Vitaliy Filippov
4a2dcf7b6b
VNPL 1.1 is slightly reworded to make it clear that proprietary software interacting with Vitastor and providing some kind of service to end users isn't a "Proxy Program" if it's not specially designed to be used with Vitastor. For example, Windows OS running in a virtual machine stored in a Vitastor cluster clearly isn't.
678 lines
19 KiB
C++
678 lines
19 KiB
C++
// Copyright (c) Vitaliy Filippov, 2019+
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// License: VNPL-1.1 (see README.md for details)
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// Similar to qemu-nbd, but sets timeout and uses io_uring
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#include <linux/nbd.h>
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#include <sys/ioctl.h>
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#include <sys/socket.h>
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#include <netinet/in.h>
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#include <netinet/tcp.h>
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#include <arpa/inet.h>
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#include <sys/un.h>
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#include <unistd.h>
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#include <fcntl.h>
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#include <signal.h>
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#include "epoll_manager.h"
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#include "cluster_client.h"
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#ifndef MSG_ZEROCOPY
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#define MSG_ZEROCOPY 0
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#endif
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const char *exe_name = NULL;
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class nbd_proxy
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{
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protected:
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uint64_t inode = 0;
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ring_loop_t *ringloop = NULL;
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epoll_manager_t *epmgr = NULL;
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cluster_client_t *cli = NULL;
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ring_consumer_t consumer;
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std::vector<iovec> send_list, next_send_list;
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std::vector<void*> to_free;
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int nbd_fd = -1;
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void *recv_buf = NULL;
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int receive_buffer_size = 9000;
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nbd_request cur_req;
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cluster_op_t *cur_op = NULL;
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void *cur_buf = NULL;
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int cur_left = 0;
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int read_state = 0;
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int read_ready = 0;
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msghdr read_msg = { 0 }, send_msg = { 0 };
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iovec read_iov = { 0 };
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public:
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static json11::Json::object parse_args(int narg, const char *args[])
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{
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json11::Json::object cfg;
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int pos = 0;
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for (int i = 1; i < narg; i++)
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{
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if (!strcmp(args[i], "-h") || !strcmp(args[i], "--help"))
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{
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help();
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}
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else if (args[i][0] == '-' && args[i][1] == '-')
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{
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const char *opt = args[i]+2;
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cfg[opt] = !strcmp(opt, "json") || i == narg-1 ? "1" : args[++i];
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}
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else if (pos == 0)
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{
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cfg["command"] = args[i];
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pos++;
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}
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else if (pos == 1 && (cfg["command"] == "map" || cfg["command"] == "unmap"))
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{
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int n = 0;
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if (sscanf(args[i], "/dev/nbd%d", &n) > 0)
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cfg["dev_num"] = n;
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else
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cfg["dev_num"] = args[i];
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pos++;
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}
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}
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return cfg;
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}
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void exec(json11::Json cfg)
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{
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if (cfg["command"] == "map")
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{
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start(cfg);
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}
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else if (cfg["command"] == "unmap")
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{
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if (cfg["dev_num"].is_null())
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{
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fprintf(stderr, "device name or number is missing\n");
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exit(1);
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}
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unmap(cfg["dev_num"].uint64_value());
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}
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else if (cfg["command"] == "list" || cfg["command"] == "list-mapped")
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{
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auto mapped = list_mapped();
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print_mapped(mapped, !cfg["json"].is_null());
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}
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else
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{
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help();
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}
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}
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static void help()
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{
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printf(
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"Vitastor NBD proxy\n"
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"(c) Vitaliy Filippov, 2020 (VNPL-1.1)\n\n"
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"USAGE:\n"
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" %s map --etcd_address <etcd_address> --pool <pool> --inode <inode> --size <size in bytes>\n"
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" %s unmap /dev/nbd0\n"
