Initial commit of d32e8d0b8d9e0ef7cf7ab2e74548982972789dfc from qemu-kvm

1 files changed, 765 insertions, 0 deletions

diff --git a/nbd.c b/nbd.c
new file mode 100644
index 0000000..d8ebc42
--- /dev/null
+++ b/nbd.c
@@ -0,0 +1,765 @@
+/*
+ *  Copyright (C) 2005  Anthony Liguori <anthony@codemonkey.ws>
+ *
+ *  Network Block Device
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; under version 2 of the License.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program; if not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "nbd.h"
+
+#include <errno.h>
+#include <string.h>
+#ifndef _WIN32
+#include <sys/ioctl.h>
+#endif
+#if defined(__sun__) || defined(__HAIKU__)
+#include <sys/ioccom.h>
+#endif
+#include <ctype.h>
+#include <inttypes.h>
+
+#include "qemu_socket.h"
+
+//#define DEBUG_NBD
+
+#ifdef DEBUG_NBD
+#define TRACE(msg, ...) do { \
+    LOG(msg, ## __VA_ARGS__); \
+} while(0)
+#else
+#define TRACE(msg, ...) \
+    do { } while (0)
+#endif
+
+#define LOG(msg, ...) do { \
+    fprintf(stderr, "%s:%s():L%d: " msg "\n", \
+            __FILE__, __FUNCTION__, __LINE__, ## __VA_ARGS__); \
+} while(0)
+
+/* This is all part of the "official" NBD API */
+
+#define NBD_REPLY_SIZE		(4 + 4 + 8)
+#define NBD_REQUEST_MAGIC       0x25609513
+#define NBD_REPLY_MAGIC         0x67446698
+
+#define NBD_SET_SOCK            _IO(0xab, 0)
+#define NBD_SET_BLKSIZE         _IO(0xab, 1)
+#define NBD_SET_SIZE            _IO(0xab, 2)
+#define NBD_DO_IT               _IO(0xab, 3)
+#define NBD_CLEAR_SOCK          _IO(0xab, 4)
+#define NBD_CLEAR_QUE           _IO(0xab, 5)
+#define NBD_PRINT_DEBUG	        _IO(0xab, 6)
+#define NBD_SET_SIZE_BLOCKS	_IO(0xab, 7)
+#define NBD_DISCONNECT          _IO(0xab, 8)
+
+#define NBD_OPT_EXPORT_NAME	(1 << 0)
+
+/* That's all folks */
+
+#define read_sync(fd, buffer, size) nbd_wr_sync(fd, buffer, size, true)
+#define write_sync(fd, buffer, size) nbd_wr_sync(fd, buffer, size, false)
+
+size_t nbd_wr_sync(int fd, void *buffer, size_t size, bool do_read)
+{
+    size_t offset = 0;
+
+    while (offset < size) {
+        ssize_t len;
+
+        if (do_read) {
+            len = recv(fd, buffer + offset, size - offset, 0);
+        } else {
+            len = send(fd, buffer + offset, size - offset, 0);
+        }
+
+        if (len == -1)
+            errno = socket_error();
+
+        /* recoverable error */
+        if (len == -1 && (errno == EAGAIN || errno == EINTR)) {
+            continue;
+        }
+
+        /* eof */
+        if (len == 0) {
+            break;
+        }
+
+        /* unrecoverable error */
+        if (len == -1) {
+            return 0;
+        }
+
+        offset += len;
+    }
+
+    return offset;
+}
+
+int tcp_socket_outgoing(const char *address, uint16_t port)
+{
+    int s;
+    struct in_addr in;
+    struct sockaddr_in addr;
+
+    s = socket(PF_INET, SOCK_STREAM, 0);
+    if (s == -1) {
