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author | 2017-05-02 17:51:53 +0200 | |
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committer | 2017-05-02 17:51:53 +0200 | |
commit | 3102ec9ce009d0f28355c5b7df9c5bd5013e6e75 (patch) | |
tree | 80a1ea19ff06cc9308b236a0d8d6358d21dd0381 /CAN-binder/libs/nanopb/examples/network_server/client.c | |
parent | 12e680a3c97a2750c657a8c561a79706f3689149 (diff) | |
parent | 278ffb890e3d8722e4c7d824baaf221a1e375fc4 (diff) |
Add 'CAN-binder/libs/nanopb/' from commit '278ffb890e3d8722e4c7d824baaf221a1e375fc4'
git-subtree-dir: CAN-binder/libs/nanopb
git-subtree-mainline: 12e680a3c97a2750c657a8c561a79706f3689149
git-subtree-split: 278ffb890e3d8722e4c7d824baaf221a1e375fc4
Diffstat (limited to 'CAN-binder/libs/nanopb/examples/network_server/client.c')
-rw-r--r-- | CAN-binder/libs/nanopb/examples/network_server/client.c | 142 |
1 files changed, 142 insertions, 0 deletions
diff --git a/CAN-binder/libs/nanopb/examples/network_server/client.c b/CAN-binder/libs/nanopb/examples/network_server/client.c new file mode 100644 index 00000000..00f6dab8 --- /dev/null +++ b/CAN-binder/libs/nanopb/examples/network_server/client.c @@ -0,0 +1,142 @@ +/* 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; +} |