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" %s list [--json]\n",
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exe_name, exe_name, exe_name
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);
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exit(0);
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}
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void unmap(int dev_num)
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{
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char path[64] = { 0 };
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sprintf(path, "/dev/nbd%d", dev_num);
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int r, nbd = open(path, O_RDWR);
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if (nbd < 0)
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{
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perror("open");
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exit(1);
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}
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r = ioctl(nbd, NBD_DISCONNECT);
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if (r < 0)
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{
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perror("NBD_DISCONNECT");
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exit(1);
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}
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close(nbd);
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}
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void start(json11::Json cfg)
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{
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// Check options
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if (cfg["etcd_address"].string_value() == "")
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{
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fprintf(stderr, "etcd_address is missing\n");
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exit(1);
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}
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if (!cfg["size"].uint64_value())
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{
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fprintf(stderr, "device size is missing\n");
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exit(1);
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}
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inode = cfg["inode"].uint64_value();
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uint64_t pool = cfg["pool"].uint64_value();
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if (pool)
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{
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inode = (inode & ((1l << (64-POOL_ID_BITS)) - 1)) | (pool << (64-POOL_ID_BITS));
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}
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if (!(inode >> (64-POOL_ID_BITS)))
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{
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fprintf(stderr, "pool is missing\n");
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exit(1);
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}
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// Initialize NBD
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int sockfd[2];
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if (socketpair(AF_UNIX, SOCK_STREAM, 0, sockfd) < 0)
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{
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perror("socketpair");
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exit(1);
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}
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fcntl(sockfd[0], F_SETFL, fcntl(sockfd[0], F_GETFL, 0) | O_NONBLOCK);
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nbd_fd = sockfd[0];
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load_module();
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if (!cfg["dev_num"].is_null())
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{
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if (run_nbd(sockfd, cfg["dev_num"].int64_value(), cfg["size"].uint64_value(), NBD_FLAG_SEND_FLUSH, 30) < 0)
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{
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perror("run_nbd");
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exit(1);
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}
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}
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else
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{
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// Find an unused device
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int i = 0;
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while (true)
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{
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int r = run_nbd(sockfd, i, cfg["size"].uint64_value(), NBD_FLAG_SEND_FLUSH, 30);
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if (r == 0)
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{
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printf("/dev/nbd%d\n", i);
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break;
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}
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else if (r == -1 && errno == ENOENT)
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{
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fprintf(stderr, "No free NBD devices found\n");
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exit(1);
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}
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else if (r == -2 && errno == EBUSY)
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{
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i++;
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}
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else
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{
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printf("%d %d\n", r, errno);
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perror("run_nbd");
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exit(1);
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}
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}
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}
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if (cfg["foreground"].is_null())
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{
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daemonize();
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}
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// Create client
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ringloop = new ring_loop_t(512);
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epmgr = new epoll_manager_t(ringloop);
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cli = new cluster_client_t(ringloop, epmgr->tfd, cfg);
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// Initialize read state
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read_state = CL_READ_HDR;
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recv_buf = malloc_or_die(receive_buffer_size);
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cur_buf = &cur_req;
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cur_left = sizeof(nbd_request);
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consumer.loop = [this]()
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{
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submit_read();
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submit_send();
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ringloop->submit();
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};
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ringloop->register_consumer(&consumer);
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// Add FD to epoll