+        return -1;
+    }
+
+    if (inet_aton(address, &in) == 0) {
+        struct hostent *ent;
+
+        ent = gethostbyname(address);
+        if (ent == NULL) {
+            goto error;
+        }
+
+        memcpy(&in, ent->h_addr, sizeof(in));
+    }
+
+    addr.sin_family = AF_INET;
+    addr.sin_port = htons(port);
+    memcpy(&addr.sin_addr.s_addr, &in, sizeof(in));
+
+    if (connect(s, (struct sockaddr *)&addr, sizeof(addr)) == -1) {
+        goto error;
+    }
+
+    return s;
+error:
+    closesocket(s);
+    return -1;
+}
+
+int tcp_socket_incoming(const char *address, uint16_t port)
+{
+    int s;
+    struct in_addr in;
+    struct sockaddr_in addr;
+    int opt;
+
+    s = socket(PF_INET, SOCK_STREAM, 0);
+    if (s == -1) {
+        return -1;
+    }
+
+    if (inet_aton(address, &in) == 0) {
+        struct hostent *ent;
+
+        ent = gethostbyname(address);
+        if (ent == NULL) {
+            goto error;
+        }
+
+        memcpy(&in, ent->h_addr, sizeof(in));
+    }
+
+    addr.sin_family = AF_INET;
+    addr.sin_port = htons(port);
+    memcpy(&addr.sin_addr.s_addr, &in, sizeof(in));
+
+    opt = 1;
+    if (setsockopt(s, SOL_SOCKET, SO_REUSEADDR,
+                   (const void *) &opt, sizeof(opt)) == -1) {
+        goto error;
+    }
+
+    if (bind(s, (struct sockaddr *)&addr, sizeof(addr)) == -1) {
+        goto error;
+    }
+
+    if (listen(s, 128) == -1) {
+        goto error;
+    }
+
+    return s;
+error:
+    closesocket(s);
+    return -1;
+}
+
+#ifndef _WIN32
+int unix_socket_incoming(const char *path)
+{
+    int s;
+    struct sockaddr_un addr;
+
+    s = socket(PF_UNIX, SOCK_STREAM, 0);
+    if (s == -1) {
+        return -1;
+    }
+
+    memset(&addr, 0, sizeof(addr));
+    addr.sun_family = AF_UNIX;
+    pstrcpy(addr.sun_path, sizeof(addr.sun_path), path);
+
+    if (bind(s, (struct sockaddr *)&addr, sizeof(addr)) == -1) {
+        goto error;
+    }
+
+    if (listen(s, 128) == -1) {
+        goto error;
+    }
+
+    return s;
+error:
+    closesocket(s);
+    return -1;
+}
+
+int unix_socket_outgoing(const char *path)
+{
+    int s;
+    struct sockaddr_un addr;
+
+    s = socket(PF_UNIX, SOCK_STREAM, 0);
+    if (s == -1) {
+        return -1;
+    }
+
+    memset(&addr, 0, sizeof(addr));
+    addr.sun_family = AF_UNIX;
+    pstrcpy(addr.sun_path, sizeof(addr.sun_path), path);
+
+    if (connect(s, (struct sockaddr *)&addr, sizeof(addr)) == -1) {
+        goto error;
+    }
+
+    return s;
+error:
+    closesocket(s);
+    return -1;
+}
+#else
+int unix_socket_incoming(const char *path)
+{
+    errno = ENOTSUP;
+    return -1;
+}
+
+int unix_socket_outgoing(const char *path)
+{
+    errno = ENOTSUP;
+    return -1;
+}
+#endif
+
+
+/* Basic flow
+
+   Server         Client
+
+   Negotiate
+                  Request
+   Response
+                  Request
+   Response
+                  ...
+   ...
