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fix(gateway): reassemble WebChat frames before JSON parse #144

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3 changes: 3 additions & 0 deletions CHANGELOG.md
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Original file line number Diff line number Diff line change
Expand Up @@ -4,6 +4,9 @@ All notable changes to ShellClaw are documented here. Format follows [Keep a Cha

## [Unreleased]

### Fixed
- WebChat reassembles libwebsockets receive spills before parsing, so a chat message whose JSON escapes grow past the 32 KiB + 64 byte callback buffer reaches the agent instead of being dropped.

## [1.0.1] - 2026-10-18

### Fixed
Expand Down
24 changes: 17 additions & 7 deletions Makefile
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Original file line number Diff line number Diff line change
Expand Up @@ -100,6 +100,7 @@ HTTP_LWS_O := $(if $(filter 1,$(GATEWAY)),src/gateway/http_lws.o,)
ROUTES_O := $(if $(filter 1,$(GATEWAY)),src/gateway/routes.o,)
ROUTES_HARDWARE_O := $(if $(filter 1,$(GATEWAY)),src/gateway/routes_hardware.o,)
WS_O := $(if $(filter 1,$(GATEWAY)),src/gateway/ws.o,)
WS_RX_O := $(if $(filter 1,$(GATEWAY)),src/gateway/ws_rx.o,)
# Tools (Task 7)
SHELL_O := src/tools/shell.o
WEBSEARCH_O := src/tools/web_search.o
Expand Down Expand Up @@ -172,7 +173,7 @@ OBJS := $(CORE_OBJS) $(VENDOR_OBJS)
PROVIDER_OBJS := $(PROVIDER_COMMON_O) $(STUB_O) $(ROUTER_O) $(ANTHROPIC_O) $(OPENAI_COMPAT_O) $(OPENAI_O) $(LOCAL_O)
CHANNEL_OBJS := $(CHANNEL_COMMON_O) $(CHANNEL_CLI_O) $(CHANNEL_TG_O) $(CHANNEL_DISCORD_O) $(DISCORD_HELPERS_O) $(CHANNEL_HEARTBEAT_O) $(CHANNEL_WEBCHAT_O)
ASAP_HTTP_BODY_O := $(if $(filter 1,$(GATEWAY)),src/gateway/asap_http_body.o,)
GATEWAY_OBJS := $(AUTH_O) $(STATIC_O) $(HTTP_O) $(HTTP_LWS_O) $(ASAP_HTTP_BODY_O) $(ROUTES_O) $(ROUTES_HARDWARE_O) $(WS_O) $(RATE_LIMIT_O)
GATEWAY_OBJS := $(AUTH_O) $(STATIC_O) $(HTTP_O) $(HTTP_LWS_O) $(ASAP_HTTP_BODY_O) $(ROUTES_O) $(ROUTES_HARDWARE_O) $(WS_O) $(WS_RX_O) $(RATE_LIMIT_O)
TOOL_OBJS := $(SHELL_O) $(WEBSEARCH_O) $(FILE_O) $(REGISTRY_O) $(CONTEXT_O) $(CONTEXT_CACHE_O) $(CONTEXT_HTTP_O) $(CONTEXT_GEO_O) $(CRYPTO_LINK) $(HARDWARE_STUB_O) $(HARDWARE_INIT_O) $(HARDWARE_GPIO_SNAPSHOT_O) $(HARDWARE_TEGRASTATS_O) $(HARDWARE_TOOLS_O) $(BOARD_DETECT_O) $(HARDWARE_I2C_O) $(HARDWARE_CAMERA_O) $(HARDWARE_LIBGPIOD_O) $(CRON_O) $(ASAP_INVOKE_O)
ASAP_OBJS := $(MANIFEST_O) $(MANIFEST_PROFILES_O) $(MANIFEST_BUILD_O) $(MANIFEST_SIGN_O) $(MANIFEST_KEYS_O) $(JCS_O) $(ENVELOPE_O) $(ULID_O) $(CLIENT_O) $(ASAP_REGISTRY_O) $(SERVER_O) $(ASAP_LOG_O)
SANDBOX_OBJS := $(SANDBOX_O) $(ALLOWLIST_O)
Expand Down Expand Up @@ -386,6 +387,9 @@ $(ROUTES_HARDWARE_O): src/gateway/routes_hardware.c src/gateway/routes_hardware.
$(WS_O): src/gateway/ws.c src/gateway/ws.h
$(CC) $(CFLAGS) $(INC) $(GATEWAY_CFLAGS) -c -o $@ src/gateway/ws.c

