diff options
Diffstat (limited to 'net/9p/protocol.c')
-rw-r--r-- | net/9p/protocol.c | 457 |
1 files changed, 457 insertions, 0 deletions
diff --git a/net/9p/protocol.c b/net/9p/protocol.c new file mode 100644 index 0000000..43e9822 --- /dev/null +++ b/net/9p/protocol.c @@ -0,0 +1,457 @@ +/* + * net/9p/protocol.c + * + * 9P Protocol Support Code + * + * Copyright (C) 2008 by Eric Van Hensbergen <ericvh@gmail.com> + * + * Base on code from Anthony Liguori <aliguori@us.ibm.com> + * Copyright (C) 2008 by IBM, Corp. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 + * as published by the Free Software Foundation. + * + * 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, write to: + * Free Software Foundation + * 51 Franklin Street, Fifth Floor + * Boston, MA 02111-1301 USA + * + */ + +#include <linux/module.h> +#include <linux/errno.h> +#include <net/9p/9p.h> +#include <net/9p/client.h> +#include "protocol.h" + +#ifndef MIN +#define MIN(a, b) (((a) < (b)) ? (a) : (b)) +#endif + +#ifndef MAX +#define MAX(a, b) (((a) > (b)) ? (a) : (b)) +#endif + +#ifndef offset_of +#define offset_of(type, memb) \ + ((unsigned long)(&((type *)0)->memb)) +#endif +#ifndef container_of +#define container_of(obj, type, memb) \ + ((type *)(((char *)obj) - offset_of(type, memb))) +#endif + +static int +p9pdu_writef(struct p9_fcall *pdu, int optional, const char *fmt, ...); + +void p9stat_free(struct p9_wstat *stbuf) +{ + kfree(stbuf->name); + kfree(stbuf->uid); + kfree(stbuf->gid); + kfree(stbuf->muid); + kfree(stbuf->extension); +} +EXPORT_SYMBOL(p9stat_free); + +static size_t pdu_read(struct p9_fcall *pdu, void *data, size_t size) +{ + size_t len = MIN(pdu->size - pdu->offset, size); + memcpy(data, &pdu->sdata[pdu->offset], len); + pdu->offset += len; + return size - len; +} + +static size_t pdu_write(struct p9_fcall *pdu, const void *data, size_t size) +{ + size_t len = MIN(pdu->capacity - pdu->size, size); + memcpy(&pdu->sdata[pdu->size], data, len); + pdu->size += len; + return size - len; +} + +/* + b - int8_t + w - int16_t + d - int32_t + q - int64_t + s - string + S - stat + Q - qid + D - data blob (int32_t size followed by void *, results are not freed) + T - array of strings (int16_t count, followed by strings) + R - array of qids (int16_t count, followed by qids) + ? - if optional = 1, continue parsing +*/ + +static int +p9pdu_vreadf(struct p9_fcall *pdu, int optional, const char *fmt, va_list ap) +{ + const char *ptr; + int errcode = 0; + + for (ptr = fmt; *ptr; ptr++) { + switch (*ptr) { + case 'b':{ + int8_t *val = va_arg(ap, int8_t *); + if (pdu_read(pdu, val, sizeof(*val))) { + errcode = -EFAULT; + break; + } + } + break; + case 'w':{ + int16_t *val = va_arg(ap, int16_t *); + if (pdu_read(pdu, val, sizeof(*val))) { + errcode = -EFAULT; + break; + } + *val = cpu_to_le16(*val); + } + break; + case 'd':{ + int32_t *val = va_arg(ap, int32_t *); + if (pdu_read(pdu, val, sizeof(*val))) { + errcode = -EFAULT; + break; + } + *val = cpu_to_le32(*val); + } + break; + case 'q':{ + int64_t *val = va_arg(ap, int64_t *); + if (pdu_read(pdu, val, sizeof(*val))) { + errcode = -EFAULT; + break; + } + *val = cpu_to_le64(*val); + } + break; + case 's':{ + char **ptr = va_arg(ap, char **); + int16_t len; + int size; + + errcode = p9pdu_readf(pdu, optional, "w", &len); + if (errcode) + break; + + size = MAX(len, 0); + + *ptr = kmalloc(size + 1, GFP_KERNEL); + if (*ptr == NULL) { + errcode = -EFAULT; + break; + } + if (pdu_read(pdu, *ptr, size)) { + errcode = -EFAULT; + kfree(*ptr); + *ptr = NULL; + } else + (*ptr)[size] = 0; + } + break; + case 'Q':{ + struct p9_qid *qid = + va_arg(ap, struct p9_qid *); + + errcode = p9pdu_readf(pdu, optional, "bdq", + &qid->type, &qid->version, + &qid->path); + } + break; + case 'S':{ + struct p9_wstat *stbuf = + va_arg(ap, struct p9_wstat *); + + stbuf->extension = NULL; + stbuf->n_uid = stbuf->n_gid = stbuf->n_muid = + -1; + + errcode = + p9pdu_readf(pdu, optional, + "wwdQdddqssss?sddd", + &stbuf->size, &stbuf->type, + &stbuf->dev, &stbuf->qid, + &stbuf->mode, &stbuf->atime, + &stbuf->mtime, &stbuf->length, + &stbuf->name, &stbuf->uid, + &stbuf->gid, &stbuf->muid, + &stbuf->extension, + &stbuf->n_uid, &stbuf->n_gid, + &stbuf->n_muid); + if (errcode) + p9stat_free(stbuf); + } + break; + case 'D':{ + int32_t *count = va_arg(ap, int32_t *); + void **data = va_arg(ap, void **); + + errcode = + p9pdu_readf(pdu, optional, "d", count); + if (!errcode) { + *count = + MIN(*count, + pdu->size - pdu->offset); + *data = &pdu->sdata[pdu->offset]; + } + } + break; + case 'T':{ + int16_t *nwname = va_arg(ap, int16_t *); + char ***wnames = va_arg(ap, char ***); + + errcode = + p9pdu_readf(pdu, optional, "w", nwname); + if (!errcode) { + *wnames = + kmalloc(sizeof(char *) * *nwname, + GFP_KERNEL); + if (!