Adding upstream version 4.2.2.upstream/4.2.2

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 838 insertions, 0 deletions

diff --git a/wiretap/pppdump.c b/wiretap/pppdump.c
new file mode 100644
index 00000000..15eda4fc
--- /dev/null
+++ b/wiretap/pppdump.c
@@ -0,0 +1,838 @@
+/* pppdump.c
+ *
+ * Copyright (c) 2000 by Gilbert Ramirez <gram@alumni.rice.edu>
+ *
+ * SPDX-License-Identifier: GPL-2.0-or-later
+ */
+
+#include "config.h"
+#include "wtap-int.h"
+#include "pppdump.h"
+#include "file_wrappers.h"
+
+#include <stdlib.h>
+#include <errno.h>
+#include <string.h>
+
+#include <wsutil/ws_assert.h>
+
+/*
+pppdump records
+Daniel Thompson (STMicroelectronics) <daniel.thompson@st.com>
+
++------+
+| 0x07 |                              Reset time
++------+------+------+------+
+|  t3  |  t2  |  t1  |  t0  |         t = time_t
++------+------+------+------+
+
++------+
+| 0x06 |                              Time step (short)
++------+
+|  ts  |                              ts = time step (tenths of seconds)
++------+
+
++------+
+| 0x05 |                              Time step (long)
++------+------+------+------+
+| ts3  | ts2  | ts1  | ts0  |         ts = time step (tenths of seconds)
++------+------+------+------+
+
++------+
+| 0x04 |                              Receive deliminator (not seen in practice)
++------+
+
++------+
+| 0x03 |                              Send deliminator (not seen in practice)
++------+
+
++------+
+| 0x02 |                              Received data
++------+------+
+|  n1  |  n0  |                       n = number of bytes following
++------+------+
+|    data     |
+|             |
+
++------+
+| 0x01 |                              Sent data
++------+------+
+|  n1  |  n0  |                       n = number of bytes following
++------+------+
+|    data     |
+|             |
+*/
+
+#define PPPD_SENT_DATA		0x01
+#define PPPD_RECV_DATA		0x02
+#define PPPD_SEND_DELIM		0x03
+#define PPPD_RECV_DELIM		0x04
+#define PPPD_TIME_STEP_LONG	0x05
+#define PPPD_TIME_STEP_SHORT	0x06
+#define PPPD_RESET_TIME		0x07
+
+/* this buffer must be at least (2*PPPD_MTU) + sizeof(ppp_header) +
+ * sizeof(lcp_header) + sizeof(ipcp_header).  PPPD_MTU is *very* rarely
+ * larger than 1500 so this value is fine.
+ *
+ * It's less than WTAP_MAX_PACKET_SIZE_STANDARD, so we don't have to worry about
+ * too-large packets.
+ */
+#define PPPD_BUF_SIZE		8192
+
+typedef enum {
+	DIRECTION_SENT,
+	DIRECTION_RECV
+} direction_enum;
+
+static gboolean pppdump_read(wtap *wth, wtap_rec *rec, Buffer *buf,
+	int *err, gchar **err_info, gint64 *data_offset);
+static gboolean pppdump_seek_read(wtap *wth, gint64 seek_off,
+	wtap_rec *rec, Buffer *buf, int *err, gchar **err_info);
+
+static int pppdump_file_type_subtype = -1;
+
+void register_pppdump(void);
+
+/*
+ * Information saved about a packet, during the initial sequential pass
+ * through the file, to allow us to later re-read it when randomly
+ * reading packets.
+ *
+ * "offset" is the offset in the file of the first data chunk containing data
+ * from that packet; note that it may also contain data from previous
+ * packets.
+ *
+ * "num_bytes_to_skip" is the number of bytes from previous packets in that
+ * first data chunk.
+ *
+ * "dir" is the direction of the packet.
+ */
+typedef struct {
+	gint64		offset;
+	gint64		num_bytes_to_skip;
+	direction_enum	dir;
+} pkt_id;
+
+/*
+ * Information about a packet currently being processed.  There is one of
+ * these for the sent packet being processed and one of these for the
+ * received packet being processed, as we could be in the middle of
+ * processing both a received packet and a sent packet.