src/gateway/ws_rx.o: src/gateway/ws_rx.c src/gateway/ws.h vendor/cJSON/cJSON.h
$(CC) $(CFLAGS) $(INC) -c -o $@ src/gateway/ws_rx.c

$(SHELL_O): src/tools/shell.c src/tools/tool.h src/tools/shell.h src/core/config.h \
src/sandbox/sandbox.h src/sandbox/allowlist.h
$(CC) $(CFLAGS) $(INC) -c -o $@ src/tools/shell.c
Expand Down Expand Up @@ -647,9 +651,14 @@ test_cron: tests/test_cron.c $(CRON_O) $(CRYPTO_LINK) $(MEMORY_O) $(SQLITE3_O) $
$(CC) $(CFLAGS) $(LDFLAGS) $(INC) -o $(BINDIR)/$@ tests/test_cron.c $(CRON_O) $(CRYPTO_LINK) $(MEMORY_O) $(SQLITE3_O) $(CHANNEL_COMMON_O) $(CJSON_O) $(AGENT_O) $(SKILL_O) $(CONFIG_O) $(TOML_O) $(PROVIDER_COMMON_O) $(LDLIBS) -pthread
$(DSYM_SCRIPT)

test_ws: tests/test_ws.c $(WS_TEST_O)
test_ws: tests/test_ws.c $(WS_TEST_O) src/gateway/ws_rx.o $(CJSON_O)
@mkdir -p $(BINDIR)
$(CC) $(CFLAGS) $(LDFLAGS) $(INC) -o $(BINDIR)/$@ tests/test_ws.c $(WS_TEST_O) src/gateway/ws_rx.o $(CJSON_O) $(LDLIBS) -pthread
$(DSYM_SCRIPT)

test_ws_rx: tests/test_ws_rx.c $(WS_TEST_O) src/gateway/ws_rx.o $(CJSON_O)
@mkdir -p $(BINDIR)
$(CC) $(CFLAGS) $(LDFLAGS) $(INC) -o $(BINDIR)/$@ tests/test_ws.c $(WS_TEST_O) $(LDLIBS) -pthread
$(CC) $(CFLAGS) $(LDFLAGS) $(INC) -o $(BINDIR)/$@ tests/test_ws_rx.c $(WS_TEST_O) src/gateway/ws_rx.o $(CJSON_O) $(LDLIBS) -pthread
$(DSYM_SCRIPT)

test_context: tests/test_context.c $(CONTEXT_TEST_OBJS) $(CONFIG_O) $(TOML_O) $(CJSON_O)
Expand Down Expand Up @@ -865,7 +874,7 @@ static:
--suppress=variableScope:src/vendor/tweetnacl/tweetnacl.c \
-q src/

