From faca42daa4d3166e0af50cd1b33dc607a0f63af1 Mon Sep 17 00:00:00 2001 From: Tatsuhiro Tsujikawa Date: Sat, 9 Mar 2024 16:26:42 +0900 Subject: [PATCH] Limit CONTINUATION frames following an incoming HEADER frame (cherry picked from commit 00201ecd8f982da3b67d4f6868af72a1b03b14e0) Signed-off-by: Jan Macku Add nghttp2_option_set_max_continuations (cherry picked from commit d71a4668c6bead55805d18810d633fbb98315af9) Signed-off-by: Jan Macku --- doc/Makefile.am | 1 + lib/includes/nghttp2/nghttp2.h | 18 +++++++++++++++++- lib/nghttp2_helper.c | 2 ++ lib/nghttp2_option.c | 5 +++++ lib/nghttp2_option.h | 5 +++++ lib/nghttp2_session.c | 11 +++++++++++ lib/nghttp2_session.h | 10 ++++++++++ 7 files changed, 51 insertions(+), 1 deletion(-) diff --git a/doc/Makefile.am b/doc/Makefile.am index f8d7b48f..39d0d304 100644 --- a/doc/Makefile.am +++ b/doc/Makefile.am @@ -68,6 +68,7 @@ APIDOCS= \ nghttp2_option_set_no_recv_client_magic.rst \ nghttp2_option_set_peer_max_concurrent_streams.rst \ nghttp2_option_set_user_recv_extension_type.rst \ + nghttp2_option_set_max_continuations.rst \ nghttp2_option_set_max_outbound_ack.rst \ nghttp2_option_set_max_settings.rst \ nghttp2_option_set_stream_reset_rate_limit.rst \ diff --git a/lib/includes/nghttp2/nghttp2.h b/lib/includes/nghttp2/nghttp2.h index 1f2a3b93..1137e645 100644 --- a/lib/includes/nghttp2/nghttp2.h +++ b/lib/includes/nghttp2/nghttp2.h @@ -440,7 +440,12 @@ typedef enum { * exhaustion on server side to send these frames forever and does * not read network. */ - NGHTTP2_ERR_FLOODED = -904 + NGHTTP2_ERR_FLOODED = -904, + /** + * When a local endpoint receives too many CONTINUATION frames + * following a HEADER frame. + */ + NGHTTP2_ERR_TOO_MANY_CONTINUATIONS = -905, } nghttp2_error; /** @@ -2736,6 +2741,17 @@ NGHTTP2_EXTERN void nghttp2_option_set_stream_reset_rate_limit(nghttp2_option *option, uint64_t burst, uint64_t rate); +/** + * @function + * + * This function sets the maximum number of CONTINUATION frames + * following an incoming HEADER frame. If more than those frames are + * received, the remote endpoint is considered to be misbehaving and + * session will be closed. The default value is 8. + */ +NGHTTP2_EXTERN void nghttp2_option_set_max_continuations(nghttp2_option *option, + size_t val); + /** * @function * diff --git a/lib/nghttp2_helper.c b/lib/nghttp2_helper.c index 0bd54147..4158a0b0 100644 --- a/lib/nghttp2_helper.c +++ b/lib/nghttp2_helper.c @@ -336,6 +336,8 @@ const char *nghttp2_strerror(int error_code) { "closed"; case NGHTTP2_ERR_TOO_MANY_SETTINGS: return "SETTINGS frame contained more than the maximum allowed entries"; + case NGHTTP2_ERR_TOO_MANY_CONTINUATIONS: + return "Too many CONTINUATION frames following a HEADER frame"; default: return "Unknown error code"; } diff --git a/lib/nghttp2_option.c b/lib/nghttp2_option.c index 0d9a4044..f3659c18 100644 --- a/lib/nghttp2_option.c +++ b/lib/nghttp2_option.c @@ -133,3 +133,8 @@ void nghttp2_option_set_stream_reset_rate_limit(nghttp2_option *option, option->stream_reset_burst = burst; option->stream_reset_rate = rate; } + +void nghttp2_option_set_max_continuations(nghttp2_option *option, size_t val) { + option->opt_set_mask |= NGHTTP2_OPT_MAX_CONTINUATIONS; + option->max_continuations = val; +} diff --git a/lib/nghttp2_option.h b/lib/nghttp2_option.h index e6ba9100..c1b48c73 100644 --- a/lib/nghttp2_option.h +++ b/lib/nghttp2_option.h @@ -69,6 +69,7 @@ typedef enum { NGHTTP2_OPT_MAX_OUTBOUND_ACK = 1 << 11, NGHTTP2_OPT_MAX_SETTINGS = 1 << 12, NGHTTP2_OPT_STREAM_RESET_RATE_LIMIT = 1 << 15, + NGHTTP2_OPT_MAX_CONTINUATIONS = 1 << 16, } nghttp2_option_flag; /** @@ -96,6 +97,10 @@ struct nghttp2_option { * NGHTTP2_OPT_MAX_SETTINGS */ size_t max_settings; + /** + * NGHTTP2_OPT_MAX_CONTINUATIONS + */ + size_t max_continuations; /** * Bitwise OR of nghttp2_option_flag to determine that which fields * are specified. diff --git a/lib/nghttp2_session.c b/lib/nghttp2_session.c index 80072d21..3e11bd8f 100644 --- a/lib/nghttp2_session.c +++ b/lib/nghttp2_session.c @@ -464,6 +464,7 @@ static int session_new(nghttp2_session **session_ptr, (*session_ptr)->max_send_header_block_length = NGHTTP2_MAX_HEADERSLEN; (*session_ptr)->max_outbound_ack = NGHTTP2_DEFAULT_MAX_OBQ_FLOOD_ITEM; (*session_ptr)->max_settings = NGHTTP2_DEFAULT_MAX_SETTINGS; + (*session_ptr)->max_continuations = NGHTTP2_DEFAULT_MAX_CONTINUATIONS; if (option) { if ((option->opt_set_mask & NGHTTP2_OPT_NO_AUTO_WINDOW_UPDATE) && @@ -538,6 +539,10 @@ static int session_new(nghttp2_session **session_ptr, option->stream_reset_burst, option->stream_reset_rate); } + + if (option->opt_set_mask & NGHTTP2_OPT_MAX_CONTINUATIONS) { + (*session_ptr)->max_continuations = option->max_continuations; + } } rv = nghttp2_hd_deflate_init2(&(*session_ptr)->hd_deflater, @@ -6309,6 +6314,8 @@ ssize_t nghttp2_session_mem_recv(nghttp2_session *session, const uint8_t *in, } } session_inbound_frame_reset(session); + + session->num_continuations = 0; } break; } @@ -6430,6 +6437,10 @@ ssize_t nghttp2_session_mem_recv(nghttp2_session *session, const uint8_t *in, } #endif /* DEBUGBUILD */ + if (++session->num_continuations > session->max_continuations) { + return NGHTTP2_ERR_TOO_MANY_CONTINUATIONS; + } + readlen = inbound_frame_buf_read(iframe, in, last); in += readlen; diff --git a/lib/nghttp2_session.h b/lib/nghttp2_session.h index 9d429921..d8f9c395 100644 --- a/lib/nghttp2_session.h +++ b/lib/nghttp2_session.h @@ -107,6 +107,10 @@ typedef struct { #define NGHTTP2_DEFAULT_STREAM_RESET_BURST 1000 #define NGHTTP2_DEFAULT_STREAM_RESET_RATE 33 +/* The default max number of CONTINUATION frames following an incoming + HEADER frame. */ +#define NGHTTP2_DEFAULT_MAX_CONTINUATIONS 8 + /* Internal state when receiving incoming frame */ typedef enum { /* Receiving frame header */ @@ -279,6 +283,12 @@ struct nghttp2_session { size_t max_send_header_block_length; /* The maximum number of settings accepted per SETTINGS frame. */ size_t max_settings; + /* The maximum number of CONTINUATION frames following an incoming + HEADER frame. */ + size_t max_continuations; + /* The number of CONTINUATION frames following an incoming HEADER + frame. This variable is reset when END_HEADERS flag is seen. */ + size_t num_continuations; /* Next Stream ID. Made unsigned int to detect >= (1 << 31). */ uint32_t next_stream_id; /* The last stream ID this session initiated. For client session, -- 2.44.0