+                  Request (type == 2)
+*/
+
+int nbd_negotiate(int csock, off_t size)
+{
+	char buf[8 + 8 + 8 + 128];
+
+	/* Negotiate
+	   [ 0 ..   7]   passwd   ("NBDMAGIC")
+	   [ 8 ..  15]   magic    (0x00420281861253)
+	   [16 ..  23]   size
+	   [24 .. 151]   reserved (0)
+	 */
+
+	TRACE("Beginning negotiation.");
+	memcpy(buf, "NBDMAGIC", 8);
+	cpu_to_be64w((uint64_t*)(buf + 8), 0x00420281861253LL);
+	cpu_to_be64w((uint64_t*)(buf + 16), size);
+	memset(buf + 24, 0, 128);
+
+	if (write_sync(csock, buf, sizeof(buf)) != sizeof(buf)) {
+		LOG("write failed");
+		errno = EINVAL;
+		return -1;
+	}
+
+	TRACE("Negotation succeeded.");
+
+	return 0;
+}
+
+int nbd_receive_negotiate(int csock, const char *name, uint32_t *flags,
+                          off_t *size, size_t *blocksize)
+{
+	char buf[256];
+	uint64_t magic, s;
+	uint16_t tmp;
+
+	TRACE("Receiving negotation.");
+
+	if (read_sync(csock, buf, 8) != 8) {
+		LOG("read failed");
+		errno = EINVAL;
+		return -1;
+	}
+
+	buf[8] = '\0';
+	if (strlen(buf) == 0) {
+		LOG("server connection closed");
+		errno = EINVAL;
+		return -1;
+	}
+
+	TRACE("Magic is %c%c%c%c%c%c%c%c",
+	      qemu_isprint(buf[0]) ? buf[0] : '.',
+	      qemu_isprint(buf[1]) ? buf[1] : '.',
+	      qemu_isprint(buf[2]) ? buf[2] : '.',
+	      qemu_isprint(buf[3]) ? buf[3] : '.',
+	      qemu_isprint(buf[4]) ? buf[4] : '.',
+	      qemu_isprint(buf[5]) ? buf[5] : '.',
+	      qemu_isprint(buf[6]) ? buf[6] : '.',
+	      qemu_isprint(buf[7]) ? buf[7] : '.');
+
+	if (memcmp(buf, "NBDMAGIC", 8) != 0) {
+		LOG("Invalid magic received");
+		errno = EINVAL;
+		return -1;
+	}
+
+	if (read_sync(csock, &magic, sizeof(magic)) != sizeof(magic)) {
+		LOG("read failed");
+		errno = EINVAL;
+		return -1;
+	}
+	magic = be64_to_cpu(magic);
+	TRACE("Magic is 0x%" PRIx64, magic);
+
+	if (name) {
+		uint32_t reserved = 0;
+		uint32_t opt;
+		uint32_t namesize;
+
+		TRACE("Checking magic (opts_magic)");
+		if (magic != 0x49484156454F5054LL) {
+			LOG("Bad magic received");
+			errno = EINVAL;
+			return -1;
+		}
+		if (read_sync(csock, &tmp, sizeof(tmp)) != sizeof(tmp)) {
+			LOG("flags read failed");
+			errno = EINVAL;
+			return -1;
+		}
+		*flags = be16_to_cpu(tmp) << 16;
+		/* reserved for future use */
+		if (write_sync(csock, &reserved, sizeof(reserved)) !=
+		    sizeof(reserved)) {
+			LOG("write failed (reserved)");
+			errno = EINVAL;
+			return -1;
+		}
+		/* write the export name */
+		magic = cpu_to_be64(magic);
+		if (write_sync(csock, &magic, sizeof(magic)) != sizeof(magic)) {
+			LOG("write failed (magic)");
+			errno = EINVAL;
+			return -1;
+		}
+		opt = cpu_to_be32(NBD_OPT_EXPORT_NAME);
+		if (write_sync(csock, &opt, sizeof(opt)) != sizeof(opt)) {
+			LOG("write failed (opt)");
+			errno = EINVAL;
+			return -1;
+		}
+		namesize = cpu_to_be32(strlen(name));
+		if (write_sync(csock, &namesize, sizeof(namesize)) !=
