1 files changed, 169 insertions, 0 deletions
diff --git a/examples/receiver.c b/examples/receiver.c
new file mode 100644
index 0000000..316e1ec
--- /dev/null
+++ b/examples/receiver.c
@@ -0,0 +1,169 @@
+#include <dnswire/reader.h>
+
+#include <stdio.h>
+#include <errno.h>
+#include <arpa/inet.h>
+#include <stdlib.h>
+#include <sys/socket.h>
+#include <netinet/in.h>
+#include <sys/un.h>
+
+#include "print_dnstap.c"
+
+int main(int argc, const char* argv[])
+{
+    if (argc < 2) {
+        fprintf(stderr, "usage: receiver [ <IP> <port> | <unix socket path> ]\n");
+        return 1;
+    }
+
+    /*
+     * We first initialize the reader and check that it can allocate the
+     * buffers it needs.
+     */
+
+    struct dnswire_reader reader;
+
+    if (dnswire_reader_init(&reader) != dnswire_ok) {
+        fprintf(stderr, "Unable to initialize dnswire reader\n");
+        return 1;
+    }
+
+    /*
+     * Allow bidirectional communication over the TCP or UNIX socket.
+     */
+    if (dnswire_reader_allow_bidirectional(&reader, true) != dnswire_ok) {
+        fprintf(stderr, "Unable to set dnswire reader to bidirectional mode\n");
+        return 1;
+    }
+
+    int sockfd;
+
+    if (argc == 2) {
+        /*
+         * We setup a unix socket at the given path on command line.
+         */
+
+        struct sockaddr_un path;
+
+        memset(&path, 0, sizeof(struct sockaddr_un));
+        path.sun_family = AF_UNIX;
+        strncpy(path.sun_path, argv[1], sizeof(path.sun_path) - 1);
+
+        sockfd = socket(AF_UNIX, SOCK_STREAM, 0);
+        if (sockfd == -1) {
+            fprintf(stderr, "socket() failed: %s\n", strerror(errno));
+            return 1;
+        }
+        printf("socket\n");
+
+        if (bind(sockfd, (struct sockaddr*)&path, sizeof(struct sockaddr_un))) {
+            fprintf(stderr, "bind() failed: %s\n", strerror(errno));
+            close(sockfd);
+            return 1;
+        }
+        printf("bind\n");
+    } else {
+        /*
+         * We setup and listen on the IP and port given on command line.
+         */
+
+        struct sockaddr_storage addr_store;
+        struct sockaddr_in*     addr = (struct sockaddr_in*)&addr_store;
+        socklen_t               addrlen;
+
+        if (strchr(argv[1], ':')) {
+            addr->sin_family = AF_INET6;
+            addrlen          = sizeof(struct sockaddr_in6);
+        } else {
+            addr->sin_family = AF_INET;
+            addrlen          = sizeof(struct sockaddr_in);
+        }
+
+        if (inet_pton(addr->sin_family, argv[1], &addr->sin_addr) != 1) {
+            fprintf(stderr, "inet_pton(%s) failed: %s\n", argv[1], strerror(errno));
+            return 1;
+        }
+
+        addr->sin_port = ntohs(atoi(argv[2]));
+
+        sockfd = socket(addr->sin_family, SOCK_STREAM, IPPROTO_TCP);
+        if (sockfd == -1) {
+            fprintf(stderr, "socket() failed: %s\n", strerror(errno));
+            return 1;
+        }
+        printf("socket\n");
+
+        if (bind(sockfd, (struct sockaddr*)addr, addrlen)) {
+            fprintf(stderr, "bind() failed: %s\n", strerror(errno));
+            close(sockfd);
+            return 1;
+        }
+        printf("bind\n");
+    }
+
+    if (listen(sockfd, 1)) {
+        fprintf(stderr, "listen() failed: %s\n", strerror(errno));
+        close(sockfd);
+        return 1;
+    }
+    printf("listen\n");
+
+    int clifd = accept(sockfd, 0, 0);
+    if (clifd < 0) {
+        fprintf(stderr, "accept() failed: %s\n", strerror(errno));
+        close(sockfd);
+        return 1;
+    }
+    printf("accept\n");
+
+    /*
+     * We have accepted connection from the sender!
+     *
+     * We now loop until we have a DNSTAP message, the stream was stopped
+     * or we got an error.
+     */
+
+    int done = 0;
+
+    printf("receiving...\n");
+    while (!done) {
+        switch (dnswire_reader_read(&reader, clifd)) {
+        case dnswire_have_dnstap:
+            /*
+             * We received a DNSTAP message, let's print it.
+             */
+            print_dnstap(dnswire_reader_dnstap(reader));
+            break;
+        case dnswire_again:
+        case dnswire_need_more:
+            /*
+             * This indicates that we need to call the reader again as it
+             * will only do one pass in a non-blocking fasion.
+             */
+            break;
+        case dnswire_endofdata:
+            /*
+             * The stream was stopped from the sender side, we're done!
+             */
+            printf("stopped\n");
+            done = 1;
+            break;
+        default:
+            fprintf(stderr, "dnswire_reader_read() error\n");
+            done = 1;
+        }
+    }
+
+    dnswire_reader_destroy(reader);
+
+    /*
+     * Time to exit, let's shutdown and close the sockets.
+     */
+
+    shutdown(clifd, SHUT_RDWR);
+    close(clifd);
+    close(sockfd);
+
+    return 0;
+}