use llhttp for parsing api requests

This commit is contained in:
Arthur Lu 2024-09-03 13:44:06 -07:00
parent 44706c75a1
commit 790262ac1c
4 changed files with 166 additions and 79 deletions

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@ -1,21 +1,33 @@
cmake_minimum_required(VERSION 3.13) cmake_minimum_required(VERSION 3.13)
set(PROGRAM_NAME pico_bmc) set(PROGRAM_NAME pico_bmc)
set(PICO_BOARD pico_w) set(PICO_BOARD pico_w)
include(pico_sdk_import.cmake) include(pico_sdk_import.cmake)
project(pico_bmc) project(pico_bmc)
pico_sdk_init() pico_sdk_init()
include(FetchContent)
FetchContent_Declare(llhttp URL "https://github.com/nodejs/llhttp/archive/refs/tags/release/v9.2.1.tar.gz")
set(BUILD_SHARED_LIBS OFF CACHE INTERNAL "")
set(BUILD_STATIC_LIBS ON CACHE INTERNAL "")
FetchContent_MakeAvailable(llhttp)
add_executable(${PROGRAM_NAME} add_executable(${PROGRAM_NAME}
main.c main.c
) )
target_include_directories(${PROGRAM_NAME} PRIVATE target_include_directories(${PROGRAM_NAME} PRIVATE
${CMAKE_CURRENT_LIST_DIR} ${CMAKE_CURRENT_LIST_DIR}
) )
target_link_libraries(${PROGRAM_NAME} target_link_libraries(${PROGRAM_NAME}
pico_cyw43_arch_lwip_threadsafe_background pico_cyw43_arch_lwip_threadsafe_background
pico_stdlib pico_stdlib
pico_multicore pico_multicore
hardware_adc hardware_adc
llhttp_static
) )
pico_enable_stdio_usb(${PROGRAM_NAME} TRUE) pico_enable_stdio_usb(${PROGRAM_NAME} TRUE)
pico_enable_stdio_uart(${PROGRAM_NAME} FALSE) pico_enable_stdio_uart(${PROGRAM_NAME} FALSE)
pico_add_extra_outputs(${PROGRAM_NAME}) pico_add_extra_outputs(${PROGRAM_NAME})

98
http_parser.h Normal file
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@ -0,0 +1,98 @@
#ifndef HTTP_PARSER_H
#define HTTP_PARSER_H
#include "llhttp.h"
typedef struct HTTP_REQUEST_DATA_T_ {
char protocol[8];
char method[8];
char url[128];
char body[128];
} HTTP_REQUEST_DATA_T;
typedef struct HTTP_REQUEST_PARSER_WRAPPER_T_ {
llhttp_t parser;
llhttp_settings_t settings;
} HTTP_REQUEST_PARSER_WRAPPER_T;
int request_parser_on_url(llhttp_t * parser, const char * start, size_t length) {
HTTP_REQUEST_DATA_T * http_request = parser->data;
strncat(http_request->url, start, length);
return 0;
}
int request_parser_on_body(llhttp_t * parser, const char * start, size_t length) {
HTTP_REQUEST_DATA_T * http_request = parser->data;
strncat(http_request->body, start, length);
return 0;
}
int parse_http_request (HTTP_REQUEST_PARSER_WRAPPER_T * wrapper, char * content, size_t len) {
llhttp_t parser = wrapper->parser;
llhttp_errno_t err = llhttp_execute(&parser, content, len);
HTTP_REQUEST_DATA_T * http_request = parser.data;
uint8_t protocol_major = llhttp_get_http_major(&parser);
uint8_t protocol_minor = llhttp_get_http_minor(&parser);
sprintf(http_request->protocol, "%d.%d", protocol_major, protocol_minor);
uint8_t method = llhttp_get_method(&parser);
const char * method_name = llhttp_method_name(method);
strcpy(http_request->method, method_name);
return 0;
}
char * get_protocol (HTTP_REQUEST_PARSER_WRAPPER_T * wrapper) {
HTTP_REQUEST_DATA_T * http_request = wrapper->parser.data;
return http_request->protocol;
}
char * get_method (HTTP_REQUEST_PARSER_WRAPPER_T * wrapper) {
HTTP_REQUEST_DATA_T * http_request = wrapper->parser.data;
return http_request->method;
}
char * get_url (HTTP_REQUEST_PARSER_WRAPPER_T * wrapper) {
HTTP_REQUEST_DATA_T * http_request = wrapper->parser.data;
return http_request->url;
}
char * get_body (HTTP_REQUEST_PARSER_WRAPPER_T * wrapper) {
HTTP_REQUEST_DATA_T * http_request = wrapper->parser.data;
return http_request->body;
}
HTTP_REQUEST_PARSER_WRAPPER_T * new_request_parser () {
HTTP_REQUEST_PARSER_WRAPPER_T * wrapper = calloc(1, sizeof(HTTP_REQUEST_PARSER_WRAPPER_T));
// create a new request data struct