+		    sizeof(namesize)) {
+			LOG("write failed (namesize)");
+			errno = EINVAL;
+			return -1;
+		}
+		if (write_sync(csock, (char*)name, strlen(name)) != strlen(name)) {
+			LOG("write failed (name)");
+			errno = EINVAL;
+			return -1;
+		}
+	} else {
+		TRACE("Checking magic (cli_magic)");
+
+		if (magic != 0x00420281861253LL) {
+			LOG("Bad magic received");
+			errno = EINVAL;
+			return -1;
+		}
+	}
+
+	if (read_sync(csock, &s, sizeof(s)) != sizeof(s)) {
+		LOG("read failed");
+		errno = EINVAL;
+		return -1;
+	}
+	*size = be64_to_cpu(s);
+	*blocksize = 1024;
+	TRACE("Size is %" PRIu64, *size);
+
+	if (!name) {
+		if (read_sync(csock, flags, sizeof(*flags)) != sizeof(*flags)) {
+			LOG("read failed (flags)");
+			errno = EINVAL;
+			return -1;
+		}
+		*flags = be32_to_cpup(flags);
+	} else {
+		if (read_sync(csock, &tmp, sizeof(tmp)) != sizeof(tmp)) {
+			LOG("read failed (tmp)");
+			errno = EINVAL;
+			return -1;
+		}
+		*flags |= be32_to_cpu(tmp);
+	}
+	if (read_sync(csock, &buf, 124) != 124) {
+		LOG("read failed (buf)");
+		errno = EINVAL;
+		return -1;
+	}
+        return 0;
+}
+
+#ifndef _WIN32
+int nbd_init(int fd, int csock, off_t size, size_t blocksize)
+{
+	TRACE("Setting block size to %lu", (unsigned long)blocksize);
+
+	if (ioctl(fd, NBD_SET_BLKSIZE, blocksize) == -1) {
+		int serrno = errno;
+		LOG("Failed setting NBD block size");
+		errno = serrno;
+		return -1;
+	}
+
+        TRACE("Setting size to %zd block(s)", (size_t)(size / blocksize));
+
+	if (ioctl(fd, NBD_SET_SIZE_BLOCKS, size / blocksize) == -1) {
+		int serrno = errno;
+		LOG("Failed setting size (in blocks)");
+		errno = serrno;
+		return -1;
+	}
+
+	TRACE("Clearing NBD socket");
+
+	if (ioctl(fd, NBD_CLEAR_SOCK) == -1) {
+		int serrno = errno;
+		LOG("Failed clearing NBD socket");
+		errno = serrno;
+		return -1;
+	}
+
+	TRACE("Setting NBD socket");
+
+	if (ioctl(fd, NBD_SET_SOCK, csock) == -1) {
+		int serrno = errno;
+		LOG("Failed to set NBD socket");
+		errno = serrno;
+		return -1;
+	}
+
+	TRACE("Negotiation ended");
+
+	return 0;
+}
+
+int nbd_disconnect(int fd)
+{
+	ioctl(fd, NBD_CLEAR_QUE);
+	ioctl(fd, NBD_DISCONNECT);
+	ioctl(fd, NBD_CLEAR_SOCK);
+	return 0;
+}
+
+int nbd_client(int fd)
+{
+	int ret;
+	int serrno;
+
+	TRACE("Doing NBD loop");
+
+	ret = ioctl(fd, NBD_DO_IT);
+	serrno = errno;
+
+	TRACE("NBD loop returned %d: %s", ret, strerror(serrno));
+
+	TRACE("Clearing NBD queue");
+	ioctl(fd, NBD_CLEAR_QUE);
+
+	TRACE("Clearing NBD socket");
+	ioctl(fd, NBD_CLEAR_SOCK);
+
+	errno = serrno;
+	return ret;
+}
+#else
+int nbd_init(int fd, int csock, off_t size, size_t blocksize)
+{
+    errno = ENOTSUP;
+    return -1;
+}
+
+int nbd_disconnect(int fd)
+{
+    errno = ENOTSUP;
+    return -1;
+}
+
+int nbd_client(int fd)
+{
+    errno = ENOTSUP;
+    return -1;
+}
+#endif
+
+int nbd_send_request(int csock, struct nbd_request *request)