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epmgr->tfd->set_fd_handler(sockfd[0], false, [this](int peer_fd, int epoll_events)
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{
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read_ready++;
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submit_read();
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});
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while (1)
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{
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ringloop->loop();
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ringloop->wait();
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}
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}
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void load_module()
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{
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if (access("/sys/module/nbd", F_OK))
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{
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return;
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}
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int r;
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if ((r = system("modprobe nbd")) != 0)
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{
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if (r < 0)
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perror("Failed to load NBD kernel module");
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else
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fprintf(stderr, "Failed to load NBD kernel module\n");
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exit(1);
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}
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}
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void daemonize()
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{
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if (fork())
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exit(0);
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setsid();
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if (fork())
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exit(0);
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chdir("/");
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close(0);
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close(1);
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close(2);
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open("/dev/null", O_RDONLY);
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open("/dev/null", O_WRONLY);
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open("/dev/null", O_WRONLY);
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}
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json11::Json::object list_mapped()
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{
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const char *self_filename = exe_name;
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for (int i = 0; exe_name[i] != 0; i++)
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{
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if (exe_name[i] == '/')
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self_filename = exe_name+i+1;
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}
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char path[64] = { 0 };
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json11::Json::object mapped;
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int dev_num = -1;
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int pid;
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while (true)
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{
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dev_num++;
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sprintf(path, "/sys/block/nbd%d", dev_num);
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if (access(path, F_OK) != 0)
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break;
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sprintf(path, "/sys/block/nbd%d/pid", dev_num);
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std::string pid_str = read_file(path);
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if (pid_str == "")
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continue;
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if (sscanf(pid_str.c_str(), "%d", &pid) < 1)
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{
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printf("Failed to read pid from /sys/block/nbd%d/pid\n", dev_num);
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continue;
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}
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sprintf(path, "/proc/%d/cmdline", pid);
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std::string cmdline = read_file(path);
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std::vector<const char*> argv;
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int last = 0;
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for (int i = 0; i < cmdline.size(); i++)
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{
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if (cmdline[i] == 0)
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{
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argv.push_back(cmdline.c_str()+last);
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last = i+1;
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}
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}
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if (argv.size() > 0)
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{
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const char *pid_filename = argv[0];
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for (int i = 0; argv[0][i] != 0; i++)
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{
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if (argv[0][i] == '/')
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pid_filename = argv[0]+i+1;
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}
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if (!strcmp(pid_filename, self_filename))
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{
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json11::Json::object cfg = nbd_proxy::parse_args(argv.size(), argv.data());
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if (cfg["command"] == "map")
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{
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cfg.erase("command");
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cfg["pid"] = pid;
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mapped["/dev/nbd"+std::to_string(dev_num)] = cfg;
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}
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}
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}
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}
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return mapped;
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}
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void print_mapped(json11::Json mapped, bool json)
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{
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if (json)
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{
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printf("%s\n", mapped.dump().c_str());
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}
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else
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{
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for (auto & dev: mapped.object_items())
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{
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printf("%s\n", dev.first.c_str());
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for (auto & k: dev.second.object_items())
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{
