/* * 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 <linux/kernel.h> #include <linux/uaccess.h> #include <linux/slab.h> #include <linux/sched.h> #include <linux/stddef.h> #include <linux/types.h> #include <linux/uio.h> #include <net/9p/9p.h> #include <net/9p/client.h> #include "protocol.h" #include <trace/events/9p.h> static int p9pdu_writef(struct p9_fcall *pdu, int proto_version, 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); 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; } static size_t pdu_write_u(struct p9_fcall *pdu, struct iov_iter *from, size_t size) { size_t len = min(pdu->capacity - pdu->size, size); struct iov_iter i = *from; if (copy_from_iter(&pdu->sdata[pdu->size], len, &i) != len) len = 0; pdu->size += len; return size - len; } /* b - int8_t w - int16_t d - int32_t q - int64_t s - string u - numeric uid g - numeric gid 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) A - stat for 9p2000.L (p9_stat_dotl) ? - if optional = 1, continue parsing */ static int p9pdu_vreadf(struct p9_fcall *pdu, int proto_version, 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 *); __le16 le_val; if (pdu_read(pdu, &le_val, sizeof(le_val))) { errcode = -EFAULT; break; } *val = le16_to_cpu(le_val); } break; case 'd':{ int32_t *val = va_arg(ap, int32_t *); __le32 le_val; if (pdu_read(pdu, &le_val, sizeof(le_val))) { errcode = -EFAULT; break; } *val = le32_to_cpu(le_val); } break; case 'q':{ int64_t *val = va_arg(ap, int64_t *); __le64 le_val; if (pdu_read(pdu, &le_val, sizeof(le_val))) { errcode = -EFAULT; break; } *val = le64_to_cpu(le_val); } break; case 's':{ char **sptr = va_arg(ap, char **); uint16_t len; errcode = p9pdu_readf(pdu, proto_version, "w", &len); if (errcode) break; *sptr = kmalloc(len + 1, GFP_NOFS); if (*sptr == NULL) { errcode = -EFAULT; break; } if (pdu_read(pdu, *sptr, len)) { errcode = -EFAULT; kfree(*sptr); *sptr = NULL; } else (*sptr)[len] = 0; } break; case 'u': { kuid_t *uid = va_arg(ap, kuid_t *); __le32 le_val; if (pdu_read(pdu, &le_val, sizeof(le_val))) { errcode = -EFAULT; break; } *uid = make_kuid(&init_user_ns, le32_to_cpu(le_val)); } break; case 'g': { kgid_t *gid = va_arg(ap, kgid_t *); __le32 le_val; if (pdu_read(pdu, &le_val, sizeof(le_val))) { errcode = -EFAULT; break; } *gid = make_kgid(&init_user_ns, le32_to_cpu(le_val)); } break; case 'