1 /* This is a simple TCP server that listens on port 1234 and provides lists
2 * of files to clients, using a protocol defined in file_server.proto.
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
listdir_callback(pb_ostream_t * stream,const pb_field_t * field,void * const * arg)26 bool listdir_callback(pb_ostream_t *stream, const pb_field_t *field, void * const *arg)
27 {
28 DIR *dir = (DIR*) *arg;
29 struct dirent *file;
30 FileInfo fileinfo;
31
32 while ((file = readdir(dir)) != NULL)
33 {
34 fileinfo.inode = file->d_ino;
35 strncpy(fileinfo.name, file->d_name, sizeof(fileinfo.name));
36 fileinfo.name[sizeof(fileinfo.name) - 1] = '\0';
37
38 if (!pb_encode_tag_for_field(stream, field))
39 return false;
40
41 if (!pb_encode_submessage(stream, FileInfo_fields, &fileinfo))
42 return false;
43 }
44
45 return true;
46 }
47
handle_connection(int connfd)48 void handle_connection(int connfd)
49 {
50 ListFilesRequest request;
51 ListFilesResponse response;
52 pb_istream_t input = pb_istream_from_socket(connfd);
53 pb_ostream_t output = pb_ostream_from_socket(connfd);
54 DIR *directory;
55
56 if (!pb_decode(&input, ListFilesRequest_fields, &request))
57 {
58 printf("Decode failed: %s\n", PB_GET_ERROR(&input));
59 return;
60 }
61
62 directory = opendir(request.path);
63
64 printf("Listing directory: %s\n", request.path);
65
66 if (directory == NULL)
67 {
68 perror("opendir");
69
70 response.has_path_error = true;
71 response.path_error = true;
72 response.file.funcs.encode = NULL;
73 }
74 else
75 {
76 response.has_path_error = false;
77 response.file.funcs.encode = &listdir_callback;
78 response.file.arg = directory;
79 }
80
81 if (!pb_encode(&output, ListFilesResponse_fields, &response))
82 {
83 printf("Encoding failed.\n");
84 }
85 }
86
main(int argc,char ** argv)87 int main(int argc, char **argv)
88 {
89 int listenfd, connfd;
90 struct sockaddr_in servaddr;
91 int reuse = 1;
92
93 listenfd = socket(AF_INET, SOCK_STREAM, 0);
94
95 setsockopt(listenfd, SOL_SOCKET, SO_REUSEADDR, &reuse, sizeof(reuse));
96
97 memset(&servaddr, 0, sizeof(servaddr));
98 servaddr.sin_family = AF_INET;
99 servaddr.sin_addr.s_addr = htonl(INADDR_LOOPBACK);
100 servaddr.sin_port = htons(1234);
101 if (bind(listenfd, (struct sockaddr*)&servaddr, sizeof(servaddr)) != 0)
102 {
103 perror("bind");
104 return 1;
105 }
106
107 if (listen(listenfd, 5) != 0)
108 {
109 perror("listen");
110 return 1;
111 }
112
113 for(;;)
114 {
115 connfd = accept(listenfd, NULL, NULL);
116
117 if (connfd < 0)
118 {
119 perror("accept");
120 return 1;
121 }
122
123 printf("Got connection.\n");
124
125 handle_connection(connfd);
126
127 printf("Closing connection.\n");
128
129 close(connfd);
130 }
131 }
132