static int nbd_send_negotiate(NBDClient *client) { int csock = client->sock; char buf[8 + 8 + 8 + 128]; int rc; const int myflags = (NBD_FLAG_HAS_FLAGS | NBD_FLAG_SEND_TRIM | NBD_FLAG_SEND_FLUSH | NBD_FLAG_SEND_FUA); /* Negotiation header without options: [ 0 .. 7] passwd ("NBDMAGIC") [ 8 .. 15] magic (NBD_CLIENT_MAGIC) [16 .. 23] size [24 .. 25] server flags (0) [26 .. 27] export flags [28 .. 151] reserved (0) Negotiation header with options, part 1: [ 0 .. 7] passwd ("NBDMAGIC") [ 8 .. 15] magic (NBD_OPTS_MAGIC) [16 .. 17] server flags (0) part 2 (after options are sent): [18 .. 25] size [26 .. 27] export flags [28 .. 151] reserved (0) */ qemu_set_block(csock); rc = -EINVAL; TRACE("Beginning negotiation."); memset(buf, 0, sizeof(buf)); memcpy(buf, "NBDMAGIC", 8); if (client->exp) { assert ((client->exp->nbdflags & ~65535) == 0); cpu_to_be64w((uint64_t*)(buf + 8), NBD_CLIENT_MAGIC); cpu_to_be64w((uint64_t*)(buf + 16), client->exp->size); cpu_to_be16w((uint16_t*)(buf + 26), client->exp->nbdflags | myflags); } else { cpu_to_be64w((uint64_t*)(buf + 8), NBD_OPTS_MAGIC); cpu_to_be16w((uint16_t *)(buf + 16), NBD_FLAG_FIXED_NEWSTYLE); } if (client->exp) { if (write_sync(csock, buf, sizeof(buf)) != sizeof(buf)) { LOG("write failed"); goto fail; } } else { if (write_sync(csock, buf, 18) != 18) { LOG("write failed"); goto fail; } rc = nbd_receive_options(client); if (rc != 0) { LOG("option negotiation failed"); goto fail; } assert ((client->exp->nbdflags & ~65535) == 0); cpu_to_be64w((uint64_t*)(buf + 18), client->exp->size); cpu_to_be16w((uint16_t*)(buf + 26), client->exp->nbdflags | myflags); if (write_sync(csock, buf + 18, sizeof(buf) - 18) != sizeof(buf) - 18) { LOG("write failed"); goto fail; } } TRACE("Negotiation succeeded."); rc = 0; fail: qemu_set_nonblock(csock); return rc; }
static int nbd_send_negotiate(NBDClient *client) { int csock = client->sock; char buf[8 + 8 + 8 + 128]; int rc; const int myflags = (NBD_FLAG_HAS_FLAGS | NBD_FLAG_SEND_TRIM | NBD_FLAG_SEND_FLUSH | NBD_FLAG_SEND_FUA);   qemu_set_block(csock); rc = -EINVAL; TRACE("Beginning negotiation."); memset(buf, 0, sizeof(buf)); memcpy(buf, "NBDMAGIC", 8); if (client->exp) { assert ((client->exp->nbdflags & ~65535) == 0); cpu_to_be64w((uint64_t*)(buf + 8), NBD_CLIENT_MAGIC); cpu_to_be64w((uint64_t*)(buf + 16), client->exp->size); cpu_to_be16w((uint16_t*)(buf + 26), client->exp->nbdflags | myflags); } else { cpu_to_be64w((uint64_t*)(buf + 8), NBD_OPTS_MAGIC); cpu_to_be16w((uint16_t *)(buf + 16), NBD_FLAG_FIXED_NEWSTYLE); } if (client->exp) { if (write_sync(csock, buf, sizeof(buf)) != sizeof(buf)) { LOG("write failed"); goto fail; } } else { if (write_sync(csock, buf, 18) != 18) { LOG("write failed"); goto fail; } rc = nbd_receive_options(client); if (rc != 0) { LOG("option negotiation failed"); goto fail; } assert ((client->exp->nbdflags & ~65535) == 0); cpu_to_be64w((uint64_t*)(buf + 18), client->exp->size); cpu_to_be16w((uint16_t*)(buf + 26), client->exp->nbdflags | myflags); if (write_sync(csock, buf + 18, sizeof(buf) - 18) != sizeof(buf) - 18) { LOG("write failed"); goto fail; } } TRACE("Negotiation succeeded."); rc = 0; fail: qemu_set_nonblock(csock); return rc; }