Separation Generator to a dedicated repo

Change-Id: Id94831651c3266861435272a6e36c7884bef2c45
Signed-off-by: Romain Forlot <romain.forlot@iot.bzh>

1 files changed, 142 insertions, 0 deletions

diff --git a/libs/nanopb/examples/network_server/client.c b/libs/nanopb/examples/network_server/client.c
new file mode 100644
index 00000000..00f6dab8
--- /dev/null
+++ b/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;
+}