_PERM_DENIED;
				snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
				    "Attempt to set promiscuous mode failed with %s - root privilege may be required",
				    (errno == EPERM) ? "EPERM" : "EACCES");
			} else {
				err = PCAP_ERROR_PERM_DENIED;
				snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
				    "Attempt to set %s mode failed with %s - root privilege may be required",
				    (level == DL_PROMISC_MULTI) ? "multicast" : "SAP promiscuous",
				    (errno == EPERM) ? "EPERM" : "EACCES");
			}
		} else {
			err = PCAP_ERROR;
			pcap_libdlpi_err(p->opt.device,
			    "dlpi_promiscon" STRINGIFY(level),
			    retv, p->errbuf);
		}
		return (err);
	}
	return (0);
}

/*
 * Presumably everything returned by dlpi_walk() is a DLPI device,
 * so there's no work to be done here to check whether name refers
 * to a DLPI device.
 */
static int
is_dlpi_interface(const char *name _U_)
{
	return (1);
}

static int
get_if_flags(const char *name _U_, bpf_u_int32 *flags _U_, char *errbuf _U_)
{
	/*
	 * Nothing we can do other than mark loopback devices as "the
	 * connected/disconnected status doesn't apply".
	 *
	 * XXX - on Solaris, can we do what the dladm command does,
	 * i.e. get a connected/disconnected indication from a kstat?
	 * (Note that you can also get the link speed, and possibly
	 * other information, from a kstat as well.)
	 */
	if (*flags & PCAP_IF_LOOPBACK) {
		/*
		 * Loopback devices aren't wireless, and "connected"/
		 * "disconnected" doesn't apply to them.
		 */
		*flags |= PCAP_IF_CONNECTION_STATUS_NOT_APPLICABLE;
		return (0);
	}
	return (0);
}

/*
 * In Solaris, the "standard" mechanism" i.e SIOCGLIFCONF will only find
 * network links that are plumbed and are up. dlpi_walk(3DLPI) will find
 * additional network links present in the system.
 */
int
pcapint_platform_finddevs(pcap_if_list_t *devlistp, char *errbuf)
{
	int retv = 0;

	linknamelist_t	*entry, *next;
	linkwalk_t	lw = {NULL, 0};
	int		save_errno;

	/*
	 * Get the list of regular interfaces first.
	 */
	if (pcapint_findalldevs_interfaces(devlistp, errbuf,
	    is_dlpi_interface, get_if_flags) == -1)
		return (-1);	/* failure */

	/* dlpi_walk() for loopback will be added here. */

	/*
	 * Find all DLPI devices in the current zone.
	 *
	 * XXX - will pcapint_findalldevs_interfaces() find any devices
	 * outside the current zone?  If not, the only reason to call
	 * it would be to get the interface addresses.
	 */
	dlpi_walk(list_interfaces, &lw, 0);

	if (lw.lw_err != 0) {
		pcapint_fmt_errmsg_for_errno(errbuf, PCAP_ERRBUF_SIZE,
		    lw.lw_err, "dlpi_walk");
		retv = -1;
		goto done;
	}

	/* Add linkname if it does not exist on the list. */
	for (entry = lw.lw_list; entry != NULL; entry = entry->lnl_next) {
		/*
		 * If it isn't already in the list of devices, try to
		 * add it.
		 */
		if (pcapint_find_or_add_dev(devlistp, entry->linkname, 0, get_if_flags,
		    NULL, errbuf) == NULL)
			retv = -1;
	}
done:
	save_errno = errno;
	for (entry = lw.lw_list; entry != NULL; entry = next) {
		next = entry->lnl_next;
		free(entry);
	}
	errno = save_errno;

	return (retv);
}

/*
 * Read data received on DLPI handle. Returns -2 if told to terminate, else
 * returns the number of packets read.
 */
static int
pcap_read_libdlpi(pcap_t *p, int count, pcap_handler callback, u_char *user)
{
	struct pcap_dlpi *pd = p->priv;
	int len;
	u_char *bufp;
	size_t msglen;
	int retv;

	len = p->cc;
	if (len != 0) {
		bufp = p->bp;
		goto process_pkts;
	}
	do {
		/* Has "pcap_breakloop()" been called? */
		if (p->break_loop) {
			/*
			 * Yes - clear the flag that indicates that it has,
			 * and return -2 to indicate that we were told to
			 * break out of the loop.
			 */
			p->break_loop = 0;
			return (-2);
		}

		msglen = p->bufsize;
		bufp = p->buffer + p->offset;

		retv = dlpi_recv(pd->dlpi_hd, NULL, NULL, bufp,
		    &msglen, -1, NULL);
		if (retv != DLPI_SUCCESS) {
			/*
			 * This is most likely a call to terminate out of the
			 * loop. So, do not return an error message, instead
			 * check if "pcap_breakloop()" has been called above.
			 */
			if (retv == DL_SYSERR && errno == EINTR) {
				len = 0;
				continue;
			}
			pcap_libdlpi_err(dlpi_linkname(pd->dlpi_hd),
			    "dlpi_recv", retv, p->errbuf);
			return (-1);
		}
		len = msglen;
	} while (len == 0);

process_pkts:
	return (pcap_process_pkts(p, callback, user, count, bufp, len));
}

static int
pcap_inject_libdlpi(pcap_t *p, const void *buf, int size)
{
	struct pcap_dlpi *pd = p->priv;
	int retv;

	retv = dlpi_send(pd->dlpi_hd, NULL, 0, buf, size, NULL);
	if (retv != DLPI_SUCCESS) {
		pcap_libdlpi_err(dlpi_linkname(pd->dlpi_hd), "dlpi_send", retv,
		    p->errbuf);
		return (-1);
	}
	/*
	 * dlpi_send(3DLPI) does not provide a way to return the number of
	 * bytes sent on the wire. Based on the fact that DLPI_SUCCESS was
	 * returned we are assuming 'size' bytes were sent.
	 */
	return (size);
}

/*
 * Close dlpi handle.
 */
static void
pcap_cleanup_libdlpi(pcap_t *p)
{
	struct pcap_dlpi *pd = p->priv;

	if (pd->dlpi_hd != NULL) {
		dlpi_close(pd->dlpi_hd);
		pd->dlpi_hd = NULL;
		p->fd = -1;
	}
	pcapint_cleanup_live_common(p);
}

/*
 * Write error message to buffer.
 */
static void
pcap_libdlpi_err(const char *linkname, const char *func, int err, char *errbuf)
{
	snprintf(errbuf, PCAP_ERRBUF_SIZE, "%s failed on %s: %s",
	    func, linkname, dlpi_strerror(err));
}

pcap_t *
pcapint_create_interface(const char *device _U_, char *ebuf)
{
	pcap_t *p;

	p = PCAP_CREATE_COMMON(ebuf, struct pcap_dlpi);
	if (p == NULL)
		return (NULL);

	p->activate_op = pcap_activate_libdlpi;
	return (p);
}

/*
 * Libpcap version string.
 */
const char *
pcap_lib_version(void)
{
	return (PCAP_VERSION_STRING);
}