devices/vsock: integration test

Added a vsock integration test, along with a new testing tool
(tests/host_tools/vsock_helper.c).

Signed-off-by: Dan Horobeanu <[email protected]>

Author: dhrgit

tests/conftest.py

@@ -230,6 +230,15 @@ def aux_bin_paths(test_session_root_path):
         cloner_bin_path
     )
 
+    vsock_helper_bin_path = os.path.join(
+        test_session_root_path,
+        'vsock_helper'
+    )
+    _gcc_compile(
+        'host_tools/vsock_helper.c',
+        vsock_helper_bin_path
+    )
+
     seccomp_build_path = os.path.join(
         test_session_root_path,
         build_tools.CARGO_RELEASE_REL_PATH
@@ -274,6 +283,7 @@ def aux_bin_paths(test_session_root_path):
 
     yield {
         'cloner': cloner_bin_path,
+        'vsock_helper': vsock_helper_bin_path,
         'demo_basic_jailer': demo_basic_jailer,
         'demo_advanced_jailer': demo_advanced_jailer,
         'demo_harmless': demo_harmless,

tests/host_tools/vsock_helper.c

@@ -0,0 +1,206 @@
+// Copyright 2018 Amazon.com, Inc. or its affiliates. All Rights Reserved.
+// SPDX-License-Identifier: Apache-2.0
+
+// This is a vsock helper tool, used by the Firecracker integration tests,
+// to - well - test the virtio vsock device. It can be used to:
+// 1. Run a forking echo server, that echoes back any data received from
+//    a client; and
+// 2. Run a vsock echo client, that reads data from STDIN, sends it to an
+//    echo server, then forwards the server's reply to STDOUT.
+
+#include <sys/socket.h>
+#include <sys/types.h>
+#include <sys/select.h>
+#include <sys/wait.h>
+#include <linux/vm_sockets.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <stdint.h>
+#include <string.h>
+#include <unistd.h>
+#include <stdio.h>
+#include <errno.h>
+
+
+#define BUF_SIZE (16 * 1024)
+#define SERVER_ACCEPT_BACKLOG 128
+
+
+int print_usage() {
+    fprintf(stderr, "Usage: ./vsock-helper {echosrv [-d] <port> | echo <cid> <port>}\n");
+    fprintf(stderr, "\n");
+    fprintf(stderr, "  echosrv       start a vsock echo server. The server will accept\n");
+    fprintf(stderr, "                any incoming connection, and echo back any data\n");
+    fprintf(stderr, "                received on it.\n");
+    fprintf(stderr, "                -d can be used to daemonize the server.\n");
+    fprintf(stderr, "\n");
+    fprintf(stderr, "  echo          connect to an echo server, listening on CID:port.\n");
+    fprintf(stderr, "                STDIN will be piped through to the echo server, and\n");
+    fprintf(stderr, "                data coming from the server will pe sent to STDOUT.\n");
+    fprintf(stderr, "\n");
+    return -1;
+}
+
+int xfer(int src_fd, int dst_fd) {
+    char buf[BUF_SIZE];
+    int count =  read(src_fd, buf, sizeof(buf));
+
+    if (!count) return 0;
+    if (count < 0) return -1;
+
+    int offset = 0;
+    do {
+        int written;
+        written = write(dst_fd, &buf[offset], count - offset);
+        if (written <= 0) return -1;
+        offset += written;
+    } while (offset < count);
+
+    return offset;
+}
+
+
+int run_echosrv(uint32_t port) {
+
+    struct sockaddr_vm vsock_addr = {
+        .svm_family = AF_VSOCK,
+        .svm_port = port,
+        .svm_cid = VMADDR_CID_ANY
+    };
+
+    int srv_sock = socket(AF_VSOCK, SOCK_STREAM, 0);
+    if (srv_sock < 0) {
+        perror("socket()");
+        return -1;
+    }
+
+    int res = bind(srv_sock, (struct sockaddr*)&vsock_addr, sizeof(struct sockaddr_vm));
+    if (res) {
+        perror("bind()");
+        return -1;
+    }
+
+    res = listen(srv_sock, SERVER_ACCEPT_BACKLOG);
+    if (res) {
+        perror("listen()");
+        return -1;
+    }
+
+    for (;;) {
+        struct sockaddr cl_addr;
+        socklen_t sockaddr_len = sizeof(cl_addr);
+        int cl_sock = accept(srv_sock, &cl_addr, &sockaddr_len);
+        if (cl_sock < 0) {
+            perror("accept()");
+            continue;
+        }
+
+        int pid = fork();
+        if (pid < 0) {
+            perror("fork()");
+            close(cl_sock);
+            continue;
+        }
+
+        if (!pid) {
+            int res;
+            do {
+                res = xfer(cl_sock, cl_sock);
+            } while (res > 0);
+            return res >= 0 ? 0 : -1;
+        }
+
+        close(cl_sock);
+        int cstatus;
+        waitpid(-1, &cstatus, WNOHANG);
+        printf("New client forked...\n");
+    }
+
+	return 0;
+}
+
+
+int run_echo(uint32_t cid, uint32_t port) {
+
+    int sock = socket(AF_VSOCK, SOCK_STREAM, 0);
+    if (sock < 0) {
+        perror("socket()");
+        return -1;
+    }
+
+    struct sockaddr_vm vsock_addr = {
+        .svm_family = AF_VSOCK,
+        .svm_port = port,
+        .svm_cid = cid
+    };
+    if (connect(sock, (struct sockaddr*)&vsock_addr, sizeof(vsock_addr)) < 0) {
+        perror("connect()");
+        return -1;
+    }
+
+    for (;;) {
+        int ping_cnt = xfer(STDIN_FILENO, sock);
+        if (!ping_cnt) break;
+        if (ping_cnt < 0) return -1;
+
+        int pong_cnt = 0;
+        while (pong_cnt < ping_cnt) {
+            int res = xfer(sock, STDOUT_FILENO);
+            if (res <= 0) return -1;
+            pong_cnt += res;
+        }
+    }
+
+    return 0;
+}
+
+
+int main(int argc, char **argv) {
+
+    if (argc < 3) {
+        return print_usage();
+    }
+
+    if (strcmp(argv[1], "echosrv") == 0) {
+        uint32_t port;
+        if (strcmp(argv[2], "-d") == 0) {
+            if (argc < 4) {
+                return print_usage();
+            }
+            port = atoi(argv[3]);
+            if (!port) {
+                return print_usage();
+            }
+            int pid = fork();
+            if (pid < 0) return -1;
+            if (pid) {
+                printf("Forked vsock echo daemon listening on port %d\n", port);
+                return 0;
+            }
+            setsid();
+            close(STDIN_FILENO);
+            close(STDOUT_FILENO);
+        }
+        else {
+            port = atoi(argv[2]);
+            if (!port) {
+                return print_usage();
+            }
+        }
+        return run_echosrv(port);
+    }
+
+    if (strcmp(argv[1], "echo") == 0) {
+        if (argc != 4) {
+            return print_usage();
+        }
+        uint32_t cid = atoi(argv[2]);
+        uint32_t port = atoi(argv[3]);
+        if (!cid || !port) {
+            return print_usage();
+        }
+        return run_echo(cid, port);
+    }
+
+    return print_usage();
+}