esp-idf/components/esp_http_server/src/httpd_sess.c
2022-12-29 18:08:38 +05:30

493 lines
13 KiB
C

/*
* SPDX-FileCopyrightText: 2018-2021 Espressif Systems (Shanghai) CO LTD
*
* SPDX-License-Identifier: Apache-2.0
*/
#include <stdlib.h>
#include <esp_log.h>
#include <esp_err.h>
#include <fcntl.h>
#include <errno.h>
#include <unistd.h>
#include <esp_http_server.h>
#include "esp_httpd_priv.h"
static const char *TAG = "httpd_sess";
typedef enum {
HTTPD_TASK_NONE = 0,
HTTPD_TASK_INIT, // Init session
HTTPD_TASK_GET_ACTIVE, // Get active session (fd!=-1)
HTTPD_TASK_GET_FREE, // Get free session slot (fd<0)
HTTPD_TASK_FIND_FD, // Find session with specific fd
HTTPD_TASK_SET_DESCRIPTOR, // Set descriptor
HTTPD_TASK_DELETE_INVALID, // Delete invalid session
HTTPD_TASK_FIND_LOWEST_LRU, // Find session with lowest lru
HTTPD_TASK_CLOSE // Close session
} task_t;
typedef struct {
task_t task;
int fd;
fd_set *fdset;
int max_fd;
struct httpd_data *hd;
uint64_t lru_counter;
struct sock_db *session;
} enum_context_t;
void httpd_sess_enum(struct httpd_data *hd, httpd_session_enum_function enum_function, void *context)
{
if ((!hd) || (!hd->hd_sd) || (!hd->config.max_open_sockets)) {
return;
}
struct sock_db *current = hd->hd_sd;
struct sock_db *end = hd->hd_sd + hd->config.max_open_sockets - 1;
while (current <= end) {
if (enum_function && (!enum_function(current, context))) {
break;
}
current++;
}
}
// Check if a FD is valid
static int fd_is_valid(int fd)
{
return fcntl(fd, F_GETFD) != -1 || errno != EBADF;
}
static int enum_function(struct sock_db *session, void *context)
{
if ((!session) || (!context)) {
return 0;
}
enum_context_t *ctx = (enum_context_t *) context;
int found = 0;
switch (ctx->task) {
// Initialize session
case HTTPD_TASK_INIT:
session->fd = -1;
session->ctx = NULL;
break;
// Get active session
case HTTPD_TASK_GET_ACTIVE:
found = (session->fd != -1);
break;
// Get free slot
case HTTPD_TASK_GET_FREE:
found = (session->fd < 0);
break;
// Find fd
case HTTPD_TASK_FIND_FD:
found = (session->fd == ctx->fd);
break;
// Set descriptor
case HTTPD_TASK_SET_DESCRIPTOR:
if (session->fd != -1) {
FD_SET(session->fd, ctx->fdset);
if (session->fd > ctx->max_fd) {
ctx->max_fd = session->fd;
}
}
break;
// Delete invalid session
case HTTPD_TASK_DELETE_INVALID:
if (!fd_is_valid(session->fd)) {
ESP_LOGW(TAG, LOG_FMT("Closing invalid socket %d"), session->fd);
httpd_sess_delete(ctx->hd, session);
}
break;
// Find lowest lru
case HTTPD_TASK_FIND_LOWEST_LRU:
// Found free slot - no need to check other sessions
if (session->fd == -1) {
return 0;
}
// Check/update lowest lru
if (session->lru_counter < ctx->lru_counter) {
ctx->lru_counter = session->lru_counter;
ctx->session = session;
}
break;
case HTTPD_TASK_CLOSE:
if (session->fd != -1) {
ESP_LOGD(TAG, LOG_FMT("cleaning up socket %d"), session->fd);
httpd_sess_delete(ctx->hd, session);
}
break;
default:
return 0;
}
if (found) {
ctx->session = session;
return 0;
}
return 1;
}
static void httpd_sess_close(void *arg)
{
struct sock_db *sock_db = (struct sock_db *) arg;
if (!sock_db) {
return;
}
if (!sock_db->lru_counter && !sock_db->lru_socket) {
ESP_LOGD(TAG, "Skipping session close for %d as it seems to be a race condition", sock_db->fd);
return;
}
sock_db->lru_socket = false;
struct httpd_data *hd = (struct httpd_data *) sock_db->handle;
httpd_sess_delete(hd, sock_db);
}
struct sock_db *httpd_sess_get_free(struct httpd_data *hd)
{
if ((!hd) || (hd->hd_sd_active_count == hd->config.max_open_sockets)) {
return NULL;
}
enum_context_t context = {
.task = HTTPD_TASK_GET_FREE
};
httpd_sess_enum(hd, enum_function, &context);
return context.session;
}
bool httpd_is_sess_available(struct httpd_data *hd)
{
return httpd_sess_get_free(hd) ? true : false;
}
struct sock_db *httpd_sess_get(struct httpd_data *hd, int sockfd)
{
if ((!hd) || (!hd->hd_sd) || (!hd->config.max_open_sockets)) {
return NULL;
}
