commit 7971df739ffdf324abc87a7886b901375644807a
parent 88529410e76a5aec3e7b9354d7990eedc7908063
Author: Christian Grothoff <grothoff@gnunet.org>
Date: Tue, 13 May 2025 12:29:15 +0200
add json_echo example
Diffstat:
5 files changed, 382 insertions(+), 8 deletions(-)
diff --git a/configure.ac b/configure.ac
@@ -3231,6 +3231,9 @@ AM_CONDITIONAL([MHD_HAVE_TLS_PLUGIN], [[test "x$have_tlsplugin" = xyes]])
AC_CHECK_HEADERS([zlib.h],[have_zlib=yes],[have_zlib=no], [AC_INCLUDES_DEFAULT])
AM_CONDITIONAL([HAVE_ZLIB], [[test "x$have_zlib" = xyes]])
+AC_CHECK_HEADERS([jansson.h],[have_json=yes],[have_json=no], [AC_INCLUDES_DEFAULT])
+AM_CONDITIONAL([HAVE_JANSSON], [[test "x$have_json" = xyes]])
+
# Check for generic functions
MHD_CHECK_FUNC([random],
[
diff --git a/src/examples2/.gitignore b/src/examples2/.gitignore
@@ -4,4 +4,5 @@
/*_example?
/*example_*[a-z0-9_][a-z0-9_][a-z0-9_]
!*.c
-!*.h
-\ No newline at end of file
+!*.hjson_echo
+json_echo
diff --git a/src/examples2/Makefile.am b/src/examples2/Makefile.am
@@ -32,6 +32,10 @@ if HAVE_POSIX_THREADS
noinst_PROGRAMS += demo
endif
+if HAVE_JANSSON
+ noinst_PROGRAMS += json_echo
+endif
+
if MHD_SUPPORT_AUTH_BASIC
noinst_PROGRAMS += minimal_auth_basic
endif
@@ -42,3 +46,10 @@ endif
demo_CFLAGS = $(AM_CFLAGS) $(PTHREAD_CFLAGS)
demo_LDADD = $(LDADD) $(PTHREAD_LIBS)
+
+
+json_echo_SOURCES = \
+ json_echo.c
+json_echo_LDADD = \
+ $(top_builddir)/src/mhd2/libmicrohttpd2.la \
+ -ljansson
diff --git a/src/examples2/demo.c b/src/examples2/demo.c
@@ -1279,17 +1279,23 @@ main (int argc,
{
struct MHD_Daemon *d;
unsigned int port;
+ char dummy;
if ( (argc != 2) ||
- (1 != sscanf (argv[1], "%u", &port)) ||
+ (1 != sscanf (argv[1],
+ "%u%d",
+ &port,
+ &dummy)) ||
(UINT16_MAX < port) )
{
- fprintf (stderr,
- "Usage: %s PORT\n", argv[0]);
- if (argc != 2)
- port = 8080;
- else
+ if (2 == argc)
+ {
+ fprintf (stderr,
+ "Usage: %s PORT\n",
+ argv[0]);
return 1;
+ }
+ port = 8080;
}
#if ! defined(_WIN32) || defined(__CYGWIN__)
ignore_sigpipe ();
diff --git a/src/examples2/json_echo.c b/src/examples2/json_echo.c
@@ -0,0 +1,354 @@
+/*
+ This file is part of libmicrohttpd
+ Copyright (C) 2025 Christian Grothoff (and other contributing authors)
+
+ This library is free software; you can redistribute it and/or
+ modify it under the terms of the GNU Lesser General Public
+ License as published by the Free Software Foundation; either
+ version 2.1 of the License, or (at your option) any later version.
+
+ This library is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ Lesser General Public License for more details.
+
+ You should have received a copy of the GNU Lesser General Public
+ License along with this library; if not, write to the Free Software
+ Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+*/
+/**
+ * @file json_echo.c
+ * @brief example for processing POST requests with JSON uploads, echos the JSON back to the client
+ * @author Christian Grothoff
+ */
+#include <stdlib.h>
+#include <string.h>
+#include <stdio.h>
+#include <errno.h>
+#include <unistd.h>
+#include <assert.h>
+#define MHD_APP_SOCKET_CNTX_TYPE struct AppSockContext
+#include <microhttpd2.h>
+#include <jansson.h>
+
+/**
+ * Bad request page.
+ */
+#define BAD_REQUEST_PAGE \
+ "<html><head><title>Illegal request</title></head><body>Go away.</body></html>"
+
+/**
+ * Invalid JSON page.
+ */
+#define FILE_NOT_FOUND_PAGE \
+ "<html><head><title>Not found</title></head><body>Go away.</body></html>"
+
+/**
+ * We keep the sockets we are waiting on in a DLL.