+{
+	uint8_t buf[4 + 4 + 8 + 8 + 4];
+
+	cpu_to_be32w((uint32_t*)buf, NBD_REQUEST_MAGIC);
+	cpu_to_be32w((uint32_t*)(buf + 4), request->type);
+	cpu_to_be64w((uint64_t*)(buf + 8), request->handle);
+	cpu_to_be64w((uint64_t*)(buf + 16), request->from);
+	cpu_to_be32w((uint32_t*)(buf + 24), request->len);
+
+	TRACE("Sending request to client");
+
+	if (write_sync(csock, buf, sizeof(buf)) != sizeof(buf)) {
+		LOG("writing to socket failed");
+		errno = EINVAL;
+		return -1;
+	}
+	return 0;
+}
+
+
+static int nbd_receive_request(int csock, struct nbd_request *request)
+{
+	uint8_t buf[4 + 4 + 8 + 8 + 4];
+	uint32_t magic;
+
+	if (read_sync(csock, buf, sizeof(buf)) != sizeof(buf)) {
+		LOG("read failed");
+		errno = EINVAL;
+		return -1;
+	}
+
+	/* Request
+	   [ 0 ..  3]   magic   (NBD_REQUEST_MAGIC)
+	   [ 4 ..  7]   type    (0 == READ, 1 == WRITE)
+	   [ 8 .. 15]   handle
+	   [16 .. 23]   from
+	   [24 .. 27]   len
+	 */
+
+	magic = be32_to_cpup((uint32_t*)buf);
+	request->type  = be32_to_cpup((uint32_t*)(buf + 4));
+	request->handle = be64_to_cpup((uint64_t*)(buf + 8));
+	request->from  = be64_to_cpup((uint64_t*)(buf + 16));
+	request->len   = be32_to_cpup((uint32_t*)(buf + 24));
+
+	TRACE("Got request: "
+	      "{ magic = 0x%x, .type = %d, from = %" PRIu64" , len = %u }",
+	      magic, request->type, request->from, request->len);
+
+	if (magic != NBD_REQUEST_MAGIC) {
+		LOG("invalid magic (got 0x%x)", magic);
+		errno = EINVAL;
+		return -1;
+	}
+	return 0;
+}
+
+int nbd_receive_reply(int csock, struct nbd_reply *reply)
+{
+	uint8_t buf[NBD_REPLY_SIZE];
+	uint32_t magic;
+
+	memset(buf, 0xAA, sizeof(buf));
+
+	if (read_sync(csock, buf, sizeof(buf)) != sizeof(buf)) {
+		LOG("read failed");
+		errno = EINVAL;
+		return -1;
+	}
+
+	/* Reply
+	   [ 0 ..  3]    magic   (NBD_REPLY_MAGIC)
+	   [ 4 ..  7]    error   (0 == no error)
+	   [ 7 .. 15]    handle
+	 */
+
+	magic = be32_to_cpup((uint32_t*)buf);
+	reply->error  = be32_to_cpup((uint32_t*)(buf + 4));
+	reply->handle = be64_to_cpup((uint64_t*)(buf + 8));
+
+	TRACE("Got reply: "
+	      "{ magic = 0x%x, .error = %d, handle = %" PRIu64" }",
+	      magic, reply->error, reply->handle);
+
+	if (magic != NBD_REPLY_MAGIC) {
+		LOG("invalid magic (got 0x%x)", magic);
+		errno = EINVAL;
+		return -1;
+	}
+	return 0;
+}
+
+static int nbd_send_reply(int csock, struct nbd_reply *reply)
+{
+	uint8_t buf[4 + 4 + 8];
+
+	/* Reply
+	   [ 0 ..  3]    magic   (NBD_REPLY_MAGIC)
+	   [ 4 ..  7]    error   (0 == no error)
+	   [ 7 .. 15]    handle
+	 */
+	cpu_to_be32w((uint32_t*)buf, NBD_REPLY_MAGIC);
+	cpu_to_be32w((uint32_t*)(buf + 4), reply->error);
+	cpu_to_be64w((uint64_t*)(buf + 8), reply->handle);
+
+	TRACE("Sending response to client");
+
+	if (write_sync(csock, buf, sizeof(buf)) != sizeof(buf)) {
+		LOG("writing to socket failed");
+		errno = EINVAL;
+		return -1;
+	}
+	return 0;
