150 lines
3.6 KiB
C
150 lines
3.6 KiB
C
/* 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.h"
|
|
|
|
bool write_callback(pb_ostream_t *stream, const uint8_t *buf, size_t count)
|
|
{
|
|
int fd = *(int*)stream->state;
|
|
return send(fd, buf, count, 0) == count;
|
|
}
|
|
|
|
bool read_callback(pb_istream_t *stream, uint8_t *buf, size_t count)
|
|
{
|
|
int fd = *(int*)stream->state;
|
|
|
|
if (buf == NULL)
|
|
{
|
|
/* Well, this is a really inefficient way to skip input. */
|
|
/* It is only used when there are unknown fields. */
|
|
char dummy;
|
|
while (count-- && recv(fd, &dummy, 1, 0) == 1);
|
|
return count == 0;
|
|
}
|
|
|
|
return recv(fd, buf, count, MSG_WAITALL) == count;
|
|
}
|
|
|
|
bool listdir_callback(pb_ostream_t *stream, const pb_field_t *field, const void *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';
|
|
|
|
if (!pb_encode_tag_for_field(stream, field))
|
|
return false;
|
|
|
|
if (!pb_enc_submessage(stream, field, &fileinfo))
|
|
return false;
|
|
}
|
|
|
|
return true;
|
|
}
|
|
|
|
void handle_connection(int connfd)
|
|
{
|
|
ListFilesRequest request;
|
|
ListFilesResponse response;
|
|
pb_istream_t input = {&read_callback, &connfd, SIZE_MAX};
|
|
pb_ostream_t output = {&write_callback, &connfd, SIZE_MAX, 0};
|
|
DIR *directory;
|
|
|
|
if (!pb_decode(&input, ListFilesRequest_fields, &request))
|
|
{
|
|
printf("Decoding failed.\n");
|
|
return;
|
|
}
|
|
|
|
directory = opendir(request.path);
|
|
|
|
printf("Listing directory: %s\n", request.path);
|
|
|
|
if (directory == NULL)
|
|
{
|
|
perror("opendir");
|
|
|
|
response.has_path_error = true;
|
|
response.path_error = true;
|
|
response.file.funcs.encode = NULL;
|
|
}
|
|
else
|
|
{
|
|
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.\n");
|
|
}
|
|
}
|
|
|
|
int main(int argc, char **argv)
|
|
{
|
|
int listenfd, connfd;
|
|
struct sockaddr_in servaddr;
|
|
|
|
listenfd = socket(AF_INET, SOCK_STREAM, 0);
|
|
|
|
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(;;)
|
|
{
|
|
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);
|
|
}
|
|
}
|