+ *
+ * "dir" is the direction of the packet.
+ *
+ * "cnt" is the number of bytes of packet data we've accumulated.
+ *
+ * "esc" is TRUE if the next byte we see is escaped (and thus must be XORed
+ * with 0x20 before saving it), FALSE otherwise.
+ *
+ * "buf" is a buffer containing the packet data we've accumulated.
+ *
+ * "id_offset" is the offset in the file of the first data chunk
+ * containing data from the packet we're processing.
+ *
+ * "sd_offset" is the offset in the file of the first data byte from
+ * the packet we're processing - which isn't necessarily right after
+ * the header of the first data chunk, as we may already have assembled
+ * packets from that chunk.
+ *
+ * "cd_offset" is the offset in the file of the current data chunk we're
+ * processing.
+ */
+typedef struct {
+	direction_enum	dir;
+	int		cnt;
+	gboolean	esc;
+	guint8		buf[PPPD_BUF_SIZE];
+	gint64		id_offset;
+	gint64		sd_offset;
+	gint64		cd_offset;
+} pkt_t;
+
+/*
+ * This keeps state used while processing records.
+ *
+ * "timestamp" is the seconds portion of the current time stamp value,
+ * as updated from PPPD_RESET_TIME, PPPD_TIME_STEP_LONG, and
+ * PPPD_TIME_STEP_SHORT records.  "tenths" is the tenths-of-seconds
+ * portion.
+ *
+ * "spkt" and "rpkt" are "pkt_t" structures for the sent and received
+ * packets we're currently working on.
+ *
+ * "offset" is the current offset in the file.
+ *
+ * "num_bytes" and "pkt" are information saved when we finish accumulating
+ * the data for a packet, if the data chunk we're working on still has more
+ * data in it:
+ *
+ *	"num_bytes" is the number of bytes of additional data remaining
+ *	in the chunk after we've finished accumulating the data for the
+ *	packet.
+ *
+ *	"pkt" is the "pkt_t" for the type of packet the data chunk is for
+ *	(sent or received packet).
+ *
+ * "seek_state" is another state structure used while processing records
+ * when doing a seek-and-read.  (That structure doesn't itself have a
+ * "seek_state" structure.)
+ *
+ * "pids" is a GPtrArray of pointers to "pkt_id" structures for all the
+ * packets we've seen during the initial sequential pass, to allow us to
+ * later retrieve them with random accesses.
+ *
+ * "pkt_cnt" is the number of packets we've seen up to this point in the
+ * sequential pass.
+ */
+typedef struct _pppdump_t {
+	time_t			timestamp;
+	guint			tenths;
+	pkt_t			spkt;
+	pkt_t			rpkt;
+	gint64			offset;
+	int			num_bytes;
+	pkt_t			*pkt;
+	struct _pppdump_t	*seek_state;
+	GPtrArray		*pids;
+	guint			pkt_cnt;
+} pppdump_t;
+
+static int
+process_data(pppdump_t *state, FILE_T fh, pkt_t *pkt, int n, guint8 *pd,
+    int *err, gchar **err_info, pkt_id *pid);
+
+static gboolean
+collate(pppdump_t *state, FILE_T fh, int *err, gchar **err_info, guint8 *pd,
+		int *num_bytes, direction_enum *direction, pkt_id *pid,
+		gint64 num_bytes_to_skip);
+
+static void
+pppdump_close(wtap *wth);
+
+static void
+init_state(pppdump_t *state)
+{
+
+	state->num_bytes = 0;
+	state->pkt = NULL;
+
+	state->spkt.dir = DIRECTION_SENT;
+	state->spkt.cnt = 0;
+	state->spkt.esc = FALSE;
+	state->spkt.id_offset = 0;
+	state->spkt.sd_offset = 0;
+	state->spkt.cd_offset = 0;
+
+	state->rpkt.dir = DIRECTION_RECV;
+	state->rpkt.cnt = 0;
+	state->rpkt.esc = FALSE;
+	state->rpkt.id_offset = 0;
+	state->rpkt.sd_offset = 0;
+	state->rpkt.cd_offset = 0;
+
+	state->seek_state = NULL;
+	state->offset = 0x100000; /* to detect errors during development */
+}
+
+
+wtap_open_return_val
+pppdump_open(wtap *wth, int *err, gchar **err_info)
+{
+	guint8		buffer[6];	/* Looking for: 0x07 t3 t2 t1 t0 ID */
+	pppdump_t	*state;
+
+	/* There is no file header, only packet records. Fortunately for us,
+	* timestamp records are separated from packet records, so we should
+	* find an "initial time stamp" (i.e., a "reset time" record, or
+	* record type 0x07) at the beginning of the file. We'll check for
+	* that, plus a valid record following the 0x07 and the four bytes
+	* representing the timestamp.