*wnames) + errcode = -ENOMEM; + } + + if (!errcode) { + int i; + + for (i = 0; i < *nwname; i++) { + errcode = + p9pdu_readf(pdu, optional, + "s", + &(*wnames)[i]); + if (errcode) + break; + } + } + + if (errcode) { + if (*wnames) { + int i; + + for (i = 0; i < *nwname; i++) + kfree((*wnames)[i]); + } + kfree(*wnames); + *wnames = NULL; + } + } + break; + case 'R':{ + int16_t *nwqid = va_arg(ap, int16_t *); + struct p9_qid **wqids = + va_arg(ap, struct p9_qid **); + + *wqids = NULL; + + errcode = + p9pdu_readf(pdu, optional, "w", nwqid); + if (!errcode) { + *wqids = + kmalloc(*nwqid * + sizeof(struct p9_qid), + GFP_KERNEL); + if (*wqids == NULL) + errcode = -ENOMEM; + } + + if (!errcode) { + int i; + + for (i = 0; i < *nwqid; i++) { + errcode = + p9pdu_readf(pdu, optional, + "Q", + &(*wqids)[i]); + if (errcode) + break; + } + } + + if (errcode) { + kfree(*wqids); + *wqids = NULL; + } + } + break; + case '?': + if (!optional) + return 0; + break; + default: + BUG(); + break; + } + + if (errcode) + break; + } + + return errcode; +} + +int +p9pdu_vwritef(struct p9_fcall *pdu, int optional, const char *fmt, va_list ap) +{ + const char *ptr; + int errcode = 0; + + for (ptr = fmt; *ptr; ptr++) { + switch (*ptr) { + case 'b':{ + int8_t val = va_arg(ap, int); + if (pdu_write(pdu, &val, sizeof(val))) + errcode = -EFAULT; + } + break; + case 'w':{ + int16_t val = va_arg(ap, int); + if (pdu_write(pdu, &val, sizeof(val))) + errcode = -EFAULT; + } + break; + case 'd':{ + int32_t val = va_arg(ap, int32_t); + if (pdu_write(pdu, &val, sizeof(val))) + errcode = -EFAULT; + } + break; + case 'q':{ + int64_t val = va_arg(ap, int64_t); + if (pdu_write(pdu, &val, sizeof(val))) + errcode = -EFAULT; + } + break; + case 's':{ + const char *ptr = va_arg(ap, const char *); + int16_t len = 0; + + if (ptr) + len = MIN(strlen(ptr), USHORT_MAX); + + errcode = p9pdu_writef(pdu, optional, "w", len); + if (!errcode && pdu_write(pdu, ptr, len)) + errcode = -EFAULT; + } + break; + case 'Q':{ + const struct p9_qid *qid = + va_arg(ap, const struct p9_qid *); + errcode = + p9pdu_writef(pdu, optional, "bdq", + qid->type, qid->version, + qid->path); + } break; + case 'S':{ + const struct p9_wstat *stbuf = + va_arg(ap, const struct p9_wstat *); + errcode = + p9pdu_writef(pdu, optional, + "wwdQdddqssss?sddd", + stbuf->size, stbuf->type, + stbuf->dev, stbuf->qid, + stbuf->mode, stbuf->atime, + stbuf->mtime, stbuf->length, + stbuf->name, stbuf->uid, + stbuf->gid, stbuf->muid, + stbuf->extension, stbuf->n_uid, + stbuf->n_gid, stbuf->n_muid); + } break; + case 'D':{ + int32_t count = va_arg(ap, int32_t); + const void *data = va_arg(ap, const void *); + + errcode = + p9pdu_writef(pdu, optional, "d", count); + if (!errcode && pdu_write(pdu, data, count)) + errcode = -EFAULT; + } + break; + case 'T':{ + int16_t nwname = va_arg(ap, int); + const char **wnames = va_arg(ap, const char **); + + errcode = + p9pdu_writef(pdu, optional, "w", nwname); + if (!errcode) { + int i; + + for (i = 0; i < nwname; i++) { + errcode = + p9pdu_writef(pdu, optional, + "s", + wnames[i]); + if (errcode) + break; + } + } + } + break; + case 'R':{ + int16_t nwqid = va_arg(ap, int); + struct p9_qid *wqids = + va_arg(ap, struct p9_qid *); + + errcode = + p9pdu_writef(pdu, optional, "w", nwqid); + if (!errcode) { + int i; + + for (i = 0; i < nwqid; i++) { + errcode = + p9pdu_writef(pdu, optional, + "Q", + &wqids[i]); + if (errcode) + break; + } + } + } + break; + case '?': + if (!optional) + return 0; + break; + default: + BUG(); + break; + } + + if (errcode) + break; + } + + return errcode; +} + +int p9pdu_readf(struct p9_fcall *pdu, int optional, const char *fmt, ...) +{ + va_list ap; + int ret; + + va_start(ap, fmt); + ret = p9pdu_vreadf(pdu, optional, fmt, ap); + va_end(ap); + + return ret; +} + +static int +p9pdu_writef(struct p9_fcall *pdu, int optional, const char *fmt, ...) +{ + va_list ap; + int ret; + + va_start(ap, fmt); + ret = p9pdu_vwritef(pdu, optional, fmt, ap); + va_end(ap); + + return ret; +} |