1 /* This is a simple TCP client that connects to port 1234 and prints a list 2 * of files in a given directory. 3 * 4 * It directly deserializes and serializes messages from network, minimizing 5 * memory use. 6 * 7 * For flexibility, this example is implemented using posix api. 8 * In a real embedded system you would typically use some other kind of 9 * a communication and filesystem layer. 10 */ 11 12 #include <sys/socket.h> 13 #include <sys/types.h> 14 #include <netinet/in.h> 15 #include <unistd.h> 16 #include <dirent.h> 17 #include <stdio.h> 18 #include <string.h> 19 20 #include <pb_encode.h> 21 #include <pb_decode.h> 22 23 #include "fileproto.pb.h" 24 #include "common.h" 25 26 bool printfile_callback(pb_istream_t *stream, const pb_field_t *field, void **arg) 27 { 28 FileInfo fileinfo; 29 30 if (!pb_decode(stream, FileInfo_fields, &fileinfo)) 31 return false; 32 33 printf("%-10lld %s\n", (long long)fileinfo.inode, fileinfo.name); 34 35 return true; 36 } 37 38 bool listdir(int fd, char *path) 39 { 40 ListFilesRequest request; 41 ListFilesResponse response; 42 pb_istream_t input = pb_istream_from_socket(fd); 43 pb_ostream_t output = pb_ostream_from_socket(fd); 44 uint8_t zero = 0; 45 46 if (path == NULL) 47 { 48 request.has_path = false; 49 } 50 else 51 { 52 request.has_path = true; 53 if (strlen(path) + 1 > sizeof(request.path)) 54 { 55 fprintf(stderr, "Too long path.\n"); 56 return false; 57 } 58 59 strcpy(request.path, path); 60 } 61 62 if (!pb_encode(&output, ListFilesRequest_fields, &request)) 63 { 64 fprintf(stderr, "Encoding failed.\n"); 65 return false; 66 } 67 68 /* We signal the end of request with a 0 tag. */ 69 pb_write(&output, &zero, 1); 70 71 response.file.funcs.decode = &printfile_callback; 72 73 if (!pb_decode(&input, ListFilesResponse_fields, &response)) 74 { 75 fprintf(stderr, "Decode failed: %s\n", PB_GET_ERROR(&input)); 76 return false; 77 } 78 79 if (response.path_error) 80 { 81 fprintf(stderr, "Server reported error.\n"); 82 return false; 83 } 84 85 return true; 86 } 87 88 int main(int argc, char **argv) 89 { 90 int sockfd; 91 struct sockaddr_in servaddr; 92 char *path = NULL; 93 94 if (argc > 1) 95 path = argv[1]; 96 97 sockfd = socket(AF_INET, SOCK_STREAM, 0); 98 99 memset(&servaddr, 0, sizeof(servaddr)); 100 servaddr.sin_family = AF_INET; 101 servaddr.sin_addr.s_addr = htonl(INADDR_LOOPBACK); 102 servaddr.sin_port = htons(1234); 103 104 if (connect(sockfd, (struct sockaddr *)&servaddr, sizeof(servaddr)) != 0) 105 { 106 perror("connect"); 107 return 1; 108 } 109 110 if (!listdir(sockfd, path)) 111 return 2; 112 113 close(sockfd); 114 115 return 0; 116 } 117