test: test_config test_config_patch test_memory test_skill test_provider test_anthropic test_openai test_local_provider test_router test_heartbeat test_agent test_reload test_channel test_cli test_shell test_file test_telegram test_discord_helpers test_web_search test_cron test_context test_dispatch test_crypto test_hardware_stub test_board_detect test_hardware_libgpiod test_hardware_i2c test_hardware_camera test_pin_tables test_hardware_init test_hardware_gpio_snapshot test_hardware_tegrastats test_hardware_tools test_registry test_ws test_manifest $(ASAP_UNIT_TESTS) test_sandbox test_allowlist test_rate_limit test_daemon_smoke test_bootstrap_keys test_update_script test_install_script test_download_model test_web_dashboard test_routes_hardware
test: test_config test_config_patch test_memory test_skill test_provider test_anthropic test_openai test_local_provider test_router test_heartbeat test_agent test_reload test_channel test_cli test_shell test_file test_telegram test_discord_helpers test_web_search test_cron test_context test_dispatch test_crypto test_hardware_stub test_board_detect test_hardware_libgpiod test_hardware_i2c test_hardware_camera test_pin_tables test_hardware_init test_hardware_gpio_snapshot test_hardware_tegrastats test_hardware_tools test_registry test_ws test_ws_rx test_manifest $(ASAP_UNIT_TESTS) test_sandbox test_allowlist test_rate_limit test_daemon_smoke test_bootstrap_keys test_update_script test_install_script test_download_model test_web_dashboard test_routes_hardware
$(BINDIR)/test_config
$(BINDIR)/test_config_patch
$(BINDIR)/test_memory
Expand Down Expand Up @@ -901,6 +910,7 @@ test: test_config test_config_patch test_memory test_skill test_provider test_an
$(BINDIR)/test_hardware_tools
$(BINDIR)/test_registry
$(BINDIR)/test_ws
$(BINDIR)/test_ws_rx
@for t in $(ASAP_UNIT_TESTS); do $(BINDIR)/$$t || exit 1; done
$(BINDIR)/test_sandbox
$(BINDIR)/test_allowlist
Expand All @@ -922,7 +932,7 @@ COVERAGE_DIR := build/coverage
COVERAGE_MIN := 80

coverage: clean
$(MAKE) BUILD=coverage GATEWAY=0 test_config test_config_patch test_memory test_skill test_provider test_anthropic test_openai test_local_provider test_router test_heartbeat test_agent test_reload test_channel test_cli test_shell test_file test_telegram test_discord_helpers test_web_search test_cron test_context test_dispatch test_crypto test_hardware_stub test_board_detect test_hardware_libgpiod test_hardware_i2c test_hardware_camera test_pin_tables test_hardware_init test_hardware_gpio_snapshot test_hardware_tegrastats test_hardware_tools test_registry test_ws test_manifest_build test_manifest_keys test_jcs $(ASAP_UNIT_TESTS) test_sandbox test_allowlist test_rate_limit test_auth
$(MAKE) BUILD=coverage GATEWAY=0 test_config test_config_patch test_memory test_skill test_provider test_anthropic test_openai test_local_provider test_router test_heartbeat test_agent test_reload test_channel test_cli test_shell test_file test_telegram test_discord_helpers test_web_search test_cron test_context test_dispatch test_crypto test_hardware_stub test_board_detect test_hardware_libgpiod test_hardware_i2c test_hardware_camera test_pin_tables test_hardware_init test_hardware_gpio_snapshot test_hardware_tegrastats test_hardware_tools test_registry test_ws test_ws_rx test_manifest_build test_manifest_keys test_jcs $(ASAP_UNIT_TESTS) test_sandbox test_allowlist test_rate_limit test_auth

@if [ "$(GATEWAY)" = "1" ]; then $(MAKE) BUILD=coverage GATEWAY=1 shellclaw test_gateway_http test_static; fi
@chmod +x scripts/coverage.sh
Expand All @@ -934,9 +944,9 @@ clean-root-dsym:
@rm -f shellclaw test_agent test_anthropic test_channel test_cli test_config test_file test_memory test_local_provider test_openai test_provider test_router test_shell test_skill test_telegram test_web_search test_ws

