feat(http_server): Added API to get scratch buffer data

1. Added the API in esp_http_server to get the raw headers data
from the scratch buffer.
2. This data will be unparsed.

Closes #15857

Author: hrushikesh430

components/esp_http_server/include/esp_http_server.h

@@ -1813,6 +1813,44 @@ esp_err_t httpd_ws_send_data_async(httpd_handle_t handle, int socket, httpd_ws_f
  * @}
  */
 
+/**
+ * @brief Get the length of the raw request data received from the client.
+ *
+ * @param[in] req     Current request
+ * @return
+ *  - 0      : If req is NULL
+ *  - size_t : The length of the buffer containing raw HTTP request data
+ */
+size_t httpd_get_raw_req_data_len(httpd_req_t *req);
+
+/**
+ * @brief Get the raw HTTP request data received from the client.
+ *
+ *        NOTE - This function returns different data for different http server states.
+ * 1. HTTP_SERVER_EVENT_ON_CONNECTED - Returns the data containing information related to URI and headers.
+ * 2. HTTP_SERVER_EVENT_ON_HEADER - Returns the data containing information related to only headers.
+ * 3. HTTP_SERVER_EVENT_ON_DATA - Returns the data containing information related to only headers.
+ * 4. HTTP_SERVER_EVENT_SENT_DATA - Returns the data containing information related to only headers.
+ * 5. HTTP_SERVER_EVENT_DISCONNECTED - Returns the data containing information related to only headers.
+ * 6. HTTP_SERVER_EVENT_STOP - Returns the data containing information related to only headers.
+ *
+ * @param[in] req     Current request
+ * @param[out] buf    Buffer to store the raw request data
+ * @param[in] buf_len The length of the buffer.
+ * @return
+ *  - ESP_OK                : On successful copy of raw request data
+ *  - ESP_ERR_INVALID_ARG   : If req or buf is NULL, or buf_len is 0
+ */
+esp_err_t httpd_get_raw_req_data(httpd_req_t *req, char *buf, size_t buf_len);
+
+/**
+ * @brief Get the HTTPD server state
+ *
+ * @param[in] handle    Handle to server returned by httpd_start
+ * @return HTTPD server state
+ */
+esp_http_server_event_id_t httpd_get_server_state(httpd_handle_t handle);
+
 #ifdef __cplusplus
 }
 #endif

components/esp_http_server/src/esp_httpd_priv.h

@@ -127,6 +127,7 @@ struct httpd_data {
     struct httpd_req hd_req;                /*!< The current HTTPD request */
     struct httpd_req_aux hd_req_aux;        /*!< Additional data about the HTTPD request kept unexposed */
     uint64_t lru_counter;                   /*!< LRU counter */
+    esp_http_server_event_id_t http_server_state;              /*!< HTTPD server state */
 
     /* Array of registered error handler functions */
     httpd_err_handler_func_t *err_handler_fns;

components/esp_http_server/src/httpd_main.c

@@ -1,5 +1,5 @@
 /*
- * SPDX-FileCopyrightText: 2018-2023 Espressif Systems (Shanghai) CO LTD
+ * SPDX-FileCopyrightText: 2018-2025 Espressif Systems (Shanghai) CO LTD
  *
  * SPDX-License-Identifier: Apache-2.0
  */
@@ -126,6 +126,7 @@ static esp_err_t httpd_accept_conn(struct httpd_data *hd, int listen_fd)
         goto exit;
     }
     ESP_LOGD(TAG, LOG_FMT("complete"));
+    hd->http_server_state = HTTP_SERVER_EVENT_ON_CONNECTED;
     esp_http_server_dispatch_event(HTTP_SERVER_EVENT_ON_CONNECTED, &new_fd, sizeof(int));
     return ESP_OK;
 exit:
@@ -539,6 +540,7 @@ esp_err_t httpd_start(httpd_handle_t *handle, const httpd_config_t *config)
     }
 
     *handle = (httpd_handle_t)hd;
+    hd->http_server_state = HTTP_SERVER_EVENT_START;
     esp_http_server_dispatch_event(HTTP_SERVER_EVENT_START, NULL, 0);
 
     return ESP_OK;
@@ -593,3 +595,12 @@ esp_err_t httpd_stop(httpd_handle_t handle)
     esp_http_server_dispatch_event(HTTP_SERVER_EVENT_STOP, NULL, 0);
     return ESP_OK;
 }
+
+esp_http_server_event_id_t httpd_get_server_state(httpd_handle_t handle)
+{
+    struct httpd_data *hd = (struct httpd_data *) handle;
+    if (hd == NULL) {
+        return HTTP_SERVER_EVENT_ERROR;
+    }
+    return hd->http_server_state;
+}

components/esp_http_server/src/httpd_parse.c

@@ -408,6 +408,8 @@ static esp_err_t cb_headers_complete(http_parser *parser)
 
     parser_data->status = PARSING_BODY;
     ra->remaining_len = r->content_len;
+    struct httpd_data *hd = (struct httpd_data *) r->handle;
+    hd->http_server_state = HTTP_SERVER_EVENT_ON_HEADER;
     esp_http_server_dispatch_event(HTTP_SERVER_EVENT_ON_HEADER, &(ra->sd->fd), sizeof(int));
     return ESP_OK;
 }
@@ -1209,3 +1211,44 @@ esp_err_t httpd_req_get_cookie_val(httpd_req_t *req, const char *cookie_name, ch
     return ret;
 
