gcoap/fileserver: add event callbacks

examples/gcoap_fileserver/Makefile

@@ -21,6 +21,7 @@ USEMODULE += shell_commands
 
 # enable the fileserver module
 USEMODULE += gcoap_fileserver
+USEMODULE += gcoap_fileserver_callback
 USEMODULE += gcoap_fileserver_delete
 USEMODULE += gcoap_fileserver_put
 

examples/gcoap_fileserver/main.c

@@ -17,6 +17,7 @@
  * @}
  */
 
+#include <stdio.h>
 #include "kernel_defines.h"
 #include "net/gcoap.h"
 #include "net/gcoap/fileserver.h"
@@ -45,11 +46,36 @@ static gcoap_listener_t _listener = {
  .resources_len = ARRAY_SIZE(_resources),
 };
 
+static void _event_cb(gcoap_fileserver_event_t event, gcoap_fileserver_event_ctx_t *ctx)
+{
+ switch (event) {
+ case GCOAP_FILESERVER_GET_FILE_START:
+ printf("gcoap fileserver: Download started: %s\n", ctx->path);
+ break;
+ case GCOAP_FILESERVER_GET_FILE_END:
+ printf("gcoap fileserver: Download finished: %s\n", ctx->path);
+ break;
+ case GCOAP_FILESERVER_PUT_FILE_START:
+ printf("gcoap fileserver: Upload started: %s\n", ctx->path);
+ break;
+ case GCOAP_FILESERVER_PUT_FILE_END:
+ printf("gcoap fileserver: Upload finished: %s\n", ctx->path);
+ break;
+ case GCOAP_FILESERVER_DELETE_FILE:
+ printf("gcoap fileserver: Delete %s\n", ctx->path);
+ break;
+ }
+}
+
 int main(void)
 {
  msg_init_queue(_main_msg_queue, MAIN_QUEUE_SIZE);
  gcoap_register_listener(&_listener);
 
+ if (IS_USED(MODULE_GCOAP_FILESERVER_CALLBACK)) {
+ gcoap_fileserver_set_event_cb(_event_cb, NULL);
+ }
+
  char line_buf[SHELL_DEFAULT_BUFSIZE];
  shell_run(NULL, line_buf, SHELL_DEFAULT_BUFSIZE);
 

makefiles/pseudomodules.inc.mk

@@ -67,6 +67,7 @@ PSEUDOMODULES += fatfs_vfs_format
 PSEUDOMODULES += fmt_%
 PSEUDOMODULES += gcoap_forward_proxy
 PSEUDOMODULES += gcoap_fileserver
+PSEUDOMODULES += gcoap_fileserver_callback
 PSEUDOMODULES += gcoap_fileserver_delete
 PSEUDOMODULES += gcoap_fileserver_put
 PSEUDOMODULES += gcoap_dtls

sys/include/net/gcoap/fileserver.h

@@ -90,6 +90,51 @@ extern "C" {
  */
 #define COAPFILESERVER_DIR_DELETE_ETAG (0x6ce88b56u)
 
+/**
+ * @brief GCoAP fileserver event types
+ *
+ * @note This requires the gcoap_fileserver_callback module.
+ */
+typedef enum {
+ GCOAP_FILESERVER_GET_FILE_START, /**< file download started */
+ GCOAP_FILESERVER_GET_FILE_END, /**< file download finished */
+ GCOAP_FILESERVER_PUT_FILE_START, /**< file upload started */
+ GCOAP_FILESERVER_PUT_FILE_END, /**< file upload finished */
+ GCOAP_FILESERVER_DELETE_FILE, /**< file deletion requested
+ (called before file is deleted) */
+} gcoap_fileserver_event_t;
+
+/**
+ * @brief GCoAP fileserver event context
+ */
+typedef struct {
+ const char *path; /**< VFS path of the affected file */
+ void *user_ctx; /**< Optional user supplied context */
+} gcoap_fileserver_event_ctx_t;
+
+/**
+ * @brief GCoAP fileserver event callback type
+ *
+ * @param[in] event Type of the event
+ * @param[in] ctx Event context information
+ *
+ */
+typedef void (*gcoap_fileserver_event_handler_t)(gcoap_fileserver_event_t event,
+ gcoap_fileserver_event_ctx_t *ctx);
+
+/**
+ * @brief Register a consumer for GCoAP fileserver events
+ * Requires the `gcoap_fileserver_callback` module
+ *
+ * The Callback is called on each fileserver event and executed
+ * within the GCoAP thread.
+ *
+ * @param[in] cb The callback function to be called on events
+ * @param[in] arg Custom callback function context
+ *
+ */
+void gcoap_fileserver_set_event_cb(gcoap_fileserver_event_handler_t cb, void *arg);
+
 /**
  * @brief File server handler
  *

sys/net/application_layer/gcoap/fileserver.c

@@ -34,6 +34,21 @@
 /** Maximum length of an expressible path, including the trailing 0 character. */
 #define COAPFILESERVER_PATH_MAX (64)
 
