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-rw-r--r--third_party/nanopb/examples/network_server/client.c142
1 files changed, 142 insertions, 0 deletions
diff --git a/third_party/nanopb/examples/network_server/client.c b/third_party/nanopb/examples/network_server/client.c
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+/* This is a simple TCP client that connects to port 1234 and prints a list
+ * of files in a given directory.
+ *
+ * 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 for each filename received
+ * from the server. The filenames will be printed out immediately, so that
+ * no memory has to be allocated for them.
+ */
+bool printfile_callback(pb_istream_t *stream, const pb_field_t *field, void **arg)
+{
+ FileInfo fileinfo = {};
+
+ if (!pb_decode(stream, FileInfo_fields, &fileinfo))
+ return false;
+
+ printf("%-10lld %s\n", (long long)fileinfo.inode, fileinfo.name);
+
+ return true;
+}
+
+/* This function sends a request to socket 'fd' to list the files in
+ * directory given in 'path'. The results received from server will
+ * be printed to stdout.
+ */
+bool listdir(int fd, char *path)
+{
+ /* Construct and send the request to server */
+ {
+ ListFilesRequest request = {};
+ pb_ostream_t output = pb_ostream_from_socket(fd);
+ uint8_t zero = 0;
+
+ /* In our protocol, path is optional. If it is not given,
+ * the server will list the root directory. */
+ if (path == NULL)
+ {
+ request.has_path = false;
+ }
+ else
+ {
+ request.has_path = true;
+ if (strlen(path) + 1 > sizeof(request.path))
+ {
+ fprintf(stderr, "Too long path.\n");
+ return false;
+ }
+
+ strcpy(request.path, path);
+ }
+
+ /* Encode the request. It is written to the socket immediately
+ * through our custom stream. */
+ if (!pb_encode(&output, ListFilesRequest_fields, &request))
+ {
+ fprintf(stderr, "Encoding failed: %s\n", PB_GET_ERROR(&output));
+ return false;
+ }
+
+ /* We signal the end of request with a 0 tag. */
+ pb_write(&output, &zero, 1);
+ }
+
+ /* Read back the response from server */
+ {
+ ListFilesResponse response = {};
+ pb_istream_t input = pb_istream_from_socket(fd);
+
+ /* Give a pointer to our callback function, which will handle the
+ * filenames as they arrive. */
+ response.file.funcs.decode = &printfile_callback;
+
+ if (!pb_decode(&input, ListFilesResponse_fields, &response))
+ {
+ fprintf(stderr, "Decode failed: %s\n", PB_GET_ERROR(&input));
+ return false;
+ }
+
+ /* If the message from server decodes properly, but directory was
+ * not found on server side, we get path_error == true. */
+ if (response.path_error)
+ {
+ fprintf(stderr, "Server reported error.\n");
+ return false;
+ }
+ }
+
+ return true;
+}
+
+int main(int argc, char **argv)
+{
+ int sockfd;
+ struct sockaddr_in servaddr;
+ char *path = NULL;
+
+ if (argc > 1)
+ path = argv[1];
+
+ sockfd = socket(AF_INET, SOCK_STREAM, 0);
+
+ /* Connect to server running on localhost:1234 */
+ memset(&servaddr, 0, sizeof(servaddr));
+ servaddr.sin_family = AF_INET;
+ servaddr.sin_addr.s_addr = htonl(INADDR_LOOPBACK);
+ servaddr.sin_port = htons(1234);
+
+ if (connect(sockfd, (struct sockaddr *)&servaddr, sizeof(servaddr)) != 0)
+ {
+ perror("connect");
+ return 1;
+ }
+
+ /* Send the directory listing request */
+ if (!listdir(sockfd, path))
+ return 2;
+
+ /* Close connection */
+ close(sockfd);
+
+ return 0;
+}