+ */
+struct AppSockContext
+{
+ struct AppSockContext *next;
+ struct AppSockContext *prev;
+ struct MHD_EventUpdateContext *ecb_cntx;
+ MHD_Socket fd;
+};
+
+
+/**
+ * Current read set.
+ */
+static fd_set rs;
+
+/**
+ * Current write set.
+ */
+static fd_set ws;
+
+/**
+ * Current error set.
+ */
+static fd_set es;
+
+/**
+ * Maximum FD in any set.
+ */
+static int max_fd;
+
+/**
+ * Head of our internal list of sockets to select() on.
+ */
+static struct AppSockContext *head;
+
+/**
+ * Generates 404.
+ */
+static struct MHD_Response *file_not_found_response;
+
+/**
+ * Generates 400.
+ */
+static struct MHD_Response *bad_request_response;
+
+
+static const struct MHD_UploadAction *
+handle_upload (void *upload_cls,
+ struct MHD_Request *request,
+ size_t content_data_size,
+ void *content_data)
+{
+ json_t *j;
+ json_error_t err;
+ char *s;
+ struct MHD_Response *response;
+
+ j = json_loadb (content_data,
+ content_data_size,
+ 0,
+ &err);
+ if (NULL == j)
+ return MHD_upload_action_from_response (request,
+ bad_request_response);
+ s = json_dumps (j,
+ JSON_INDENT (2));
+ json_decref (j);
+ response = MHD_response_from_buffer (MHD_HTTP_STATUS_OK,
+ strlen (s),
+ s,
+ &free,
+ s);
+ return MHD_upload_action_from_response (request,
+ response);
+}
+
+
+static const struct MHD_Action *
+handle_request (void *cls,
+ struct MHD_Request *request,
+ const struct MHD_String *path,
+ enum MHD_HTTP_Method method,
+ uint_fast64_t upload_size)
+{
+ if (method != MHD_HTTP_METHOD_POST)
+ return MHD_action_from_response (request,
+ file_not_found_response);
+ if (upload_size > 16 * 1024 * 1024)
+ return MHD_action_abort_request (request);
+ return MHD_action_process_upload_full (request,
+ upload_size,
+ &handle_upload,
+ NULL);
+}
+
+
+/* This is the function MHD will call when the external event
+ loop needs to change how it watches out for changes to
+ some socket's state */
+static MHD_APP_SOCKET_CNTX_TYPE *
+sock_reg_update_cb (
+ void *cls,
+ MHD_Socket fd,
+ enum MHD_FdState watch_for,
+ MHD_APP_SOCKET_CNTX_TYPE *app_cntx,
+ struct MHD_EventUpdateContext *ecb_cntx)
+{
+ /* Note: This code only works on UNIX where MHD_Socket is an "int". */
+ if (fd >= FD_SETSIZE)
+ return NULL; /* not allowed by select() */
+ if (MHD_FD_STATE_NONE == watch_for)
+ {
+ /* Remove from DLL */
+ if (app_cntx == head)
+ head = app_cntx->next;
+ if (NULL != app_cntx->prev)
+ app_cntx->prev->next = app_cntx->next;
+ if (NULL != app_cntx->next)
+ app_cntx->next->prev = app_cntx->prev;
+ free (app_cntx);
+ return NULL;
+ }
+ if (NULL == app_cntx)
+ {
+ /* First time, allocate data structure to keep
+ the socket and MHD's context */
+ app_cntx = malloc (sizeof (MHD_APP_SOCKET_CNTX_TYPE));
+ if (NULL == app_cntx)
+ return NULL; /* closes connection */
+ /* prepend to DLL */
+ app_cntx->prev = NULL;
+ app_cntx->next = head;
+ head->prev = app_cntx;
+ head = app_cntx;
+ app_cntx->fd = fd;
+ }
+ else
+ {
+ /* socket must not change */
+ assert (fd == app_cntx->fd);
+ }
+ /* MHD could change its associated context, so always update */
+ app_cntx->ecb_cntx = ecb_cntx;
+ /* Since we are level-triggered and thus called by MHD in every
+ iteration, we simply build the event sets for select()
+ here directly. */
+ if (watch_for & MHD_FD_STATE_RECV)
+ FD_SET (fd,
+ &rs);
+ if (watch_for & MHD_FD_STATE_SEND)
+ FD_SET (fd,
+ &ws);
+ if (watch_for & MHD_FD_STATE_EXCEPT)
+ FD_SET (fd,
+ &es);
+ if (fd > max_fd)
+ max_fd = fd;
+ return app_cntx;
+}
+
+
+/**
+ * Mark the given response as HTML for the browser.