+/**
+ * @brief fileserver event callback, only used with `gcoap_fileserver_callback`
+ */
+static gcoap_fileserver_event_handler_t _event_cb;
+
+/**
+ * @brief fileserver event callback context, only used with `gcoap_fileserver_callback`
+ */
+static void *_event_ctx;
+
+/**
+ * @brief fileserver event mutex, protects event cb and event ctx from concurrent access
+ */
+static mutex_t _event_mtx;
+
 /**
  * @brief Structure holding information about present options in a request
  */
@@ -146,6 +161,26 @@ static void _calc_szx2(coap_pkt_t *pdu, size_t reserve, coap_block1_t *block2)
  }
 }
 
+static inline void _event_file(gcoap_fileserver_event_t event, struct requestdata *request)
+{
+ if (!IS_USED(MODULE_GCOAP_FILESERVER_CALLBACK)) {
+ return;
+ }
+
+ mutex_lock(&_event_mtx);
+ gcoap_fileserver_event_ctx_t ctx = {
+ .path = request->namebuf,
+ .user_ctx = _event_ctx,
+ };
+
+ gcoap_fileserver_event_handler_t cb = _event_cb;
+ mutex_unlock(&_event_mtx);
+
+ if (cb) {
+ cb(event, &ctx);
+ }
+}
+
 static ssize_t _get_file(coap_pkt_t *pdu, uint8_t *buf, size_t len,
  struct requestdata *request)
 {
@@ -193,6 +228,10 @@ static ssize_t _get_file(coap_pkt_t *pdu, uint8_t *buf, size_t len,
  goto late_err;
  }
 
+ if (block2.blknum == 0) {
+ _event_file(GCOAP_FILESERVER_GET_FILE_START, request);
+ }
+
  /* That'd only happen if the buffer is too small for even a 16-byte block,
  * or if the above calculations were wrong.
  *
@@ -218,6 +257,10 @@ static ssize_t _get_file(coap_pkt_t *pdu, uint8_t *buf, size_t len,
  read -= 1;
  }
 
+ if (!more) {
+ _event_file(GCOAP_FILESERVER_GET_FILE_END, request);
+ }
+
  return resp_len + read;
 
 late_err:
@@ -257,6 +300,8 @@ static ssize_t _put_file(coap_pkt_t *pdu, uint8_t *buf, size_t len,
  ret = COAP_CODE_PRECONDITION_FAILED;
  goto unlink_on_error;
  }
+
+ _event_file(GCOAP_FILESERVER_PUT_FILE_START, request);
  }
  if (request->options.exists.if_match) {
  stat_etag(&stat, &etag); /* Etag before write */
@@ -310,6 +355,9 @@ static ssize_t _put_file(coap_pkt_t *pdu, uint8_t *buf, size_t len,
  goto unlink_on_error;
  }
  }
+
+ _event_file(GCOAP_FILESERVER_PUT_FILE_END, request);
+
  stat_etag(&stat, &etag); /* Etag after write */
  gcoap_resp_init(pdu, buf, len, create ? COAP_CODE_CREATED : COAP_CODE_CHANGED);
  coap_opt_add_opaque(pdu, COAP_OPT_ETAG, &etag, sizeof(etag));
@@ -347,6 +395,9 @@ static ssize_t _delete_file(coap_pkt_t *pdu, uint8_t *buf, size_t len,
  return gcoap_fileserver_error_handler(pdu, buf, len, COAP_CODE_PRECONDITION_FAILED);
  }
  }
+
+ _event_file(GCOAP_FILESERVER_DELETE_FILE, request);
+
  if ((ret = vfs_unlink(request->namebuf)) < 0) {
  return gcoap_fileserver_error_handler(pdu, buf, len, ret);
  }
@@ -644,4 +695,16 @@ ssize_t gcoap_fileserver_handler(coap_pkt_t *pdu, uint8_t *buf, size_t len,
  return gcoap_response(pdu, buf, len, errorcode);
 }
 
+#ifdef MODULE_GCOAP_FILESERVER_CALLBACK
+void gcoap_fileserver_set_event_cb(gcoap_fileserver_event_handler_t cb, void *ctx)
+{
+ mutex_lock(&_event_mtx);
+
+ _event_cb = cb;
+ _event_ctx = ctx;
+
+ mutex_unlock(&_event_mtx);
+}
+#endif
+
 /** @} */