+	*/
+
+	if (!wtap_read_bytes(wth->fh, buffer, sizeof(buffer),
+	    err, err_info)) {
+		if (*err != WTAP_ERR_SHORT_READ)
+			return WTAP_OPEN_ERROR;
+		return WTAP_OPEN_NOT_MINE;
+	}
+
+	if (buffer[0] == PPPD_RESET_TIME &&
+			(buffer[5] == PPPD_SENT_DATA ||
+			 buffer[5] == PPPD_RECV_DATA ||
+			 buffer[5] == PPPD_TIME_STEP_LONG ||
+			 buffer[5] == PPPD_TIME_STEP_SHORT ||
+			 buffer[5] == PPPD_RESET_TIME)) {
+
+		goto my_file_type;
+	}
+	else {
+		return WTAP_OPEN_NOT_MINE;
+	}
+
+  my_file_type:
+
+	if (file_seek(wth->fh, 5, SEEK_SET, err) == -1)
+		return WTAP_OPEN_ERROR;
+
+	state = g_new(pppdump_t, 1);
+	wth->priv = (void *)state;
+	state->timestamp = pntoh32(&buffer[1]);
+	state->tenths = 0;
+
+	init_state(state);
+
+	state->offset = 5;
+	wth->file_encap = WTAP_ENCAP_PPP_WITH_PHDR;
+	wth->file_type_subtype = pppdump_file_type_subtype;
+
+	wth->snapshot_length = PPPD_BUF_SIZE; /* just guessing */
+	wth->subtype_read = pppdump_read;
+	wth->subtype_seek_read = pppdump_seek_read;
+	wth->subtype_close = pppdump_close;
+	wth->file_tsprec = WTAP_TSPREC_100_MSEC;
+
+	state->seek_state = g_new(pppdump_t,1);
+
+	/* If we have a random stream open, we're going to be reading
+	   the file randomly; set up a GPtrArray of pointers to
+	   information about how to retrieve the data for each packet. */
+	if (wth->random_fh != NULL)
+		state->pids = g_ptr_array_new();
+	else
+		state->pids = NULL;
+	state->pkt_cnt = 0;
+
+	/*
+	 * Add an IDB; we don't know how many interfaces were
+	 * involved, so we just say one interface, about which
+	 * we only know the link-layer type, snapshot length,
+	 * and time stamp resolution.
