diff options
Diffstat (limited to 'nbd.c')
| -rw-r--r-- | nbd.c | 290 |
1 files changed, 212 insertions, 78 deletions
@@ -1,4 +1,4 @@ -/*\ +/* * Copyright (C) 2005 Anthony Liguori <anthony@codemonkey.ws> * * Network Block Device @@ -15,7 +15,7 @@ * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA -\*/ + */ #include "nbd.h" @@ -25,22 +25,27 @@ #include <ctype.h> #include <inttypes.h> #include <sys/socket.h> +#include <sys/un.h> #include <netinet/in.h> #include <netinet/tcp.h> #include <arpa/inet.h> #include <netdb.h> +#if defined(QEMU_NBD) extern int verbose; +#else +static int verbose = 0; +#endif + +#define TRACE(msg, ...) do { \ + if (verbose) LOG(msg, ## __VA_ARGS__); \ +} while(0) #define LOG(msg, ...) do { \ fprintf(stderr, "%s:%s():L%d: " msg "\n", \ __FILE__, __FUNCTION__, __LINE__, ## __VA_ARGS__); \ } while(0) -#define TRACE(msg, ...) do { \ - if (verbose) LOG(msg, ## __VA_ARGS__); \ -} while(0) - /* This is all part of the "official" NBD API */ #define NBD_REQUEST_MAGIC 0x25609513 @@ -58,10 +63,10 @@ extern int verbose; /* That's all folks */ -#define read_sync(fd, buffer, size) wr_sync(fd, buffer, size, true) -#define write_sync(fd, buffer, size) wr_sync(fd, buffer, size, false) +#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) -static size_t wr_sync(int fd, void *buffer, size_t size, bool do_read) +size_t nbd_wr_sync(int fd, void *buffer, size_t size, bool do_read) { size_t offset = 0; @@ -75,7 +80,7 @@ static size_t wr_sync(int fd, void *buffer, size_t size, bool do_read) } /* recoverable error */ - if (len == -1 && errno == EAGAIN) { + if (len == -1 && (errno == EAGAIN || errno == EINTR)) { continue; } @@ -95,7 +100,7 @@ static size_t wr_sync(int fd, void *buffer, size_t size, bool do_read) return offset; } -static int tcp_socket_outgoing(const char *address, uint16_t port) +int tcp_socket_outgoing(const char *address, uint16_t port) { int s; struct in_addr in; @@ -183,6 +188,65 @@ error: return -1; } +int unix_socket_incoming(const char *path) +{ + int s; + struct sockaddr_un addr; + int serrno; + + 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: + serrno = errno; + close(s); + errno = serrno; + return -1; +} + +int unix_socket_outgoing(const char *path) +{ + int s; + struct sockaddr_un addr; + int serrno; + + 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: + serrno = errno; + close(s); + errno = serrno; + return -1; +} + + /* Basic flow Server Client @@ -225,12 +289,10 @@ int nbd_negotiate(BlockDriverState *bs, int csock, off_t size) return 0; } -int nbd_receive_negotiate(int fd, int csock) +int nbd_receive_negotiate(int csock, off_t *size, size_t *blocksize) { char buf[8 + 8 + 8 + 128]; uint64_t magic; - off_t size; - size_t blocksize; TRACE("Receiving negotation."); @@ -241,8 +303,8 @@ int nbd_receive_negotiate(int fd, int csock) } magic = be64_to_cpup((uint64_t*)(buf + 8)); - size = be64_to_cpup((uint64_t*)(buf + 16)); - blocksize = 1024; + *size = be64_to_cpup((uint64_t*)(buf + 16)); + *blocksize = 1024; TRACE("Magic is %c%c%c%c%c%c%c%c", isprint(buf[0]) ? buf[0] : '.', @@ -254,7 +316,7 @@ int nbd_receive_negotiate(int fd, int csock) isprint(buf[6]) ? buf[6] : '.', isprint(buf[7]) ? buf[7] : '.'); TRACE("Magic is 0x%" PRIx64, magic); - TRACE("Size is %" PRIu64, size); + TRACE("Size is %" PRIu64, *size); if (memcmp(buf, "NBDMAGIC", 8) != 0) { LOG("Invalid magic received"); @@ -269,7 +331,11 @@ int nbd_receive_negotiate(int fd, int csock) errno = EINVAL; return -1; } + return 0; +} +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) { @@ -342,20 +408,31 @@ int nbd_client(int fd, int csock) return ret; } -int nbd_trip(BlockDriverState *bs, int csock, off_t size, uint64_t dev_offset, off_t *offset, bool readonly) +int nbd_send_request(int csock, struct nbd_request *request) { -#ifndef _REENTRANT - static uint8_t data[1024 * 1024]; // keep this off of the stack -#else - uint8_t data[1024 * 1024]; -#endif uint8_t buf[4 + 4 + 8 + 8 + 4]; - uint32_t magic; - uint32_t type; - uint64_t from; - uint32_t len; - TRACE("Reading request."); + 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"); @@ -364,97 +441,159 @@ int nbd_trip(BlockDriverState *bs, int csock, off_t size, uint64_t dev_offset, o } /* Request - [ 0 .. 