diff options
Diffstat (limited to 'sys/xen/xenstore/xenstore_dev.c')
| -rw-r--r-- | sys/xen/xenstore/xenstore_dev.c | 224 |
1 files changed, 224 insertions, 0 deletions
diff --git a/sys/xen/xenstore/xenstore_dev.c b/sys/xen/xenstore/xenstore_dev.c new file mode 100644 index 0000000..1fa4197 --- /dev/null +++ b/sys/xen/xenstore/xenstore_dev.c @@ -0,0 +1,224 @@ +/* + * xenstore_dev.c + * + * Driver giving user-space access to the kernel's connection to the + * XenStore service. + * + * Copyright (c) 2005, Christian Limpach + * Copyright (c) 2005, Rusty Russell, IBM Corporation + * + * This file may be distributed separately from the Linux kernel, or + * incorporated into other software packages, subject to the following license: + * + * Permission is hereby granted, free of charge, to any person obtaining a copy + * of this source file (the "Software"), to deal in the Software without + * restriction, including without limitation the rights to use, copy, modify, + * merge, publish, distribute, sublicense, and/or sell copies of the Software, + * and to permit persons to whom the Software is furnished to do so, subject to + * the following conditions: + * + * The above copyright notice and this permission notice shall be included in + * all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE + * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING + * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS + * IN THE SOFTWARE. + */ + + +#include <sys/cdefs.h> +__FBSDID("$FreeBSD$"); + +#include <sys/types.h> +#include <sys/cdefs.h> +#include <sys/errno.h> +#include <sys/uio.h> +#include <sys/param.h> +#include <sys/systm.h> +#include <sys/proc.h> +#include <sys/kernel.h> +#include <sys/malloc.h> +#include <sys/conf.h> + +#include <machine/xen/xen-os.h> + +#include <xen/hypervisor.h> +#include <xen/xenstore/xenstorevar.h> +#include <xen/xenstore/xenstore_internal.h> + +struct xs_dev_transaction { + LIST_ENTRY(xs_dev_transaction) list; + struct xs_transaction handle; +}; + +struct xs_dev_data { + /* In-progress transaction. */ + LIST_HEAD(xdd_list_head, xs_dev_transaction) transactions; + + /* Partial request. */ + unsigned int len; + union { + struct xsd_sockmsg msg; + char buffer[PAGE_SIZE]; + } u; + + /* Response queue. */ +#define MASK_READ_IDX(idx) ((idx)&(PAGE_SIZE-1)) + char read_buffer[PAGE_SIZE]; + unsigned int read_cons, read_prod; +}; + +static int +xs_dev_read(struct cdev *dev, struct uio *uio, int ioflag) +{ + int error; + struct xs_dev_data *u = dev->si_drv1; + + while (u->read_prod == u->read_cons) { + error = tsleep(u, PCATCH, "xsdread", hz/10); + if (error && error != EWOULDBLOCK) + return (error); + } + + while (uio->uio_resid > 0) { + if (u->read_cons == u->read_prod) + break; + error = uiomove(&u->read_buffer[MASK_READ_IDX(u->read_cons)], + 1, uio); + if (error) + return (error); + u->read_cons++; + } + return (0); +} + +static void +xs_queue_reply(struct xs_dev_data *u, char *data, unsigned int len) +{ + int i; + + for (i = 0; i < len; i++, u->read_prod++) + u->read_buffer[MASK_READ_IDX(u->read_prod)] = data[i]; + + KASSERT((u->read_prod - u->read_cons) <= sizeof(u->read_buffer), + ("xenstore reply too big")); + + wakeup(u); +} + +static int +xs_dev_write(struct cdev *dev, struct uio *uio, int ioflag) +{ + int error; + struct xs_dev_data *u = dev->si_drv1; + struct xs_dev_transaction *trans; + void *reply; + int len = uio->uio_resid; + + if ((len + u->len) > sizeof(u->u.buffer)) + return (EINVAL); + + error = uiomove(u->u.buffer + u->len, len, uio); + if (error) + return (error); + + u->len += len; + if (u->len < (sizeof(u->u.msg) + u->u.msg.len)) + return (0); + + switch (u->u.msg.type) { + case XS_TRANSACTION_START: + case XS_TRANSACTION_END: + case XS_DIRECTORY: + case XS_READ: + case XS_GET_PERMS: + case XS_RELEASE: + case XS_GET_DOMAIN_PATH: + case XS_WRITE: + case XS_MKDIR: + case XS_RM: + case XS_SET_PERMS: + error = xs_dev_request_and_reply(&u->u.msg, &reply); + if (!error) { + if (u->u.msg.type == XS_TRANSACTION_START) { + trans = malloc(sizeof(*trans), M_XENSTORE, + M_WAITOK); + trans->handle.id = strtoul(reply, NULL, 0); + LIST_INSERT_HEAD(&u->transactions, trans, list); + } else if (u->u.msg.type == XS_TRANSACTION_END) { + LIST_FOREACH(trans, &u->transactions, list) + if (trans->handle.id == u->u.msg.tx_id) + break; +#if 0 /* XXX does this mean the list is empty? */ + BUG_ON(&trans->list == &u->transactions); +#endif + LIST_REMOVE(trans, list); + free(trans, M_XENSTORE); + } + xs_queue_reply(u, (char *)&u->u.msg, sizeof(u->u.msg)); + xs_queue_reply(u, (char *)reply, u->u.msg.len); + free(reply, M_XENSTORE); + } + break; + + default: + error = EINVAL; + break; + } + + if (error == 0) + u->len = 0; + + return (error); +} + +static int +xs_dev_open(struct cdev *dev, int oflags, int devtype, struct thread *td) +{ + struct xs_dev_data *u; + +#if 0 /* XXX figure out if equiv needed */ + nonseekable_open(inode, filp); +#endif + u = malloc(sizeof(*u), M_XENSTORE, M_WAITOK|M_ZERO); + LIST_INIT(&u->transactions); + dev->si_drv1 = u; + + return (0); +} + +static int +xs_dev_close(struct cdev *dev, int fflag, int devtype, struct thread *td) +{ + struct xs_dev_data *u = dev->si_drv1; + struct xs_dev_transaction *trans, *tmp; + + LIST_FOREACH_SAFE(trans, &u->transactions, list, tmp) { + xs_transaction_end(trans->handle, 1); + LIST_REMOVE(trans, list); + free(trans, M_XENSTORE); + } + + free(u, M_XENSTORE); + return (0); +} + +static struct cdevsw xs_dev_cdevsw = { + .d_version = D_VERSION, + .d_read = xs_dev_read, + .d_write = xs_dev_write, + .d_open = xs_dev_open, + .d_close = xs_dev_close, + .d_name = "xs_dev", +}; + +void +xs_dev_init() +{ + make_dev(&xs_dev_cdevsw, 0, UID_ROOT, GID_WHEEL, 0400, + "xen/xenstore"); +} |