+	 */
+	wtap_add_generated_idb(wth);
+
+	return WTAP_OPEN_MINE;
+}
+
+/* Set part of the struct wtap_rec. */
+static void
+pppdump_set_phdr(wtap_rec *rec, int num_bytes,
+    direction_enum direction)
+{
+	rec->rec_type = REC_TYPE_PACKET;
+	rec->block = wtap_block_create(WTAP_BLOCK_PACKET);
+	rec->rec_header.packet_header.len = num_bytes;
+	rec->rec_header.packet_header.caplen = num_bytes;
+	rec->rec_header.packet_header.pkt_encap	= WTAP_ENCAP_PPP_WITH_PHDR;
+
+	rec->rec_header.packet_header.pseudo_header.p2p.sent = (direction == DIRECTION_SENT ? TRUE : FALSE);
+}
+
+/* Find the next packet and parse it; called from wtap_read(). */
+static gboolean
+pppdump_read(wtap *wth, wtap_rec *rec, Buffer *buf, int *err, gchar **err_info,
+    gint64 *data_offset)
+{
+	int		num_bytes;
+	direction_enum	direction;
+	pppdump_t	*state;
+	pkt_id		*pid;
+
+	state = (pppdump_t *)wth->priv;
+
+	/* If we have a random stream open, allocate a structure to hold
+	   the information needed to read this packet's data again. */
+	if (wth->random_fh != NULL) {
+		pid = g_new(pkt_id, 1);
+		if (!pid) {
+			*err = errno;	/* assume a malloc failed and set "errno" */
+			return FALSE;
+		}
+		pid->offset = 0;
+	} else
+		pid = NULL;	/* sequential only */
+
+	ws_buffer_assure_space(buf, PPPD_BUF_SIZE);
+	if (!collate(state, wth->fh, err, err_info, ws_buffer_start_ptr(buf),
+	    &num_bytes, &direction, pid, 0)) {
+		g_free(pid);
+		return FALSE;
+	}
+
+	if (pid != NULL)
+		pid->dir = direction;
+
+	if (pid != NULL)
+		g_ptr_array_add(state->pids, pid);
+	/* The user's data_offset is not really an offset, but a packet number. */
+	*data_offset = state->pkt_cnt;
+	state->pkt_cnt++;
+
+	pppdump_set_phdr(rec, num_bytes, direction);
+	rec->presence_flags = WTAP_HAS_TS;
+	rec->ts.secs = state->timestamp;
+	rec->ts.nsecs = state->tenths * 100000000;
+
+	return TRUE;
+}
+
+/* Returns number of bytes copied for record, -1 if failure.
+ *
+ * This is modeled after pppdump.c, the utility to parse pppd log files; it
+ * comes with the ppp distribution.
+ */
+static int
+process_data(pppdump_t *state, FILE_T fh, pkt_t *pkt, int n, guint8 *pd,
+    int *err, gchar **err_info, pkt_id *pid)
+{
+	int	c;
+	int	num_bytes = n;
+	int	num_written;
+
+	for (; num_bytes > 0; --num_bytes) {
+		c = file_getc(fh);
+		if (c == EOF) {
+			*err = file_error(fh, err_info);
+			if (*err == 0) {
+				*err = WTAP_ERR_SHORT_READ;
+			}
+			return -1;
+		}
+		state->offset++;
+		switch (c) {
+			case 0x7e:
+				/*
+				 * Flag Sequence for RFC 1662 HDLC-like
+				 * framing.
+				 *
+				 * As this is a raw trace of octets going
+				 * over the wire, and that might include
+				 * the login sequence, there is no
+				 * guarantee that *only* PPP traffic
+				 * appears in this file, so there is no
+				 * guarantee that the first 0x7e we see is
+				 * a start flag sequence, and therefore we
+				 * cannot safely ignore all characters up
+				 * to the first 0x7e, and therefore we
+				 * might end up with some bogus PPP
+				 * packets.
+				 */
+				if (pkt->cnt > 0) {
+					/*
+					 * We've seen stuff before this,
+					 * so this is the end of a frame.
+					 * Make a frame out of that stuff.
+					 */
+					pkt->esc = FALSE;
+
+					num_written = pkt->cnt;
+					pkt->cnt = 0;
+					if (num_written <= 0) {
+						return 0;
+					}
+
+					if (num_written > PPPD_BUF_SIZE) {
+						*err = WTAP_ERR_BAD_FILE;
+						*err_info = ws_strdup_printf("pppdump: File has %u-byte packet, bigger than maximum of %u",
+						    num_written, PPPD_BUF_SIZE);
+						return -1;
+					}
+
+					memcpy(pd, pkt->buf, num_written);
+
+					/*
+					 * Remember the offset of the
+					 * first record containing data
+					 * for this packet, and how far
+					 * into that record to skip to
+					 * get to the beginning of the
+					 * data for this packet; the number
+					 * of bytes to skip into that record
+					 * is the file offset of the first
+					 * byte of this packet minus the
+					 * file offset of the first byte of
+					 * this record, minus 3 bytes for the
+					 * header of this record (which, if
+					 * we re-read this record, we will
+					 * process, not skip).
