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author | Laurent Vivier <laurent@vivier.eu> | 2010-08-25 22:48:33 +0200 |
---|---|---|
committer | Kevin Wolf <kwolf@redhat.com> | 2010-08-30 18:29:22 +0200 |
commit | 1d45f8b542f6b80b24c44533ef0dd9e1a3b17ea5 (patch) | |
tree | a94959416cdcfc3d9317d31e1026533563a59c79 /nbd.c | |
parent | 2aa326be0d2039f51192707bdb2fc935d0e87c21 (diff) | |
download | qemu-1d45f8b542f6b80b24c44533ef0dd9e1a3b17ea5.zip qemu-1d45f8b542f6b80b24c44533ef0dd9e1a3b17ea5.tar.gz qemu-1d45f8b542f6b80b24c44533ef0dd9e1a3b17ea5.tar.bz2 |
nbd: Introduce NBD named exports.
This patch allows to connect Qemu using NBD protocol to an nbd-server
using named exports.
For instance, if on the host "isoserver", in /etc/nbd-server/config, you have:
[generic]
[debian-500-ppc-netinst]
exportname = /ISO/debian-500-powerpc-netinst.iso
[Fedora-10-ppc-netinst]
exportname = /ISO/Fedora-10-ppc-netinst.iso
You can connect to it, using:
qemu -cdrom nbd:isoserver:exportname=debian-500-ppc-netinst
qemu -cdrom nbd:isoserver:exportname=Fedora-10-ppc-netinst
NOTE: you need at least nbd-server 2.9.18
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Diffstat (limited to 'nbd.c')
-rw-r--r-- | nbd.c | 118 |
1 files changed, 106 insertions, 12 deletions
@@ -62,6 +62,8 @@ #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) @@ -296,22 +298,27 @@ int nbd_negotiate(int csock, off_t size) return 0; } -int nbd_receive_negotiate(int csock, off_t *size, size_t *blocksize) +int nbd_receive_negotiate(int csock, const char *name, uint32_t *flags, + off_t *size, size_t *blocksize) { - char buf[8 + 8 + 8 + 128]; - uint64_t magic; + char buf[256]; + uint64_t magic, s; + uint16_t tmp; TRACE("Receiving negotation."); - if (read_sync(csock, buf, sizeof(buf)) != sizeof(buf)) { + if (read_sync(csock, buf, 8) != 8) { LOG("read failed"); errno = EINVAL; return -1; } - magic = be64_to_cpup((uint64_t*)(buf + 8)); - *size = be64_to_cpup((uint64_t*)(buf + 16)); - *blocksize = 1024; + 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] : '.', @@ -322,8 +329,6 @@ int nbd_receive_negotiate(int csock, off_t *size, size_t *blocksize) qemu_isprint(buf[5]) ? buf[5] : '.', qemu_isprint(buf[6]) ? buf[6] : '.', qemu_isprint(buf[7]) ? buf[7] : '.'); - TRACE("Magic is 0x%" PRIx64, magic); - TRACE("Size is %" PRIu64, *size); if (memcmp(buf, "NBDMAGIC", 8) != 0) { LOG("Invalid magic received"); @@ -331,10 +336,99 @@ int nbd_receive_negotiate(int csock, off_t *size, size_t *blocksize) return -1; } - TRACE("Checking magic"); + 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 (magic != 0x00420281861253LL) { - LOG("Bad magic received"); + 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; } |