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author | 2016-10-07 09:02:28 -0700 | |
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committer | 2016-10-07 09:02:28 -0700 | |
commit | 15195741d7758a80bcf901e7db05b3c57654c4a3 (patch) | |
tree | 1a7cd9f6b80235306559176a34bcf0e5c7ec4407 /third_party/nanopb/examples/network_server/server.c | |
parent | 2137cd8e9b84fd2f602a369ee5922a6fefce2efc (diff) | |
parent | e5c744d9850a763639b2e7001cf2487e1c76133b (diff) |
Merge remote-tracking branch 'upstream/master' into rename_client_config
Diffstat (limited to 'third_party/nanopb/examples/network_server/server.c')
-rw-r--r-- | third_party/nanopb/examples/network_server/server.c | 158 |
1 files changed, 158 insertions, 0 deletions
diff --git a/third_party/nanopb/examples/network_server/server.c b/third_party/nanopb/examples/network_server/server.c new file mode 100644 index 0000000000..46a5f38d1d --- /dev/null +++ b/third_party/nanopb/examples/network_server/server.c @@ -0,0 +1,158 @@ +/* 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; +} |