clean: clean-root-dsym
rm -f $(OBJS) $(PROVIDER_COMMON_O) $(STUB_O) $(ANTHROPIC_O) $(OPENAI_COMPAT_O) $(OPENAI_O) $(LOCAL_O) $(ROUTER_O) $(CJSON_O) $(TWEETNACL_O) $(ANTHROPIC_TEST_O) $(OPENAI_TEST_O) $(LOCAL_TEST_O) $(CONTEXT_TEST_OBJS) $(HEARTBEAT_TEST_O) $(CHANNEL_TG_TEST_O) $(CHANNEL_COMMON_O) $(CHANNEL_STUB_O) $(CHANNEL_CLI_O) $(CHANNEL_TG_O) $(CHANNEL_DISCORD_O) $(DISCORD_HELPERS_O) $(CHANNEL_HEARTBEAT_O) $(CHANNEL_WEBCHAT_O) $(AUTH_O) $(STATIC_O) $(HTTP_O) $(HTTP_LWS_O) $(ASAP_HTTP_BODY_O) $(ROUTES_O) $(ROUTES_HARDWARE_O) $(WS_O) $(MANIFEST_O) $(MANIFEST_PROFILES_O) $(MANIFEST_BUILD_O) $(MANIFEST_SIGN_O) $(MANIFEST_KEYS_O) $(ENVELOPE_O) $(ULID_O) $(CLIENT_O) $(ASAP_REGISTRY_O) $(SERVER_O) $(ASAP_LOG_O) $(RATE_LIMIT_O) $(SHELL_O) $(WEBSEARCH_O) $(FILE_O) $(REGISTRY_O) $(CONTEXT_O) $(CONTEXT_CACHE_O) $(CONTEXT_HTTP_O) $(CONTEXT_GEO_O) $(CRYPTO_O) $(JCS_O) $(HARDWARE_STUB_O) $(HARDWARE_INIT_O) $(HARDWARE_GPIO_SNAPSHOT_O) $(HARDWARE_TEGRASTATS_O) $(HARDWARE_TOOLS_O) $(BOARD_DETECT_O) src/hardware/hardware_libgpiod.o $(HARDWARE_I2C_O) $(HARDWARE_CAMERA_O) $(CRON_O) $(ASAP_INVOKE_O) $(SANDBOX_CORE_O) $(SANDBOX_LANDLOCK_O) $(SANDBOX_ENV_O) $(ALLOWLIST_SCAN_O) $(ALLOWLIST_PATH_O)
rm -f $(OBJS) $(PROVIDER_COMMON_O) $(STUB_O) $(ANTHROPIC_O) $(OPENAI_COMPAT_O) $(OPENAI_O) $(LOCAL_O) $(ROUTER_O) $(CJSON_O) $(TWEETNACL_O) $(ANTHROPIC_TEST_O) $(OPENAI_TEST_O) $(LOCAL_TEST_O) $(CONTEXT_TEST_OBJS) $(HEARTBEAT_TEST_O) $(CHANNEL_TG_TEST_O) $(CHANNEL_COMMON_O) $(CHANNEL_STUB_O) $(CHANNEL_CLI_O) $(CHANNEL_TG_O) $(CHANNEL_DISCORD_O) $(DISCORD_HELPERS_O) $(CHANNEL_HEARTBEAT_O) $(CHANNEL_WEBCHAT_O) $(AUTH_O) $(STATIC_O) $(HTTP_O) $(HTTP_LWS_O) $(ASAP_HTTP_BODY_O) $(ROUTES_O) $(ROUTES_HARDWARE_O) $(WS_O) src/gateway/ws_rx.o $(MANIFEST_O) $(MANIFEST_PROFILES_O) $(MANIFEST_BUILD_O) $(MANIFEST_SIGN_O) $(MANIFEST_KEYS_O) $(ENVELOPE_O) $(ULID_O) $(CLIENT_O) $(ASAP_REGISTRY_O) $(SERVER_O) $(ASAP_LOG_O) $(RATE_LIMIT_O) $(SHELL_O) $(WEBSEARCH_O) $(FILE_O) $(REGISTRY_O) $(CONTEXT_O) $(CONTEXT_CACHE_O) $(CONTEXT_HTTP_O) $(CONTEXT_GEO_O) $(CRYPTO_O) $(JCS_O) $(HARDWARE_STUB_O) $(HARDWARE_INIT_O) $(HARDWARE_GPIO_SNAPSHOT_O) $(HARDWARE_TEGRASTATS_O) $(HARDWARE_TOOLS_O) $(BOARD_DETECT_O) src/hardware/hardware_libgpiod.o $(HARDWARE_I2C_O) $(HARDWARE_CAMERA_O) $(CRON_O) $(ASAP_INVOKE_O) $(SANDBOX_CORE_O) $(SANDBOX_LANDLOCK_O) $(SANDBOX_ENV_O) $(ALLOWLIST_SCAN_O) $(ALLOWLIST_PATH_O)
rm -f src/gateway/ui_assets.h
find . -name '*.gcno' -o -name '*.gcda' -o -name '*.gcov' | xargs rm -f 2>/dev/null || true
rm -f $(WS_TEST_O) $(SANDBOX_TEST_O) $(BINDIR)/asap_registry_test.o $(BINDIR)/asap_invoke_test.o $(CONTEXT_TEST_OBJS) $(HEARTBEAT_TEST_O) $(BINDIR)/shellclaw $(BINDIR)/test_tweetnacl_smoke $(BINDIR)/test_config $(BINDIR)/test_config_patch $(BINDIR)/test_memory $(BINDIR)/test_skill $(BINDIR)/test_provider $(BINDIR)/test_anthropic $(BINDIR)/test_openai $(BINDIR)/test_local_provider $(BINDIR)/test_router $(BINDIR)/test_heartbeat $(BINDIR)/test_crypto $(BINDIR)/test_hardware_stub $(BINDIR)/test_board_detect $(BINDIR)/test_hardware_libgpiod $(BINDIR)/test_hardware_i2c $(BINDIR)/test_hardware_camera $(BINDIR)/test_pin_tables $(BINDIR)/test_hardware_init $(BINDIR)/test_hardware_tools $(BINDIR)/test_registry $(BINDIR)/test_ws $(BINDIR)/test_agent $(BINDIR)/test_channel $(BINDIR)/test_cli $(BINDIR)/test_shell $(BINDIR)/test_file $(BINDIR)/test_telegram $(BINDIR)/test_discord_helpers $(BINDIR)/test_web_search $(BINDIR)/test_cron $(BINDIR)/test_context $(BINDIR)/test_manifest_build $(BINDIR)/test_manifest_keys $(BINDIR)/test_jcs $(BINDIR)/test_asap_envelope $(BINDIR)/test_asap_ulid $(BINDIR)/test_asap_client $(BINDIR)/test_asap_registry $(BINDIR)/test_asap_server $(BINDIR)/test_asap_invoke $(BINDIR)/test_asap_log $(BINDIR)/test_auth $(BINDIR)/test_gateway_http $(BINDIR)/test_gateway_db_lock $(BINDIR)/test_static $(BINDIR)/test_sandbox $(BINDIR)/test_allowlist $(BINDIR)/test_rate_limit
rm -f $(WS_TEST_O) $(SANDBOX_TEST_O) $(BINDIR)/asap_registry_test.o $(BINDIR)/asap_invoke_test.o $(CONTEXT_TEST_OBJS) $(HEARTBEAT_TEST_O) $(BINDIR)/shellclaw $(BINDIR)/test_tweetnacl_smoke $(BINDIR)/test_config $(BINDIR)/test_config_patch $(BINDIR)/test_memory $(BINDIR)/test_skill $(BINDIR)/test_provider $(BINDIR)/test_anthropic $(BINDIR)/test_openai $(BINDIR)/test_local_provider $(BINDIR)/test_router $(BINDIR)/test_heartbeat $(BINDIR)/test_crypto $(BINDIR)/test_hardware_stub $(BINDIR)/test_board_detect $(BINDIR)/test_hardware_libgpiod $(BINDIR)/test_hardware_i2c $(BINDIR)/test_hardware_camera $(BINDIR)/test_pin_tables $(BINDIR)/test_hardware_init $(BINDIR)/test_hardware_tools $(BINDIR)/test_registry $(BINDIR)/test_ws $(BINDIR)/test_ws_rx $(BINDIR)/test_agent $(BINDIR)/test_channel $(BINDIR)/test_cli $(BINDIR)/test_shell $(BINDIR)/test_file $(BINDIR)/test_telegram $(BINDIR)/test_discord_helpers $(BINDIR)/test_web_search $(BINDIR)/test_cron $(BINDIR)/test_context $(BINDIR)/test_manifest_build $(BINDIR)/test_manifest_keys $(BINDIR)/test_jcs $(BINDIR)/test_asap_envelope $(BINDIR)/test_asap_ulid $(BINDIR)/test_asap_client $(BINDIR)/test_asap_registry $(BINDIR)/test_asap_server $(BINDIR)/test_asap_invoke $(BINDIR)/test_asap_log $(BINDIR)/test_auth $(BINDIR)/test_gateway_http $(BINDIR)/test_gateway_db_lock $(BINDIR)/test_static $(BINDIR)/test_sandbox $(BINDIR)/test_allowlist $(BINDIR)/test_rate_limit
rm -rf $(BINDIR)/*.dSYM $(DSYMDIR)
rm -f $(BOOTSTRAP_DISPATCH_STUB_O) $(TOOL_RELOAD_STUB_O) $(RELOAD_CHANNEL_STUB_O) $(HTTP_RELOAD_STUB_O)
4 changes: 3 additions & 1 deletion src/gateway/http.c
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Original file line number Diff line number Diff line change
Expand Up @@ -42,8 +42,10 @@ static const struct lws_protocols protocols[] = {
{ .name = NULL },
};