 }
+
+/* Get the length of the raw request data received from the client.
+ */
+size_t httpd_get_raw_req_data_len(httpd_req_t *req)
+{
+    if (req == NULL) {
+        return 0;
+    }
+    struct httpd_req_aux *ra = req->aux;
+    return ra->scratch_cur_size;
+}
+
+/* Get the raw request data, which contains the raw HTTP request headers and
+ * URI related information. Internally, the httpd_parse.c file uses a scratch buffer
+ * to store the original HTTP request data exactly as received from the client.
+ * This function returns the contents of this scratch buffer.
+ *
+ * NOTE - This function returns different data for different http server states.
+ * 1. HTTP_SERVER_EVENT_ON_CONNECTED - Returns the data containing information related to URI and headers.
+ * 2. HTTP_SERVER_EVENT_ON_HEADER - Returns the data containing information related to only headers.
+ * 3. HTTP_SERVER_EVENT_ON_DATA - Returns the data containing information related to only headers.
+ * 4. HTTP_SERVER_EVENT_SENT_DATA - Returns the data containing information related to only headers.
+ * 5. HTTP_SERVER_EVENT_DISCONNECTED - Returns the data containing information related to only headers.
+ * 6. HTTP_SERVER_EVENT_STOP - Returns the data containing information related to only headers.
+ */
+esp_err_t httpd_get_raw_req_data(httpd_req_t *req, char *buf, size_t buf_len)
+{
+    if (req == NULL || buf == NULL) {
+        return ESP_ERR_INVALID_ARG;
+    }
+    if (buf_len == 0) {
+        return ESP_ERR_INVALID_ARG;
+    }
+    if (req->aux == NULL) {
+        ESP_LOGW(TAG, "Request auxiliary data is NULL for URI: [%s]", req->uri ? req->uri : "(null)");
+        return ESP_ERR_INVALID_ARG;
+    }
+    struct httpd_req_aux *ra = req->aux;
+    memcpy(buf, ra->scratch, buf_len);
+    return ESP_OK;
+}

components/esp_http_server/src/httpd_sess.c

@@ -146,6 +146,7 @@ static void httpd_sess_close(void *arg)
     }
     sock_db->lru_socket = false;
     struct httpd_data *hd = (struct httpd_data *) sock_db->handle;
+    hd->http_server_state = HTTP_SERVER_EVENT_DISCONNECTED;
     httpd_sess_delete(hd, sock_db);
 }
 
@@ -374,6 +375,7 @@ void httpd_sess_delete(struct httpd_data *hd, struct sock_db *session)
     } else {
         close(session->fd);
     }
+    hd->http_server_state = HTTP_SERVER_EVENT_DISCONNECTED;
     esp_http_server_dispatch_event(HTTP_SERVER_EVENT_DISCONNECTED, &session->fd, sizeof(int));
 
     // clear all contexts

components/esp_http_server/src/httpd_txrx.c

@@ -294,6 +294,8 @@ esp_err_t httpd_resp_send(httpd_req_t *r, const char *buf, ssize_t buf_len)
     if (httpd_send_all(r, cr_lf_seperator, strlen(cr_lf_seperator)) != ESP_OK) {
         return ESP_ERR_HTTPD_RESP_SEND;
     }
+    struct httpd_data *hd = (struct httpd_data *) r->handle;
+    hd->http_server_state = HTTP_SERVER_EVENT_HEADERS_SENT;
     esp_http_server_dispatch_event(HTTP_SERVER_EVENT_HEADERS_SENT, &(ra->sd->fd), sizeof(int));
 
     /* Sending content */
@@ -306,6 +308,7 @@ esp_err_t httpd_resp_send(httpd_req_t *r, const char *buf, ssize_t buf_len)
         .fd = ra->sd->fd,
         .data_len = buf_len,
     };
+    hd->http_server_state = HTTP_SERVER_EVENT_SENT_DATA;
     esp_http_server_dispatch_event(HTTP_SERVER_EVENT_SENT_DATA, &evt_data, sizeof(esp_http_server_event_data));
     return ESP_OK;
 }
@@ -325,6 +328,7 @@ esp_err_t httpd_resp_send_chunk(httpd_req_t *r, const char *buf, ssize_t buf_len
     }
 
     struct httpd_req_aux *ra = r->aux;
+    struct httpd_data *hd = (struct httpd_data *) r->handle;
     const char *httpd_chunked_hdr_str = "HTTP/1.1 %s\r\nContent-Type: %s\r\nTransfer-Encoding: chunked\r\n";
     const char *colon_separator = ": ";
     const char *cr_lf_seperator = "\r\n";
@@ -404,6 +408,7 @@ esp_err_t httpd_resp_send_chunk(httpd_req_t *r, const char *buf, ssize_t buf_len
         .fd = ra->sd->fd,
         .data_len = buf_len,
     };
+    hd->http_server_state = HTTP_SERVER_EVENT_SENT_DATA;
     esp_http_server_dispatch_event(HTTP_SERVER_EVENT_SENT_DATA, &evt_data, sizeof(esp_http_server_event_data));
 
     return ESP_OK;
@@ -613,6 +618,8 @@ int httpd_req_recv(httpd_req_t *r, char *buf, size_t buf_len)
     }
     ra->remaining_len -= ret;
     ESP_LOGD(TAG, LOG_FMT("received length = %d"), ret);
+    struct httpd_data *hd = (struct httpd_data *) r->handle;
+    hd->http_server_state = HTTP_SERVER_EVENT_ON_DATA;
     esp_http_server_event_data evt_data = {
         .fd = ra->sd->fd,
         .data_len = ret,