// Check if called inside a request handler, and the session sockfd in use is same as the parameter
// => Just return the pointer to the sock_db corresponding to the request
if ((hd->hd_req_aux.sd) && (hd->hd_req_aux.sd->fd == sockfd)) {
return hd->hd_req_aux.sd;
}
enum_context_t context = {
.task = HTTPD_TASK_FIND_FD,
.fd = sockfd
};
httpd_sess_enum(hd, enum_function, &context);
return context.session;
}
esp_err_t httpd_sess_new(struct httpd_data *hd, int newfd)
{
ESP_LOGD(TAG, LOG_FMT("fd = %d"), newfd);
if (httpd_sess_get(hd, newfd)) {
ESP_LOGE(TAG, LOG_FMT("session already exists with fd = %d"), newfd);
return ESP_FAIL;
}
struct sock_db *session = httpd_sess_get_free(hd);
if (!session) {
ESP_LOGD(TAG, LOG_FMT("unable to launch session for fd = %d"), newfd);
return ESP_FAIL;
}
// Clear session data
memset(session, 0, sizeof (struct sock_db));
session->fd = newfd;
session->handle = (httpd_handle_t) hd;
session->send_fn = httpd_default_send;
session->recv_fn = httpd_default_recv;
// Call user-defined session opening function
if (hd->config.open_fn) {
esp_err_t ret = hd->config.open_fn(hd, session->fd);
if (ret != ESP_OK) {
httpd_sess_delete(hd, session);
ESP_LOGD(TAG, LOG_FMT("open_fn failed for fd = %d"), newfd);
return ret;
}
}
// increment number of sessions
hd->hd_sd_active_count++;
ESP_LOGD(TAG, LOG_FMT("active sockets: %d"), hd->hd_sd_active_count);
return ESP_OK;
}
void httpd_sess_free_ctx(void **ctx, httpd_free_ctx_fn_t free_fn)
{
if ((!ctx) || (!*ctx)) {
return;
}
if (free_fn) {
free_fn(*ctx);
} else {
free(*ctx);
}
*ctx = NULL;
}
void httpd_sess_clear_ctx(struct sock_db *session)
{
if ((!session) || ((!session->ctx) && (!session->transport_ctx))) {
return;
}
// free user ctx
if (session->ctx) {
httpd_sess_free_ctx(&session->ctx, session->free_ctx);
session->free_ctx = NULL;
}
// Free 'transport' context
if (session->transport_ctx) {
httpd_sess_free_ctx(&session->transport_ctx, session->free_transport_ctx);
session->free_transport_ctx = NULL;
}
}
void *httpd_sess_get_ctx(httpd_handle_t handle, int sockfd)
{
struct sock_db *session = httpd_sess_get(handle, sockfd);
if (!session) {
return NULL;
}
// Check if the function has been called from inside a
// request handler, in which case fetch the context from
// the httpd_req_t structure
struct httpd_data *hd = (struct httpd_data *) handle;
if (hd->hd_req_aux.sd == session) {
return hd->hd_req.sess_ctx;
}
return session->ctx;
}
void httpd_sess_set_ctx(httpd_handle_t handle, int sockfd, void *ctx, httpd_free_ctx_fn_t free_fn)
{
struct sock_db *session = httpd_sess_get(handle, sockfd);
if (!session) {
return;
}
// Check if the function has been called from inside a
// request handler, in which case set the context inside
// the httpd_req_t structure
struct httpd_data *hd = (struct httpd_data *) handle;
if (hd->hd_req_aux.sd == session) {
if (hd->hd_req.sess_ctx != ctx) {
// Don't free previous context if it is in sockdb
// as it will be freed inside httpd_req_cleanup()
if (session->ctx != hd->hd_req.sess_ctx) {
httpd_sess_free_ctx(&hd->hd_req.sess_ctx, hd->hd_req.free_ctx); // Free previous context
}
hd->hd_req.sess_ctx = ctx;
}
hd->hd_req.free_ctx = free_fn;
return;
}
// Else set the context inside the sock_db structure
if (session->ctx != ctx) {
// Free previous context
httpd_sess_free_ctx(&session->ctx, session->free_ctx);
session->ctx = ctx;
}
session->free_ctx = free_fn;
}
void *httpd_sess_get_transport_ctx(httpd_handle_t handle, int sockfd)
{
struct sock_db *session = httpd_sess_get(handle, sockfd);
return session ? session->transport_ctx : NULL;
}
void httpd_sess_set_transport_ctx(httpd_handle_t handle, int sockfd, void *ctx, httpd_free_ctx_fn_t free_fn)
{
struct sock_db *session = httpd_sess_get(handle, sockfd);
if (!session) {
return;
}
if (session->transport_ctx != ctx) {
// Free previous transport context
httpd_sess_free_ctx(&session->transport_ctx, session->free_transport_ctx);
session->transport_ctx = ctx;
}
