7006bd42d5
When a STREAM frame is re-emitted, it will point to the same stream buffer as the original one. If an ACK is received for either one of these frame, the underlying buffer may be freed. Thus, if the second frame is declared as lost and schedule for retransmission, we must ensure that the underlying buffer is still allocated or interrupt the retransmission. Stream buffer is stored as an eb_tree indexed by the stream ID. To avoid to lookup over a tree each time a STREAM frame is re-emitted, a lost STREAM frame is flagged as QUIC_FL_TX_FRAME_LOST. In most cases, this code is functional. However, there is several potential issues which may cause a segfault : - when explicitely probing with a STREAM frame, the frame won't be flagged as lost - when splitting a STREAM frame during retransmission, the flag is not copied To fix both these cases, QUIC_FL_TX_FRAME_LOST flag has been converted to a <dup> field in quic_stream structure. This field is now properly copied when splitting a STREAM frame. Also, as this is now an inner quic_frame field, it will be copied automatically on qc_frm_dup() invocation thus ensuring that it will be set on probing. This issue was encounted randomly with the following backtrace : #0 __memmove_avx512_unaligned_erms () #1 0x000055f4d5a48c01 in memcpy (__len=18446698486215405173, __src=<optimized out>, #2 quic_build_stream_frame (buf=0x7f6ac3fcb400, end=<optimized out>, frm=0x7f6a00556620, #3 0x000055f4d5a4a147 in qc_build_frm (buf=buf@entry=0x7f6ac3fcb5d8, #4 0x000055f4d5a23300 in qc_do_build_pkt (pos=<optimized out>, end=<optimized out>, #5 0x000055f4d5a25976 in qc_build_pkt (pos=0x7f6ac3fcba10, #6 0x000055f4d5a30c7e in qc_prep_app_pkts (frms=0x7f6a0032bc50, buf=0x7f6a0032bf30, #7 qc_send_app_pkts (qc=0x7f6a0032b310, frms=0x7f6a0032bc50) at src/quic_conn.c:4184 #8 0x000055f4d5a35f42 in quic_conn_app_io_cb (t=0x7f6a0009c660, context=0x7f6a0032b310, This should fix github issue #2051. This should be backported up to 2.6. (cherry picked from commit c8a0efbda86a14af38084ce85933bb691563935c) Signed-off-by: William Lallemand <wlallemand@haproxy.org> (cherry picked from commit 85ab1edd1549c4eb4680543d7f86c3065fbaf30e) [ad: remove block which rejects frame on too many retransmission] Signed-off-by: Amaury Denoyelle <adenoyelle@haproxy.com>
The HAProxy documentation has been split into a number of different files for ease of use. Please refer to the following files depending on what you're looking for : - INSTALL for instructions on how to build and install HAProxy - BRANCHES to understand the project's life cycle and what version to use - LICENSE for the project's license - CONTRIBUTING for the process to follow to submit contributions The more detailed documentation is located into the doc/ directory : - doc/intro.txt for a quick introduction on HAProxy - doc/configuration.txt for the configuration's reference manual - doc/lua.txt for the Lua's reference manual - doc/SPOE.txt for how to use the SPOE engine - doc/network-namespaces.txt for how to use network namespaces under Linux - doc/management.txt for the management guide - doc/regression-testing.txt for how to use the regression testing suite - doc/peers.txt for the peers protocol reference - doc/coding-style.txt for how to adopt HAProxy's coding style - doc/internals for developer-specific documentation (not all up to date)