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printf("%s: %s\n", k.first.c_str(), k.second.string_value().c_str());
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}
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printf("\n");
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}
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}
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}
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std::string read_file(char *path)
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{
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int fd = open(path, O_RDONLY);
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if (fd < 0)
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{
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if (errno == ENOENT)
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return "";
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auto err = "open "+std::string(path);
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perror(err.c_str());
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exit(1);
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}
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std::string r;
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while (true)
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{
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int l = r.size();
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r.resize(l + 1024);
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int rd = read(fd, (void*)(r.c_str() + l), 1024);
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if (rd <= 0)
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{
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r.resize(l);
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break;
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}
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r.resize(l + rd);
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}
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close(fd);
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return r;
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}
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protected:
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int run_nbd(int sockfd[2], int dev_num, uint64_t size, uint64_t flags, unsigned timeout)
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{
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// Check handle size
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assert(sizeof(cur_req.handle) == 8);
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char path[64] = { 0 };
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sprintf(path, "/dev/nbd%d", dev_num);
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int r, nbd = open(path, O_RDWR), qd_fd;
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if (nbd < 0)
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{
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return -1;
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}
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r = ioctl(nbd, NBD_SET_SOCK, sockfd[1]);
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if (r < 0)
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{
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goto end_close;
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}
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r = ioctl(nbd, NBD_SET_BLKSIZE, 4096);
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if (r < 0)
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{
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goto end_unmap;
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}
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r = ioctl(nbd, NBD_SET_SIZE, size);
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if (r < 0)
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{
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goto end_unmap;
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}
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ioctl(nbd, NBD_SET_FLAGS, flags);
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if (timeout >= 0)
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{
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r = ioctl(nbd, NBD_SET_TIMEOUT, (unsigned long)timeout);
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if (r < 0)
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{
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goto end_unmap;
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}
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}
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// Configure request size
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sprintf(path, "/sys/block/nbd%d/queue/max_sectors_kb", dev_num);
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qd_fd = open(path, O_WRONLY);
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if (qd_fd < 0)
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{
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goto end_unmap;
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}
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write(qd_fd, "32768", 5);
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close(qd_fd);
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if (!fork())
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{
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// Run in child
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close(sockfd[0]);
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r = ioctl(nbd, NBD_DO_IT);
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if (r < 0)
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{
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fprintf(stderr, "NBD device terminated with error: %s\n", strerror(errno));
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kill(getppid(), SIGTERM);
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}
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close(sockfd[1]);
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ioctl(nbd, NBD_CLEAR_QUE);
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ioctl(nbd, NBD_CLEAR_SOCK);
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exit(0);
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}
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close(sockfd[1]);
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close(nbd);
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return 0;
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end_close:
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r = errno;
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close(nbd);
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errno = r;
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return -2;
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end_unmap:
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r = errno;
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ioctl(nbd, NBD_CLEAR_SOCK);
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close(nbd);
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errno = r;
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return -3;
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}
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void submit_send()
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{
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if (!send_list.size() || send_msg.msg_iovlen > 0)
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{
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return;
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}
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io_uring_sqe* sqe = ringloop->get_sqe();
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if (!sqe)
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{
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return;
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}
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ring_data_t* data = ((ring_data_t*)sqe->user_data);