HTTP_REQUEST_DATA_T * http_request = calloc(1, sizeof(HTTP_REQUEST_DATA_T));
// init http parser settings
llhttp_settings_init(&wrapper->settings);
wrapper->settings.on_url = &request_parser_on_url;
wrapper->settings.on_body = &request_parser_on_body;
// init http request parser parser
llhttp_init(&wrapper->parser, HTTP_REQUEST, &wrapper->settings);
wrapper->parser.data = http_request;
return wrapper;
}
void delete_request_parser (HTTP_REQUEST_PARSER_WRAPPER_T * wrapper) {
free(wrapper->parser.data);
free(wrapper);
}
int http_parser_init () {
return 0;
}
int http_parser_deinit () {
return 0;
}
#endif

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@ -1,9 +1,9 @@
#ifndef HTTP_SERV_H #ifndef HTTP_SERV_H
#define HTTP_SERV_H #define HTTP_SERV_H
#include <string.h>
#include "lwip/pbuf.h" #include "lwip/pbuf.h"
#include "lwip/tcp.h" #include "lwip/tcp.h"
#include "http_parser.h"
#define HTTP_PORT 80 #define HTTP_PORT 80
#define POLL_TIME_S 5 #define POLL_TIME_S 5
@ -22,13 +22,9 @@ typedef struct TCP_SERVER_T_ {
typedef struct TCP_CONNECT_STATE_T_ { typedef struct TCP_CONNECT_STATE_T_ {
struct tcp_pcb * pcb; struct tcp_pcb * pcb;
int sent_len; int sent_len;
char method[8];
char request[128];
char params[128];
char protocol[8];
char headers[1024]; char headers[1024];
char body[128];
char result[128]; char result[128];
HTTP_REQUEST_PARSER_WRAPPER_T * request_parser;
int header_len; int header_len;
int result_len; int result_len;
ip_addr_t * gw; ip_addr_t * gw;
@ -51,8 +47,10 @@ static err_t tcp_close_client_connection(TCP_CONNECT_STATE_T * con_state, struct
close_err = ERR_ABRT; close_err = ERR_ABRT;
} }
if (con_state) { if (con_state) {
delete_request_parser(con_state->request_parser);
free(con_state); free(con_state);
} }
DEBUG_printf("[HTTP] [OK ] Finished and closed connection to client\n");
} }
return close_err; return close_err;
} }
@ -76,64 +74,6 @@ static err_t tcp_server_sent(void * arg, struct tcp_pcb * pcb, u16_t len) {
return ERR_OK; return ERR_OK;
} }
static int handle_status_get (const char * request, const char * params, const char * body, char * result, size_t max_result_len) {
return snprintf(result, max_result_len, "{volt: %f, temp: %f, power: %d}", current_state.voltage, current_state.tempC, current_state.power_state);
}
static int handle_power_post (const char * request, const char * params, const char * body, char * result, size_t max_result_len) {
if (strstr(body, "requested_state")) {
int requested_power_state_int;
int led_param = sscanf(body, "requested_state=%d", &requested_power_state_int);
if (led_param) {
if (requested_power_state_int == 0 || requested_power_state_int == 1) {
bmc_power_handler((bool) requested_power_state_int);
return snprintf(result, max_result_len, "{}");
}
else {
return snprintf(result, max_result_len, "{error: true, description: \"invalid requested state, must be 0 or 1\"}");
}
}
else {
return snprintf(result, max_result_len, "{error: true, description: \"invalid requested state, must be 0 or 1\"}");
}
}
else {
return snprintf(result, max_result_len, "{error: true, description: \"missing required parameter requested_state\"}");
}
}
int parse_content (struct pbuf * p, TCP_CONNECT_STATE_T * con_state) {
char content[2048] = {0};
pbuf_copy_partial(p, &content, 2048 - 1, 0);
char * headers_start = content; // First header line containing method request?params HTTP/protocol
char * headers_other = strstr(content, "\r\n") + 2; // remaining headers follow the first line
char * body_start = strstr(content, "\r\n\r\n") + 4; // body begins at the end of headers
*(headers_other - 2) = 0;
*(body_start - 4) = 0;
char request_params_comb[256];
if (sscanf(headers_start, "%s %s HTTP/%s", con_state->method, request_params_comb, con_state->protocol) != 3) {