session->free_transport_ctx = free_fn;
}
void httpd_sess_set_descriptors(struct httpd_data *hd, fd_set *fdset, int *maxfd)
{
enum_context_t context = {
.task = HTTPD_TASK_SET_DESCRIPTOR,
.max_fd = -1,
.fdset = fdset
};
httpd_sess_enum(hd, enum_function, &context);
if (maxfd) {
*maxfd = context.max_fd;
}
}
void httpd_sess_delete_invalid(struct httpd_data *hd)
{
enum_context_t context = {
.task = HTTPD_TASK_DELETE_INVALID,
.hd = hd
};
httpd_sess_enum(hd, enum_function, &context);
}
void httpd_sess_delete(struct httpd_data *hd, struct sock_db *session)
{
if ((!hd) || (!session) || (session->fd < 0)) {
return;
}
ESP_LOGD(TAG, LOG_FMT("fd = %d"), session->fd);
if (hd->config.enable_so_linger) {
struct linger so_linger = {
.l_onoff = true,
.l_linger = hd->config.linger_timeout,
};
setsockopt(session->fd, SOL_SOCKET, SO_LINGER, &so_linger, sizeof(struct linger));
}
// Call close function if defined
if (hd->config.close_fn) {
hd->config.close_fn(hd, session->fd);
} else {
close(session->fd);
}
esp_http_server_dispatch_event(HTTP_SERVER_EVENT_DISCONNECTED, &session->fd, sizeof(int));
// clear all contexts
httpd_sess_clear_ctx(session);
// mark session slot as available
session->fd = -1;
// decrement number of sessions
hd->hd_sd_active_count--;
ESP_LOGD(TAG, LOG_FMT("active sockets: %d"), hd->hd_sd_active_count);
if (!hd->hd_sd_active_count) {
hd->lru_counter = 0;
}
}
void httpd_sess_init(struct httpd_data *hd)
{
enum_context_t context = {
.task = HTTPD_TASK_INIT
};
httpd_sess_enum(hd, enum_function, &context);
}
bool httpd_sess_pending(struct httpd_data *hd, struct sock_db *session)
{
if (!session) {
return false;
}
if (session->pending_fn) {
// test if there's any data to be read (besides read() function, which is handled by select() in the main httpd loop)
// this should check e.g. for the SSL data buffer
if (session->pending_fn(hd, session->fd) > 0) {
return true;
}
}
return (session->pending_len != 0);
}
/* This MUST return ESP_OK on successful execution. If any other
* value is returned, everything related to this socket will be
* cleaned up and the socket will be closed.
*/
esp_err_t httpd_sess_process(struct httpd_data *hd, struct sock_db *session)
{
if ((!hd) || (!session)) {
return ESP_FAIL;
}
ESP_LOGD(TAG, LOG_FMT("httpd_req_new"));
if (httpd_req_new(hd, session) != ESP_OK) {
return ESP_FAIL;
}
ESP_LOGD(TAG, LOG_FMT("httpd_req_delete"));
if (httpd_req_delete(hd) != ESP_OK) {
return ESP_FAIL;
}
ESP_LOGD(TAG, LOG_FMT("success"));
session->lru_counter = ++hd->lru_counter;
return ESP_OK;
}
esp_err_t httpd_sess_update_lru_counter(httpd_handle_t handle, int sockfd)
{
if (handle == NULL) {
return ESP_ERR_INVALID_ARG;
}
struct httpd_data *hd = (struct httpd_data *) handle;
enum_context_t context = {
.task = HTTPD_TASK_FIND_FD,
.fd = sockfd
};
httpd_sess_enum(hd, enum_function, &context);
if (context.session) {
context.session->lru_counter = ++hd->lru_counter;
return ESP_OK;
}
return ESP_ERR_NOT_FOUND;
}
esp_err_t httpd_sess_close_lru(struct httpd_data *hd)
{
enum_context_t context = {
.task = HTTPD_TASK_FIND_LOWEST_LRU,
.lru_counter = UINT64_MAX,
.fd = -1
};
httpd_sess_enum(hd, enum_function, &context);
if (!context.session) {
return ESP_OK;
}
ESP_LOGD(TAG, LOG_FMT("Closing session with fd %d"), context.session->fd);
context.session->lru_socket = true;
return httpd_sess_trigger_close_(hd, context.session);
}
esp_err_t httpd_sess_trigger_close_(httpd_handle_t handle, struct sock_db *session)
{
if (!session) {
return ESP_ERR_NOT_FOUND;
}
return httpd_queue_work(handle, httpd_sess_close, session);
}
esp_err_t httpd_sess_trigger_close(httpd_handle_t handle, int sockfd)
{
struct sock_db *session = httpd_sess_get(handle, sockfd);
if (!session) {
return ESP_ERR_NOT_FOUND;
}
return httpd_sess_trigger_close_(handle, session);
}
void httpd_sess_close_all(struct httpd_data *hd)
{
enum_context_t context = {
.task = HTTPD_TASK_CLOSE,
.hd = hd
};
httpd_sess_enum(hd, enum_function, &context);
}