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-rw-r--r--libs/nanopb/examples/network_server/server.c158
1 files changed, 158 insertions, 0 deletions
diff --git a/libs/nanopb/examples/network_server/server.c b/libs/nanopb/examples/network_server/server.c
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+++ b/libs/nanopb/examples/network_server/server.c
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+/* This is a simple TCP server that listens on port 1234 and provides lists
+ * of files to clients, using a protocol defined in file_server.proto.
+ *
+ * It directly deserializes and serializes messages from network, minimizing
+ * memory use.
+ *
+ * For flexibility, this example is implemented using posix api.
+ * In a real embedded system you would typically use some other kind of
+ * a communication and filesystem layer.
+ */
+
+#include <sys/socket.h>
+#include <sys/types.h>
+#include <netinet/in.h>
+#include <unistd.h>
+#include <dirent.h>
+#include <stdio.h>
+#include <string.h>
+
+#include <pb_encode.h>
+#include <pb_decode.h>
+
+#include "fileproto.pb.h"
+#include "common.h"
+
+/* This callback function will be called once during the encoding.
+ * It will write out any number of FileInfo entries, without consuming unnecessary memory.
+ * This is accomplished by fetching the filenames one at a time and encoding them
+ * immediately.
+ */
+bool listdir_callback(pb_ostream_t *stream, const pb_field_t *field, void * const *arg)
+{
+ DIR *dir = (DIR*) *arg;
+ struct dirent *file;
+ FileInfo fileinfo = {};
+
+ while ((file = readdir(dir)) != NULL)
+ {
+ fileinfo.inode = file->d_ino;
+ strncpy(fileinfo.name, file->d_name, sizeof(fileinfo.name));
+ fileinfo.name[sizeof(fileinfo.name) - 1] = '\0';
+
+ /* This encodes the header for the field, based on the constant info
+ * from pb_field_t. */
+ if (!pb_encode_tag_for_field(stream, field))
+ return false;
+
+ /* This encodes the data for the field, based on our FileInfo structure. */
+ if (!pb_encode_submessage(stream, FileInfo_fields, &fileinfo))
+ return false;
+ }
+
+ return true;
+}
+
+/* Handle one arriving client connection.
+ * Clients are expected to send a ListFilesRequest, terminated by a '0'.
+ * Server will respond with a ListFilesResponse message.
+ */
+void handle_connection(int connfd)
+{
+ DIR *directory = NULL;
+
+ /* Decode the message from the client and open the requested directory. */
+ {
+ ListFilesRequest request = {};
+ pb_istream_t input = pb_istream_from_socket(connfd);
+
+ if (!pb_decode(&input, ListFilesRequest_fields, &request))
+ {
+ printf("Decode failed: %s\n", PB_GET_ERROR(&input));
+ return;
+ }
+
+ directory = opendir(request.path);
+ printf("Listing directory: %s\n", request.path);
+ }
+
+ /* List the files in the directory and transmit the response to client */
+ {
+ ListFilesResponse response = {};
+ pb_ostream_t output = pb_ostream_from_socket(connfd);
+
+ if (directory == NULL)
+ {
+ perror("opendir");
+
+ /* Directory was not found, transmit error status */
+ response.has_path_error = true;
+ response.path_error = true;
+ response.file.funcs.encode = NULL;
+ }
+ else
+ {
+ /* Directory was found, transmit filenames */
+ response.has_path_error = false;
+ response.file.funcs.encode = &listdir_callback;
+ response.file.arg = directory;
+ }
+
+ if (!pb_encode(&output, ListFilesResponse_fields, &response))
+ {
+ printf("Encoding failed: %s\n", PB_GET_ERROR(&output));
+ }
+ }
+
+ if (directory != NULL)
+ closedir(directory);
+}
+
+int main(int argc, char **argv)
+{
+ int listenfd, connfd;
+ struct sockaddr_in servaddr;
+ int reuse = 1;
+
+ /* Listen on localhost:1234 for TCP connections */
+ listenfd = socket(AF_INET, SOCK_STREAM, 0);
+ setsockopt(listenfd, SOL_SOCKET, SO_REUSEADDR, &reuse, sizeof(reuse));
+
+ memset(&servaddr, 0, sizeof(servaddr));
+ servaddr.sin_family = AF_INET;
+ servaddr.sin_addr.s_addr = htonl(INADDR_LOOPBACK);
+ servaddr.sin_port = htons(1234);
+ if (bind(listenfd, (struct sockaddr*)&servaddr, sizeof(servaddr)) != 0)
+ {
+ perror("bind");
+ return 1;
+ }
+
+ if (listen(listenfd, 5) != 0)
+ {
+ perror("listen");
+ return 1;
+ }
+
+ for(;;)
+ {
+ /* Wait for a client */
+ connfd = accept(listenfd, NULL, NULL);
+
+ if (connfd < 0)
+ {
+ perror("accept");
+ return 1;
+ }
+
+ printf("Got connection.\n");
+
+ handle_connection(connfd);
+
+ printf("Closing connection.\n");
+
+ close(connfd);
+ }
+
+ return 0;
+}