+}
+
+int nbd_trip(BlockDriverState *bs, int csock, off_t size, uint64_t dev_offset,
+             off_t *offset, bool readonly, uint8_t *data, int data_size)
+{
+	struct nbd_request request;
+	struct nbd_reply reply;
+
+	TRACE("Reading request.");
+
+	if (nbd_receive_request(csock, &request) == -1)
+		return -1;
+
+	if (request.len + NBD_REPLY_SIZE > data_size) {
+		LOG("len (%u) is larger than max len (%u)",
+		    request.len + NBD_REPLY_SIZE, data_size);
+		errno = EINVAL;
+		return -1;
+	}
+
+	if ((request.from + request.len) < request.from) {
+		LOG("integer overflow detected! "
+		    "you're probably being attacked");
+		errno = EINVAL;
+		return -1;
+	}
+
+	if ((request.from + request.len) > size) {
+	        LOG("From: %" PRIu64 ", Len: %u, Size: %" PRIu64
+		    ", Offset: %" PRIu64 "\n",
+                    request.from, request.len, (uint64_t)size, dev_offset);
+		LOG("requested operation past EOF--bad client?");
+		errno = EINVAL;
+		return -1;
+	}
+
+	TRACE("Decoding type");
+
+	reply.handle = request.handle;
+	reply.error = 0;
+
+	switch (request.type) {
+	case NBD_CMD_READ:
+		TRACE("Request type is READ");
+
+		if (bdrv_read(bs, (request.from + dev_offset) / 512,
+			      data + NBD_REPLY_SIZE,
+			      request.len / 512) == -1) {
+			LOG("reading from file failed");
+			errno = EINVAL;
+			return -1;
+		}
+		*offset += request.len;
+
+		TRACE("Read %u byte(s)", request.len);
+
+		/* Reply
+		   [ 0 ..  3]    magic   (NBD_REPLY_MAGIC)
+		   [ 4 ..  7]    error   (0 == no error)
+		   [ 7 .. 15]    handle
+		 */
+
+		cpu_to_be32w((uint32_t*)data, NBD_REPLY_MAGIC);
+		cpu_to_be32w((uint32_t*)(data + 4), reply.error);
+		cpu_to_be64w((uint64_t*)(data + 8), reply.handle);
+
+		TRACE("Sending data to client");
+
+		if (write_sync(csock, data,
+			       request.len + NBD_REPLY_SIZE) !=
+			       request.len + NBD_REPLY_SIZE) {
+			LOG("writing to socket failed");
+			errno = EINVAL;
+			return -1;
+		}
+		break;
+	case NBD_CMD_WRITE:
+		TRACE("Request type is WRITE");
+
+		TRACE("Reading %u byte(s)", request.len);
+
+		if (read_sync(csock, data, request.len) != request.len) {
+			LOG("reading from socket failed");
+			errno = EINVAL;
+			return -1;
+		}
+
+		if (readonly) {
+			TRACE("Server is read-only, return error");
+			reply.error = 1;
+		} else {
+			TRACE("Writing to device");
+
+			if (bdrv_write(bs, (request.from + dev_offset) / 512,
+				       data, request.len / 512) == -1) {
+				LOG("writing to file failed");
+				errno = EINVAL;
+				return -1;
+			}
+
+			*offset += request.len;
+		}
+
+		if (nbd_send_reply(csock, &reply) == -1)
+			return -1;
+		break;
+	case NBD_CMD_DISC:
+		TRACE("Request type is DISCONNECT");
+		errno = 0;
+		return 1;
+	default:
+		LOG("invalid request type (%u) received", request.type);
+		errno = EINVAL;
+		return -1;
+	}
+
+	TRACE("Request/Reply complete");
+
+	return 0;
+}