+					 */
+					if (pid) {
+						pid->offset = pkt->id_offset;
+						pid->num_bytes_to_skip =
+						    pkt->sd_offset - pkt->id_offset - 3;
+						ws_assert(pid->num_bytes_to_skip >= 0);
+					}
+
+					num_bytes--;
+					if (num_bytes > 0) {
+						/*
+						 * There's more data in this
+						 * record.
+						 * Set the initial data offset
+						 * for the next packet.
+						 */
+						pkt->id_offset = pkt->cd_offset;
+						pkt->sd_offset = state->offset;
+					} else {
+						/*
+						 * There is no more data in
+						 * this record.
+						 * Thus, we don't have the
+						 * initial data offset for
+						 * the next packet.
+						 */
+						pkt->id_offset = 0;
+						pkt->sd_offset = 0;
+					}
+					state->num_bytes = num_bytes;
+					state->pkt = pkt;
+					return num_written;
+				}
+				break;
+
+			case 0x7d:
+				/*
+				 * Control Escape octet for octet-stuffed
+				 * RFC 1662 HDLC-like framing.
+				 */
+				if (!pkt->esc) {
+					/*
+					 * Control Escape not preceded by
+					 * Control Escape; discard it
+					 * but XOR the next octet with
+					 * 0x20.
+					 */
+					pkt->esc = TRUE;
+					break;
+				}
+				/*
+				 * Control Escape preceded by Control Escape;
+				 * treat it as an ordinary character,
+				 * by falling through.
+				 */
+
+			/* FALL THROUGH */
+			default:
+				if (pkt->esc) {
+					/*
+					 * This character was preceded by
+					 * Control Escape, so XOR it with
+					 * 0x20, as per RFC 1662's octet-
+					 * stuffed framing, and clear
+					 * the flag saying that the
+					 * character should be escaped.
+					 */
+					c ^= 0x20;
+					pkt->esc = FALSE;
+				}
+
+				if (pkt->cnt >= PPPD_BUF_SIZE) {
+					*err = WTAP_ERR_BAD_FILE;
+					*err_info = ws_strdup_printf("pppdump: File has %u-byte packet, bigger than maximum of %u",
+					    pkt->cnt - 1, PPPD_BUF_SIZE);
+					return -1;
+				}
+				pkt->buf[pkt->cnt++] = c;
+				break;
+		}
+	}
+
+	/* we could have run out of bytes to read */
+	return 0;
+}
+
+/* Returns TRUE if packet data copied, FALSE if error occurred or EOF (no more records). */
+static gboolean
+collate(pppdump_t* state, FILE_T fh, int *err, gchar **err_info, guint8 *pd,
+		int *num_bytes, direction_enum *direction, pkt_id *pid,
+		gint64 num_bytes_to_skip)
+{
+	int		id;
+	pkt_t		*pkt = NULL;
+	int		byte0, byte1;
+	int		n, num_written = 0;
+	gint64		start_offset;
+	guint32		time_long;
+	guint8		time_short;
+
+	/*
+	 * Process any data left over in the current record when doing
+	 * sequential processing.
+	 */
+	if (state->num_bytes > 0) {
+		ws_assert(num_bytes_to_skip == 0);
+		pkt = state->pkt;
+		num_written = process_data(state, fh, pkt, state->num_bytes,
+		    pd, err, err_info, pid);
+
+		if (num_written < 0) {
+			return FALSE;
+		}
+		else if (num_written > 0) {
+			*num_bytes = num_written;
+			*direction = pkt->dir;
+			return TRUE;
+		}
+		/* if 0 bytes written, keep processing */
+	} else {
+		/*
+		 * We didn't have any data left over, so the packet will
+		 * start at the beginning of a record.