_Static_assert(WS_RX_BUFFER_SIZE == WS_RX_SPILL,
"WebChat rx_buffer_size must match the reassembly spill");
_Static_assert(WS_RX_BUFFER_SIZE >= (size_t)WS_TEXT_MAX + 32,
"WebChat rx_buffer_size must fit JSON envelope around WS_TEXT_MAX");
"WebChat rx_buffer_size must fit an unescaped JSON envelope");

static const struct lws_http_mount mount_http = {
.mountpoint = "/",
Expand Down
28 changes: 10 additions & 18 deletions src/gateway/http_lws.c
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Original file line number Diff line number Diff line change
Expand Up @@ -11,7 +11,6 @@
#include "gateway/uri_match.h"
#include "gateway/static.h"
#include "gateway/ws.h"
#include "cJSON.h"
#include <libwebsockets.h>
#include <stdio.h>
#include <stdlib.h>
Expand Down Expand Up @@ -463,23 +462,16 @@ int ws_callback(struct lws *wsi, enum lws_callback_reasons reason, void *user,
}
case LWS_CALLBACK_RECEIVE: {
int conn_id = (int)(intptr_t)lws_wsi_user(wsi);
if (conn_id <= 0) break;
if (len > 0 && in) {
char *buf = malloc(len + 1);
if (buf) {
memcpy(buf, in, len);
buf[len] = '\0';
cJSON *root = cJSON_Parse(buf);
free(buf);
if (root) {
cJSON *type = cJSON_GetObjectItem(root, "type");
cJSON *text = cJSON_GetObjectItem(root, "text");
if (cJSON_IsString(type) && strcmp(type->valuestring, "message") == 0 &&
cJSON_IsString(text) && text->valuestring)
ws_push_incoming(conn_id, text->valuestring);
cJSON_Delete(root);
}
}
char *text = NULL;
int fed;
/* user_space holds the conn id (lws_set_wsi_user), so the
* partial frame lives on the connection table instead. */
if (conn_id <= 0)
break;
fed = ws_conn_rx_feed(conn_id, in, len, lws_is_final_fragment(wsi), &text);