return 0;
}
char * params = strchr(request_params_comb, '?');
if (params) {
*params++ = 0;
strcpy(con_state->request, request_params_comb);
strcpy(con_state->params, params);
}
else {
strcpy(con_state->request, request_params_comb);
}
strcpy(con_state->headers, headers_other);
strcpy(con_state->body, body_start);
return 1;
}
int send_response (TCP_CONNECT_STATE_T * con_state, struct tcp_pcb * pcb) { int send_response (TCP_CONNECT_STATE_T * con_state, struct tcp_pcb * pcb) {
// Check result buffer size // Check result buffer size
if (con_state->result_len > sizeof(con_state->result) - 1) { if (con_state->result_len > sizeof(con_state->result) - 1) {
@ -164,6 +104,32 @@ int send_response (TCP_CONNECT_STATE_T * con_state, struct tcp_pcb * pcb) {
return 0; return 0;
} }
static int handle_status_get (const char * request, const char * params, const char * body, char * result, size_t max_result_len) {
return snprintf(result, max_result_len, "{volt: %f, temp: %f, power: %d}", current_state.voltage, current_state.tempC, current_state.power_state);
}
static int handle_power_post (const char * request, const char * params, const char * body, char * result, size_t max_result_len) {
if (strstr(body, "requested_state")) {
int requested_power_state_int;
int led_param = sscanf(body, "requested_state=%d", &requested_power_state_int);
if (led_param) {
if (requested_power_state_int == 0 || requested_power_state_int == 1) {
bmc_power_handler((bool) requested_power_state_int);
return snprintf(result, max_result_len, "{}");
}
else {
return snprintf(result, max_result_len, "{error: true, description: \"invalid requested state, must be 0 or 1\"}");
}
}
else {
return snprintf(result, max_result_len, "{error: true, description: \"invalid requested state, must be 0 or 1\"}");
}
}
else {
return snprintf(result, max_result_len, "{error: true, description: \"missing required parameter requested_state\"}");
}
}
err_t tcp_server_recv(void * arg, struct tcp_pcb * pcb, struct pbuf * p, err_t err) { err_t tcp_server_recv(void * arg, struct tcp_pcb * pcb, struct pbuf * p, err_t err) {
TCP_CONNECT_STATE_T * con_state = (TCP_CONNECT_STATE_T *)arg; TCP_CONNECT_STATE_T * con_state = (TCP_CONNECT_STATE_T *)arg;
if (!p) { if (!p) {
@ -173,40 +139,45 @@ err_t tcp_server_recv(void * arg, struct tcp_pcb * pcb, struct pbuf * p, err_t e
assert(con_state && con_state->pcb == pcb); assert(con_state && con_state->pcb == pcb);
if (p->tot_len > 0) { if (p->tot_len > 0) {
DEBUG_printf("[HTTP] [OK ] Server recieved %d err %d\n", p->tot_len, err); DEBUG_printf("[HTTP] [OK ] Server recieved %d err %d\n", p->tot_len, err);
// Copy the request into the buffer
if (!parse_content(p, con_state)) { char content[2048] = {0};
DEBUG_printf("[HTTP] [ERR] Failed to parse header\n"); pbuf_copy_partial(p, &content, 2048 - 1, 0);
return tcp_close_client_connection(con_state, pcb, ERR_OK); con_state->request_parser = new_request_parser();
} parse_http_request(con_state->request_parser, content, strlen(content));
char * protocol = get_protocol(con_state->request_parser);
char * method = get_method(con_state->request_parser);
char * url = get_url(con_state->request_parser);
char * body = get_body(con_state->request_parser);
// print request // print request
DEBUG_printf("[HTTP] [OK ] Request: %s %s?%s %s\n", con_state->method, con_state->request, con_state->params, con_state->body); DEBUG_printf("[HTTP] [OK ] Request: %s %s %s\n", method, url, body);
int response_code; int response_code;
// parse request depending on method and request // parse request depending on method and request
