diff options
| -rw-r--r-- | usr.sbin/ppp/deflate.c | 27 |
1 files changed, 21 insertions, 6 deletions
diff --git a/usr.sbin/ppp/deflate.c b/usr.sbin/ppp/deflate.c index 6ef6e98..3adf2e9 100644 --- a/usr.sbin/ppp/deflate.c +++ b/usr.sbin/ppp/deflate.c @@ -23,7 +23,7 @@ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. * - * $Id$ + * $Id: deflate.c,v 1.4 1997/12/21 12:11:04 brian Exp $ */ #include <sys/param.h> @@ -50,6 +50,7 @@ /* Our state */ struct deflate_state { u_short seqno; + int dodgy_seqno; z_stream cx; }; @@ -65,6 +66,7 @@ static void DeflateResetOutput(void) { OutputState.seqno = 0; + OutputState.dodgy_seqno = 0; deflateReset(&OutputState.cx); LogPrintf(LogCCP, "Deflate: Output channel reset\n"); } @@ -190,6 +192,7 @@ static void DeflateResetInput(void) { InputState.seqno = 0; + InputState.dodgy_seqno = 0; inflateReset(&InputState.cx); LogPrintf(LogCCP, "Deflate: Input channel reset\n"); } @@ -211,13 +214,18 @@ DeflateInput(u_short *proto, struct mbuf *mi) seq = (hdr[0] << 8) + hdr[1]; LogPrintf(LogDEBUG, "DeflateInput: Seq %d\n", seq); if (seq != InputState.seqno) { - LogPrintf(LogERROR, "DeflateInput: Seq error: Got %d, expected %d\n", - seq, InputState.seqno); - pfree(mi_head); - CcpSendResetReq(&CcpFsm); - return NULL; + if (InputState.dodgy_seqno && seq < InputState.seqno) + InputState.seqno = seq; + else { + LogPrintf(LogERROR, "DeflateInput: Seq error: Got %d, expected %d\n", + seq, InputState.seqno); + pfree(mi_head); + CcpSendResetReq(&CcpFsm); + return NULL; + } } InputState.seqno++; + InputState.dodgy_seqno = 0; /* Allocate an output mbuf */ mo_head = mo = mballoc(DEFLATE_CHUNK_LEN, MB_IPIN); @@ -525,6 +533,13 @@ DeflateInitInput(void) if (inflateInit2(&InputState.cx, -iWindowSize) != Z_OK) return 0; DeflateResetInput(); + /* + * When we begin, we may start adding to our dictionary before the + * peer does. If `dodgy_seqno' is set, we'll allow the peer to send + * us a seqno that's too small and just adjust seqno accordingly - + * deflate is a sliding window compressor ! + */ + InputState.dodgy_seqno = 1; return 1; } |