@cursor cursor Bot Nov 11, 2026

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Should fix: ws_conn_rx_feed returns 0 when it needs another spill, when the frame crosses WS_RX_JSON_MAX, when the JSON is rejected, and when conn_id is unknown. This callback then returns 0, so libwebsockets keeps the socket.

skip frees the heap buffer and drops the rest of that message, so memory stays bounded. http_thread_fn is the only lws_service loop, and it still unmasks every later spill. One authenticated client can send a multi-gigabyte frame and stall dashboard HTTP plus every other WebChat socket for the duration of that read.

Return a distinct oversize status and return -1 here so libwebsockets closes the wsi. Leave -1 from ws_rx_acc_feed as OOM: skip already covers the remainder, and a failed realloc should leave the chat socket up.

The default bind is 127.0.0.1 and the upgrade already checks the bearer token. Discord gateway RX uses the same skip-until-final pattern and leaves its socket open. This callback is the process's only service thread, which is the reason to close.

if (fed == 1 && text) {
ws_push_incoming(conn_id, text);
free(text);
}
break;
}
Expand Down
6 changes: 5 additions & 1 deletion src/gateway/http_lws.h
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Original file line number Diff line number Diff line change
Expand Up @@ -25,7 +25,11 @@ extern "C" {
#define CONFIG_BODY_MAX 65536
#define BODY_BUF_SIZE CONFIG_BODY_MAX
#define ASAP_BODY_MAX (1024 * 1024)
/** Per-callback WebChat RX. Must fit `{"type":"message","text":...}` at WS_TEXT_MAX. */
/**
* Per-callback WebChat RX spill (WS_RX_SPILL).
* A legal WS_TEXT_MAX body of quotes or backslashes is larger than this
* on the wire. ws_conn_rx_feed() reassembles until the final fragment.
*/
#define WS_RX_BUFFER_SIZE (WS_TEXT_MAX + 64)

enum http_method {
Expand Down
24 changes: 24 additions & 0 deletions src/gateway/ws.c
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Original file line number Diff line number Diff line change
Expand Up @@ -66,6 +66,7 @@ typedef struct ws_msg {
typedef struct {
ws_conn_t wsi;
int conn_id;
ws_rx_acc_t rx;
} ws_conn_entry_t;

static ws_conn_entry_t g_conns[MAX_CONNECTIONS];
Expand Down Expand Up @@ -138,6 +139,7 @@ int ws_register_conn(int conn_id, ws_conn_t wsi)
pthread_mutex_lock(&g_mutex);
for (int i = 0; i < MAX_CONNECTIONS; i++) {
if (g_conns[i].wsi == NULL) {
ws_rx_acc_free(&g_conns[i].rx);
g_conns[i].wsi = wsi;
g_conns[i].conn_id = conn_id;
registered = 1;
Expand Down Expand Up @@ -227,6 +229,7 @@ void ws_unregister_conn(int conn_id)
pthread_mutex_lock(&g_mutex);
for (i = 0; i < MAX_CONNECTIONS; i++) {
if (g_conns[i].wsi && g_conns[i].conn_id == conn_id) {
ws_rx_acc_free(&g_conns[i].rx);
g_conns[i].wsi = NULL;
g_conns[i].conn_id = 0;
break;
Expand Down Expand Up @@ -442,6 +445,27 @@ void ws_cleanup(void)
g_outgoing_head = NULL;
g_outgoing_tail = NULL;
g_outgoing_count = 0;
for (int i = 0; i < MAX_CONNECTIONS; i++)
ws_rx_acc_free(&g_conns[i].rx);
memset(g_conns, 0, sizeof(g_conns));
pthread_mutex_unlock(&g_mutex);
}

