Re: [Bugme-new] [Bug 8405] New: pppd does stops compresion with "Lost compression sync"
From: Richard Purdie <hidden>
Date: 2007-05-01 21:23:04
On Tue, 2007-05-01 at 09:27 +0200, Stefan Wenk wrote:
Now I have changed these modifications back, and I do not see more debug information except those below: z_decompress0: Would have triggered an error as inflate returned -5 () z_decompress0: Would have triggered an error as inflate returned -5 () z_decompress0: Would have triggered an error as inflate returned -5 () .. As there are no debug logs in inflate.c I can't provide more information by now.
I had a look at that trace you sent, the echo and replys were normal but obviously something is going wrong and it tries to negotiate turning off the compression... Having looked at the code a bit further, I have a theory that it was impossible to reach the zlib_inflateSyncPacket call ppp deflate needs. The patch below fixes that and also adds some debugging so if that isn't the problem, we might get some further clues as to what the problem is... Thanks for the patience :) Richard Index: linux/drivers/net/ppp_deflate.c ===================================================================
--- linux.orig/drivers/net/ppp_deflate.c 2007-01-18 00:52:50.000000000 +0000
+++ linux/drivers/net/ppp_deflate.c 2007-05-01 22:21:27.000000000 +0100@@ -488,6 +488,13 @@ int z_decompress(void *arg, unsigned cha for (;;) { r = zlib_inflate(&state->strm, Z_PACKET_FLUSH); if (r != Z_OK) { + printk(KERN_ERR "z_decompress%d: inflate returned %d (%s)" + ",av in %d, av out %d, t in %ld, t out %ld, dp %d," + " of %d, is %d, os %d\n", + state->unit, r, (state->strm.msg? state->strm.msg: ""), + state->strm.avail_in, state->strm.avail_out, + state->strm.total_in, state->strm.total_out, + decode_proto, overflow, isize, osize); if (state->debug) printk(KERN_DEBUG "z_decompress%d: inflate returned %d (%s)\n", state->unit, r, (state->strm.msg? state->strm.msg: ""));
Index: linux/lib/zlib_inflate/inflate.c ===================================================================
--- linux.orig/lib/zlib_inflate/inflate.c 2007-01-18 00:53:08.000000000 +0000
+++ linux/lib/zlib_inflate/inflate.c 2007-05-01 22:03:53.000000000 +0100@@ -743,12 +743,14 @@ int zlib_inflate(z_streamp strm, int flu strm->data_type = state->bits + (state->last ? 64 : 0) + (state->mode == TYPE ? 128 : 0); - if (((in == 0 && out == 0) || flush == Z_FINISH) && ret == Z_OK) - ret = Z_BUF_ERROR; if (flush == Z_PACKET_FLUSH && ret == Z_OK && (strm->avail_out != 0 || strm->avail_in == 0)) return zlib_inflateSyncPacket(strm); + + if (((in == 0 && out == 0) || flush == Z_FINISH) && ret == Z_OK) + ret = Z_BUF_ERROR; + return ret; }