+ *
+ * @param response response to mark
+ */
+static void
+mark_as_html (struct MHD_Response *response)
+{
+ if (NULL == response)
+ return;
+ (void) MHD_response_add_header (response,
+ MHD_HTTP_HEADER_CONTENT_TYPE,
+ "text/html");
+}
+
+
+/**
+ * Call with the port number as the only argument.
+ * Terminates when reading from stdin or on signals, such as CTRL-C.
+ */
+int
+main (int argc,
+ char *const *argv)
+{
+ struct MHD_Daemon *d;
+ struct timeval tv;
+ struct timeval *tvp;
+ fd_set rs;
+ fd_set ws;
+ fd_set es;
+ MHD_Socket max;
+ uint64_t mhd_timeout;
+ unsigned int port;
+ char dummy;
+
+ if ( (argc != 2) ||
+ (1 != sscanf (argv[1],
+ "%u%c",
+ &port,
+ &dummy)) ||
+ (UINT16_MAX < port) )
+ {
+ if (2 == argc)
+ {
+ fprintf (stderr,
+ "Usage: %s PORT\n",
+ argv[0]);
+ return 1;
+ }
+ port = 8080;
+ }
+ file_not_found_response =
+ MHD_response_from_buffer_static (
+ MHD_HTTP_STATUS_NOT_FOUND,
+ strlen (FILE_NOT_FOUND_PAGE),
+ FILE_NOT_FOUND_PAGE);
+ mark_as_html (file_not_found_response);
+ if (MHD_SC_OK !=
+ MHD_response_set_option (file_not_found_response,
+ &MHD_R_OPTION_REUSABLE (MHD_YES)))
+ return 1;
+ bad_request_response =
+ MHD_response_from_buffer_static (
+ MHD_HTTP_STATUS_BAD_REQUEST,
+ strlen (BAD_REQUEST_PAGE),
+ BAD_REQUEST_PAGE);
+ mark_as_html (bad_request_response);
+ if (MHD_SC_OK !=
+ MHD_response_set_option (bad_request_response,
+ &MHD_R_OPTION_REUSABLE (MHD_YES)))
+ return 1;
+
+ d = MHD_daemon_create (&handle_request,
+ NULL);
+ if (NULL == d)
+ return 1;
+ if (MHD_SC_OK !=
+ MHD_DAEMON_SET_OPTIONS (
+ d,
+ MHD_D_OPTION_WM_EXTERNAL_EVENT_LOOP_CB_LEVEL (
+ &sock_reg_update_cb,
+ NULL),
+ MHD_D_OPTION_DEFAULT_TIMEOUT (120 /* seconds */),
+ MHD_D_OPTION_CONN_MEMORY_LIMIT (256 * 1024),
+ MHD_D_OPTION_BIND_PORT (MHD_AF_AUTO,
+ (uint_least16_t) port)))
+ return 1;
+ if (MHD_SC_OK !=
+ MHD_daemon_start (d))
+ {
+ MHD_daemon_destroy (d);
+ return 1;
+ }
+ while (1)
+ {
+ struct timeval ts;
+ struct AppSockContext *pos;
+ uint_fast64_t next_wait;
+
+ FD_ZERO (&rs);
+ FD_ZERO (&ws);
+ FD_ZERO (&es);
+ FD_SET (STDIN_FILENO,
+ &rs);
+ max_fd = STDIN_FILENO;
+ /* This will cause MHD to call the #sock_reg_update_cb() */
+ MHD_daemon_process_reg_events (d,
+ &next_wait);
+ ts.tv_sec = next_wait / 1000000;
+ ts.tv_usec = next_wait % 1000000;
+ /* Real applications may do nicer error handling here */
+ (void) select (max_fd + 1,
+ &rs,
+ &ws,
+ &es,
+ &ts);
+ if (FD_ISSET (STDIN_FILENO,
+ &rs))
+ break; /* exit on input on stdin */
+
+ /* Now we need to tell MHD which events were triggered */
+ for (pos = head; NULL != pos; pos = pos->next)
+ {
+ enum MHD_FdState current_state = MHD_FD_STATE_NONE;
+
+ if (FD_ISSET (pos->fd,
+ &rs))
+ current_state |= MHD_FD_STATE_RECV;
+ if (FD_ISSET (pos->fd,
+ &ws))
+ current_state |= MHD_FD_STATE_SEND;
+ if (FD_ISSET (pos->fd,
+ &es))
+ current_state |= MHD_FD_STATE_EXCEPT;
+ if (MHD_FD_STATE_NONE == current_state)
+ continue; /* not triggered */
+ MHD_daemon_event_update (d,
+ pos->ecb_cntx,
+ current_state);
+ }
+ }
+ MHD_daemon_destroy (d);
+ MHD_response_destroy (file_not_found_response);
+ MHD_response_destroy (bad_request_response);
+ return 0;
+}