3] magic (NBD_REQUEST_MAGIC) - [ 4 .. 7] type (0 == READ, 1 == WRITE) - [ 8 .. 15] handle - [16 .. 23] from - [24 .. 27] len + [ 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); - type = be32_to_cpup((uint32_t*)(buf + 4)); - from = be64_to_cpup((uint64_t*)(buf + 16)); - len = be32_to_cpup((uint32_t*)(buf + 24)); + 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, type, from, len); - + 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[4 + 4 + 8]; + 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 (len > sizeof(data)) { + if (request.len > data_size) { LOG("len (%u) is larger than max len (%u)", - len, sizeof(data)); + request.len, data_size); errno = EINVAL; return -1; } - if ((from + len) < from) { + if ((request.from + request.len) < request.from) { LOG("integer overflow detected! " "you're probably being attacked"); errno = EINVAL; return -1; } - if ((from + len) > size) { + if ((request.from + request.len) > size) { LOG("From: %" PRIu64 ", Len: %u, Size: %" PRIu64 ", Offset: %" PRIu64 "\n", - from, len, size, dev_offset); + request.from, request.len, size, dev_offset); LOG("requested operation past EOF--bad client?"); errno = EINVAL; return -1; } - /* 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), 0); - TRACE("Decoding type"); - switch (type) { - case 0: + reply.handle = request.handle; + reply.error = 0; + + switch (request.type) { + case NBD_CMD_READ: TRACE("Request type is READ"); - if (bdrv_read(bs, (from + dev_offset) / 512, data, len / 512) == -1) { + if (bdrv_read(bs, (request.from + dev_offset) / 512, data, + request.len / 512) == -1) { LOG("reading from file failed"); errno = EINVAL; return -1; } - *offset += len; - - TRACE("Read %u byte(s)", len); + *offset += request.len; - TRACE("Sending OK response"); + TRACE("Read %u byte(s)", request.len); - if (write_sync(csock, buf, 16) != 16) { - LOG("writing to socket failed"); - errno = EINVAL; + if (nbd_send_reply(csock, &reply) == -1) return -1; - } TRACE("Sending data to client"); - if (write_sync(csock, data, len) != len) { + if (write_sync(csock, data, request.len) != request.len) { LOG("writing to socket failed"); errno = EINVAL; return -1; } break; - case 1: + case NBD_CMD_WRITE: TRACE("Request type is WRITE"); - TRACE("Reading %u byte(s)", len); + TRACE("Reading %u byte(s)", request.len); - if (read_sync(csock, data, len) != len) { + if (read_sync(csock, data, request.len) != request.len) { LOG("reading from socket failed"); errno = EINVAL; return -1; @@ -462,34 +601,29 @@ int nbd_trip(BlockDriverState *bs, int csock, off_t size, uint64_t dev_offset, o if (readonly) { TRACE("Server is read-only, return error"); - - cpu_to_be32w((uint32_t*)(buf + 4), 1); + reply.error = 1; } else { TRACE("Writing to device"); - if (bdrv_write(bs, (from + dev_offset) / 512, data, len / 512) == -1) { + if (bdrv_write(bs, (request.from + dev_offset) / 512, + data, request.len / 512) == -1) { LOG("writing to file failed"); errno = EINVAL; return -1; } - *offset += len; + *offset += request.len; } - TRACE("Sending response to client"); - - if (write_sync(csock, buf, 16) != 16) { - LOG("writing to socket failed"); - errno = EINVAL; + if (nbd_send_reply(csock, &reply) == -1) return -1; - } break; - case 2: + case NBD_CMD_DISC: TRACE("Request type is DISCONNECT"); errno = 0; return 1; default: - LOG("invalid request type (%u) received", type); + LOG("invalid request type (%u) received", request.type); errno = EINVAL; return -1; } |