int ws_conn_rx_feed(int conn_id, const void *in, size_t len, int is_final,
char **text_out)
{
int rc = 0;

if (!text_out)
return -1;
*text_out = NULL;
pthread_mutex_lock(&g_mutex);
for (int i = 0; i < MAX_CONNECTIONS; i++) {
if (!g_conns[i].wsi || g_conns[i].conn_id != conn_id)
continue;
rc = ws_rx_acc_feed(&g_conns[i].rx, in, len, is_final, text_out);
break;
}
pthread_mutex_unlock(&g_mutex);
return rc;
}
59 changes: 59 additions & 0 deletions src/gateway/ws.h
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Original file line number Diff line number Diff line change
Expand Up @@ -16,6 +16,19 @@ extern "C" {
#define WS_TEXT_MAX (32 * 1024)
/** C-string dest bytes for a WS_TEXT_MAX payload, including the NUL. */
#define WS_TEXT_BUF_SIZE (WS_TEXT_MAX + 1)
/**
* One libwebsockets receive spill for the ws protocol.
* Not a whole-message cap: JSON escaping can outgrow this.
*/
#define WS_RX_SPILL ((size_t)WS_TEXT_MAX + 64u)
/**
* Largest inbound WebChat JSON object to reassemble.
* JSON.stringify expands one input byte to at most six (`\u00XX`),
* and the `{"type":"message","text":...}` envelope fits in the slack.
*
* Example: a WS_TEXT_MAX string of backslashes is accepted; one byte more is not.
*/
#define WS_RX_JSON_MAX ((size_t)WS_TEXT_MAX * 6u + 64u)

/**
* True when @p len_out bytes fit in a WS_TEXT_MAX on-wire text frame.
Expand Down Expand Up @@ -113,6 +126,52 @@ int ws_has_pending_outgoing(int conn_id);
*/
void ws_on_service_cancel(void);

/**
* In-progress WebChat frame. libwebsockets spills one websocket message
* across several LWS_CALLBACK_RECEIVE calls. The bytes live here until
* lws_is_final_fragment() is true. Zero the struct before the first feed
* and call ws_rx_acc_free() when the connection goes away.
*/
typedef struct ws_rx_acc {
char *buf;
size_t len;
size_t cap;
int skip;
} ws_rx_acc_t;

/** Drop any partial frame held in @p acc. Safe on a zeroed struct. */
void ws_rx_acc_free(ws_rx_acc_t *acc);

/**
* Append one RX chunk. On the final chunk, a complete `type:message`
* whose text fits in WS_TEXT_MAX is returned in @p text_out (malloc'd).
*
* @param acc Accumulator for this connection.
* @param in Chunk bytes. May be NULL only when @p len is 0.
* @param len Chunk length.
* @param is_final Non-zero when this chunk ends the websocket message.
* @param text_out Receives the message text, or NULL when more chunks
* are required or the message was dropped.
* @return 1 when @p text_out is set, 0 when nothing is ready, -1 on OOM.
*
* Example: feed each LWS_CALLBACK_RECEIVE until the return value is 1.
*/
int ws_rx_acc_feed(ws_rx_acc_t *acc, const void *in, size_t len, int is_final,
char **text_out);

/**
* Same as ws_rx_acc_feed() for a registered `conn_id`.
* The accumulator is tracked with the connection, because lws_set_wsi_user()
* stores the conn id in the only per-wsi slot libwebsockets gives us.
*
* @return 1 when @p text_out is set, 0 when nothing is ready or @p conn_id
* is not registered, -1 on OOM.
*
* Example: `ws_conn_rx_feed(conn_id, in, len, lws_is_final_fragment(wsi), &text);`
*/
int ws_conn_rx_feed(int conn_id, const void *in, size_t len, int is_final,
char **text_out);

/**
* Get next connection ID for new connections.
*
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