if (strncmp(con_state->method, HTTP_GET, sizeof(HTTP_GET) - 1) == 0 && strncmp(con_state->request, "/status", sizeof("/status") - 1) == 0) { if (strncmp(method, HTTP_GET, sizeof(HTTP_GET) - 1) == 0 && strncmp(url, "/status", sizeof("/status") - 1) == 0) {
con_state->result_len = handle_status_get(con_state->request, con_state->params, con_state->body, con_state->result, sizeof(con_state->result)); con_state->result_len = handle_status_get(url, NULL, body, con_state->result, sizeof(con_state->result));
response_code = 200; response_code = 200;
con_state->header_len = snprintf(con_state->headers, sizeof(con_state->headers), HTTP_RESPONSE_HEADER, response_code, con_state->result_len); con_state->header_len = snprintf(con_state->headers, sizeof(con_state->headers), HTTP_RESPONSE_HEADER, response_code, con_state->result_len);
} }
else if (strncmp(con_state->method, HTTP_POST, sizeof(HTTP_POST) - 1) == 0 && strncmp(con_state->request, "/power", sizeof("/power") - 1) == 0) { else if (strncmp(method, HTTP_POST, sizeof(HTTP_POST) - 1) == 0 && strncmp(url, "/power", sizeof("/power") - 1) == 0) {
con_state->result_len = handle_power_post(con_state->request, con_state->params, con_state->body, con_state->result, sizeof(con_state->result)); con_state->result_len = handle_power_post(url, NULL, body, con_state->result, sizeof(con_state->result));
response_code = 200; response_code = 200;
con_state->header_len = snprintf(con_state->headers, sizeof(con_state->headers), HTTP_RESPONSE_HEADER, response_code, con_state->result_len); con_state->header_len = snprintf(con_state->headers, sizeof(con_state->headers), HTTP_RESPONSE_HEADER, response_code, con_state->result_len);
} }
else { else { // if not a registered path, return HTTP 404
con_state->result_len = 0; con_state->result_len = 0;
response_code = 501; response_code = 404;
con_state->header_len = snprintf(con_state->headers, sizeof(con_state->headers), HTTP_RESPONSE_HEADER, response_code, con_state->result_len); con_state->header_len = snprintf(con_state->headers, sizeof(con_state->headers), HTTP_RESPONSE_HEADER, response_code, con_state->result_len);
} }
// print result // print result
DEBUG_printf("[HTTP] [OK ] Result: %d %s\n", response_code, con_state->result); DEBUG_printf("[HTTP] [OK ] Result: %d %s\n", response_code, con_state->result);
if (send_response(con_state, pcb)) { int err;
DEBUG_printf("[HTTP] [ERR] Failure in send\n"); if (err = send_response(con_state, pcb)) {
DEBUG_printf("[HTTP] [ERR] Failure in send %d\n", err);
} }
tcp_recved(pcb, p->tot_len); tcp_recved(pcb, p->tot_len);
@ -287,6 +258,11 @@ static bool tcp_server_open(void * arg) {
} }
int http_serv_init () { int http_serv_init () {
// init http parser
if (http_parser_init()) {
DEBUG_printf("[HTTP] [ERR] Failed to initialize http parser\n");
}
http_serv_state = calloc(1, sizeof(TCP_SERVER_T)); http_serv_state = calloc(1, sizeof(TCP_SERVER_T));
if (!http_serv_state) { if (!http_serv_state) {
DEBUG_printf("[HTTP] [ERR] Failed to allocate state\n"); DEBUG_printf("[HTTP] [ERR] Failed to allocate state\n");
@ -304,6 +280,7 @@ int http_serv_init () {
} }
int http_serv_deinit () { int http_serv_deinit () {
http_parser_deinit();
tcp_server_close(http_serv_state); tcp_server_close(http_serv_state);
free(http_serv_state); free(http_serv_state);
http_serv_state = NULL; http_serv_state = NULL;

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@ -9,7 +9,7 @@ void set_host_name(const char * hostname) {
cyw43_arch_lwip_end(); cyw43_arch_lwip_end();
} }
int network_init (char * hostname, char * wifi_ssid, char * wifi_pass) { int network_init (const char * hostname, const char * wifi_ssid, const char * wifi_pass) {
set_host_name(hostname); set_host_name(hostname);
DEBUG_printf("[INIT] [OK ] Set hostname to %s\n", BMC_HOSTNAME); DEBUG_printf("[INIT] [OK ] Set hostname to %s\n", BMC_HOSTNAME);