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data->callback = [this](ring_data_t *data) { handle_send(data->res); };
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send_msg.msg_iov = send_list.data();
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send_msg.msg_iovlen = send_list.size();
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my_uring_prep_sendmsg(sqe, nbd_fd, &send_msg, MSG_ZEROCOPY);
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}
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void handle_send(int result)
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{
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send_msg.msg_iovlen = 0;
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if (result < 0 && result != -EAGAIN)
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{
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fprintf(stderr, "Socket disconnected: %s\n", strerror(-result));
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exit(1);
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}
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int to_eat = 0;
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while (result > 0 && to_eat < send_list.size())
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{
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if (result >= send_list[to_eat].iov_len)
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{
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free(to_free[to_eat]);
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result -= send_list[to_eat].iov_len;
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to_eat++;
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}
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else
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{
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send_list[to_eat].iov_base += result;
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send_list[to_eat].iov_len -= result;
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break;
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}
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}
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if (to_eat > 0)
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{
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send_list.erase(send_list.begin(), send_list.begin() + to_eat);
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to_free.erase(to_free.begin(), to_free.begin() + to_eat);
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}
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for (int i = 0; i < next_send_list.size(); i++)
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{
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send_list.push_back(next_send_list[i]);
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}
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next_send_list.clear();
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if (send_list.size() > 0)
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{
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ringloop->wakeup();
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}
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}
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void submit_read()
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{
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if (!read_ready || read_msg.msg_iovlen > 0)
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{
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return;
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}
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io_uring_sqe* sqe = ringloop->get_sqe();
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if (!sqe)
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{
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return;
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}
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ring_data_t* data = ((ring_data_t*)sqe->user_data);
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data->callback = [this](ring_data_t *data) { handle_read(data->res); };
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if (cur_left < receive_buffer_size)
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{
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read_iov.iov_base = recv_buf;
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read_iov.iov_len = receive_buffer_size;
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}
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else
|
|
{
|
|
read_iov.iov_base = cur_buf;
|
|
read_iov.iov_len = cur_left;
|
|
}
|
|
read_msg.msg_iov = &read_iov;
|
|
read_msg.msg_iovlen = 1;
|
|
my_uring_prep_recvmsg(sqe, nbd_fd, &read_msg, 0);
|
|
}
|
|
|
|
void handle_read(int result)
|
|
{
|
|
read_msg.msg_iovlen = 0;
|
|
if (result < 0 && result != -EAGAIN)
|
|
{
|
|
fprintf(stderr, "Socket disconnected: %s\n", strerror(-result));
|
|
exit(1);
|
|
}
|
|
if (result == -EAGAIN || result < read_iov.iov_len)
|
|
{
|
|
read_ready--;
|
|
}
|
|
if (read_ready > 0)
|
|
{
|
|
ringloop->wakeup();
|
|
}
|
|
void *b = recv_buf;
|
|
while (result > 0)
|
|
{
|
|
if (read_iov.iov_base == recv_buf)
|
|
{
|
|
int inc = result >= cur_left ? cur_left : result;
|
|
memcpy(cur_buf, b, inc);
|
|
cur_left -= inc;
|
|
result -= inc;
|
|
cur_buf += inc;
|
|
b += inc;
|
|
}
|
|
else
|
|
{
|
|
assert(result <= cur_left);
|
|
cur_left -= result;
|
|
result = 0;
|
|
}
|
|
if (cur_left <= 0)
|
|
{
|
|
handle_finished_read();
|
|
}
|
|
}
|
|
}
|
|
|
|
void handle_finished_read()
|
|
{
|
|
if (read_state == CL_READ_HDR)
|
|
{
|
|
int req_type = be32toh(cur_req.type);
|
|
if (be32toh(cur_req.magic) != NBD_REQUEST_MAGIC ||
|
|
req_type != NBD_CMD_READ && req_type != NBD_CMD_WRITE && req_type != NBD_CMD_FLUSH)
|
|
{
|
|
printf("Unexpected request: magic=%x type=%x, terminating\n", cur_req.magic, req_type);
|
|
exit(1);
|
|
}
|
|
uint64_t handle = *((uint64_t*)cur_req.handle);
|
|
#ifdef DEBUG
|
|
printf("request %lx +%x %lx\n", be64toh(cur_req.from), be32toh(cur_req.len), handle);
|
|
#endif
|
|
void *buf = NULL;
|
|
cluster_op_t *op = new cluster_op_t;
|
|
if (req_type == NBD_CMD_READ || req_type == NBD_CMD_WRITE)
|
|
{
|
|
op->opcode = req_type == NBD_CMD_READ ? OSD_OP_READ : OSD_OP_WRITE;
|
|
op->inode = inode;
|
|
op->offset = be64toh(cur_req.from);
|
|
op->len = be32toh(cur_req.len);
|
|
buf = malloc_or_die(sizeof(nbd_reply) + op->len);
|
|
op->iov.push_back(buf + sizeof(nbd_reply), op->len);
|
|
}
|
|
else if (req_type == NBD_CMD_FLUSH)
|
|
{
|
|
op->opcode = OSD_OP_SYNC;
|
|
buf = malloc_or_die(sizeof(nbd_reply));
|
|
}
|
|
op->callback = [this, buf, handle](cluster_op_t *op)
|
|
{
|
|
#ifdef DEBUG
|
|
printf("reply %lx e=%d\n", handle, op->retval);
|
|
#endif
|
|
nbd_reply *reply = (nbd_reply*)buf;
|
|
reply->magic = htobe32(NBD_REPLY_MAGIC);
|
|
memcpy(reply->handle, &handle, 8);
|
|
reply->error = htobe32(op->retval < 0 ? -op->retval : 0);
|
|
auto & to_list = send_msg.msg_iovlen > 0 ? next_send_list : send_list;
|
|
if (op->retval < 0 || op->opcode != OSD_OP_READ)
|
|
to_list.push_back({ .iov_base = buf, .iov_len = sizeof(nbd_reply) });
|
|
else
|
|
to_list.push_back({ .iov_base = buf, .iov_len = sizeof(nbd_reply) + op->len });
|
|
to_free.push_back(buf);
|
|
delete op;
|
|
ringloop->wakeup();
|
|
};
|
|
if (req_type == NBD_CMD_WRITE)
|
|
{
|
|
cur_op = op;
|
|
cur_buf = buf + sizeof(nbd_reply);
|
|
cur_left = op->len;
|
|
read_state = CL_READ_DATA;
|
|
}
|
|
else
|
|
{
|
|
cur_op = NULL;
|
|
cur_buf = &cur_req;
|
|
cur_left = sizeof(nbd_request);
|
|
read_state = CL_READ_HDR;
|
|
cli->execute(op);
|
|
}
|
|
}
|
|
else
|
|
{
|
|
cli->execute(cur_op);
|
|
cur_op = NULL;
|
|
cur_buf = &cur_req;
|
|
cur_left = sizeof(nbd_request);
|
|
read_state = CL_READ_HDR;
|
|
}
|
|
}
|
|
};
|
|
|
|
int main(int narg, const char *args[])
|
|
{
|
|
setvbuf(stdout, NULL, _IONBF, 0);
|
|
setvbuf(stderr, NULL, _IONBF, 0);
|
|
exe_name = args[0];
|
|
nbd_proxy *p = new nbd_proxy();
|
|
p->exec(nbd_proxy::parse_args(narg, args));
|
|
return 0;
|
|
}
|