+		 */
+		if (pid)
+			pid->num_bytes_to_skip = 0;
+	}
+
+	/*
+	 * That didn't get all the data for this packet, so process
+	 * subsequent records.
+	 */
+	start_offset = state->offset;
+	while ((id = file_getc(fh)) != EOF) {
+		state->offset++;
+		switch (id) {
+			case PPPD_SENT_DATA:
+			case PPPD_RECV_DATA:
+				pkt = id == PPPD_SENT_DATA ? &state->spkt : &state->rpkt;
+
+				/*
+				 * Save the offset of the beginning of
+				 * the current record.
+				 */
+				pkt->cd_offset = state->offset - 1;
+
+				/*
+				 * Get the length of the record.
+				 */
+				byte0 = file_getc(fh);
+				if (byte0 == EOF)
+					goto done;
+				state->offset++;
+				byte1 = file_getc(fh);
+				if (byte1 == EOF)
+					goto done;
+				state->offset++;
+				n = (byte0 << 8) | byte1;
+
+				if (pkt->id_offset == 0) {
+					/*
+					 * We don't have the initial data
+					 * offset for this packet, which
+					 * means this is the first
+					 * data record for that packet.
+					 * Save the offset of the
+					 * beginning of that record and
+					 * the offset of the first data
+					 * byte in the packet, which is
+					 * the first data byte in the
+					 * record.
+					 */
+					pkt->id_offset = pkt->cd_offset;
+					pkt->sd_offset = state->offset;
+				}
+
+				if (n == 0)
+					continue;
+
+				ws_assert(num_bytes_to_skip < n);
+				while (num_bytes_to_skip) {
+					if (file_getc(fh) == EOF)
+						goto done;
+					state->offset++;
+					num_bytes_to_skip--;
+					n--;
+				}
+				num_written = process_data(state, fh, pkt, n,
+				    pd, err, err_info, pid);
+
+				if (num_written < 0) {
+					return FALSE;
+				}
+				else if (num_written > 0) {
+					*num_bytes = num_written;
+					*direction = pkt->dir;
+					return TRUE;
+				}
+				/* if 0 bytes written, keep looping */
+				break;
+
+			case PPPD_SEND_DELIM:
+			case PPPD_RECV_DELIM:
+				/* What can we do? */
+				break;
+
+			case PPPD_RESET_TIME:
+				if (!wtap_read_bytes(fh, &time_long, sizeof(guint32), err, err_info))
+					return FALSE;
+				state->offset += sizeof(guint32);
+				state->timestamp = pntoh32(&time_long);
+				state->tenths = 0;
+				break;
+
+			case PPPD_TIME_STEP_LONG:
+				if (!wtap_read_bytes(fh, &time_long, sizeof(guint32), err, err_info))
+					return FALSE;
+				state->offset += sizeof(guint32);
+				state->tenths += pntoh32(&time_long);
+
+				if (state->tenths >= 10) {
+					state->timestamp += state->tenths / 10;
+					state->tenths = state->tenths % 10;
+				}
+
+				break;
+
+			case PPPD_TIME_STEP_SHORT:
+				if (!wtap_read_bytes(fh, &time_short, sizeof(guint8), err, err_info))
+					return FALSE;
+				state->offset += sizeof(guint8);
+				state->tenths += time_short;
+
+				if (state->tenths >= 10) {
+					state->timestamp += state->tenths / 10;
+					state->tenths = state->tenths % 10;
+				}
+
+				break;
+
+			default:
+				/* XXX - bad file */
+				*err = WTAP_ERR_BAD_FILE;
+				*err_info = ws_strdup_printf("pppdump: bad ID byte 0x%02x", id);
+				return FALSE;
+		}
+
+	}
+
+done:
+	*err = file_error(fh, err_info);
+	if (*err == 0) {
+		if (state->offset != start_offset) {
+			/*
+			 * We read at least one byte, so we were working
+			 * on a record; an EOF means that record was
+			 * cut short.
