From 68396ea9c0fe4f75ce30b1eba2c44c43c13344bb Mon Sep 17 00:00:00 2001 From: Robert Mustacchi Date: Fri, 24 Jun 2011 13:49:54 -0700 Subject: Initial commit of d32e8d0b8d9e0ef7cf7ab2e74548982972789dfc from qemu-kvm --- nbd.c | 765 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 765 insertions(+) create mode 100644 nbd.c (limited to 'nbd.c') 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 + * + * 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 . + */ + +#include "nbd.h" + +#include +#include +#ifndef _WIN32 +#include +#endif +#if defined(__sun__) || defined(__HAIKU__) +#include +#endif +#include +#include + +#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; +} -- cgit v1.2.3