+			 */
+			*err = WTAP_ERR_SHORT_READ;
+		}
+	}
+	return FALSE;
+}
+
+
+
+/* Used to read packets in random-access fashion */
+static gboolean
+pppdump_seek_read(wtap *wth,
+		 gint64 seek_off,
+		 wtap_rec *rec,
+		 Buffer *buf,
+		 int *err,
+		 gchar **err_info)
+{
+	int		num_bytes;
+	guint8		*pd;
+	direction_enum	direction;
+	pppdump_t	*state;
+	pkt_id		*pid;
+	gint64		num_bytes_to_skip;
+
+	state = (pppdump_t *)wth->priv;
+
+	pid = (pkt_id *)g_ptr_array_index(state->pids, seek_off);
+	if (!pid) {
+		*err = WTAP_ERR_BAD_FILE;	/* XXX - better error? */
+		*err_info = g_strdup("pppdump: PID not found for record");
+		return FALSE;
+	}
+
+	if (file_seek(wth->random_fh, pid->offset, SEEK_SET, err) == -1)
+		return FALSE;
+
+	init_state(state->seek_state);
+	state->seek_state->offset = pid->offset;
+
+	ws_buffer_assure_space(buf, PPPD_BUF_SIZE);
+	pd = ws_buffer_start_ptr(buf);
+
+	/*
+	 * We'll start reading at the first record containing data from
+	 * this packet; however, that doesn't mean "collate()" will
+	 * stop only when we've read that packet, as there might be
+	 * data for packets going in the other direction as well, and
+	 * we might finish processing one of those packets before we
+	 * finish processing the packet we're reading.
+	 *
+	 * Therefore, we keep reading until we get a packet that's
+	 * going in the direction we want.
+	 */
+	num_bytes_to_skip = pid->num_bytes_to_skip;
+	do {
+		if (!collate(state->seek_state, wth->random_fh, err, err_info,
+		    pd, &num_bytes, &direction, NULL, num_bytes_to_skip))
+			return FALSE;
+		num_bytes_to_skip = 0;
+	} while (direction != pid->dir);
+
+	pppdump_set_phdr(rec, num_bytes, pid->dir);
+
+	return TRUE;
+}
+
+static void
+pppdump_close(wtap *wth)
+{
+	pppdump_t	*state;
+
+	state = (pppdump_t *)wth->priv;
+
+	if (state->seek_state) { /* should always be TRUE */
+		g_free(state->seek_state);
+	}
+
+	if (state->pids) {
+		unsigned int i;
+		for (i = 0; i < g_ptr_array_len(state->pids); i++) {
+			g_free(g_ptr_array_index(state->pids, i));
+		}
+		g_ptr_array_free(state->pids, TRUE);
+	}
+}
+
+static const struct supported_block_type pppdump_blocks_supported[] = {
+	/*
+	 * We support packet blocks, with no comments or other options.
+	 */
+	{ WTAP_BLOCK_PACKET, MULTIPLE_BLOCKS_SUPPORTED, NO_OPTIONS_SUPPORTED }
+};
+
+static const struct file_type_subtype_info pppdump_info = {
+	"pppd log (pppdump format)", "pppd", NULL, NULL,
+	FALSE, BLOCKS_SUPPORTED(pppdump_blocks_supported),
+	NULL, NULL, NULL
+};
+
+void register_pppdump(void)
+{
+	pppdump_file_type_subtype = wtap_register_file_type_subtype(&pppdump_info);
+
+	/*
+	 * Register name for backwards compatibility with the
+	 * wtap_filetypes table in Lua.
+	 */
+	wtap_register_backwards_compatibility_lua_name("PPPDUMP",
+	    pppdump_file_type_subtype);
+}
+
+/*
+ * Editor modelines  -  https://www.wireshark.org/tools/modelines.html
+ *
+ * Local variables:
+ * c-basic-offset: 8
+ * tab-width: 8
+ * indent-tabs-mode: t
+ * End:
+ *
+ * vi: set shiftwidth=8 tabstop=8 noexpandtab:
+ * :indentSize=8:tabSize=8:noTabs=false:
+ */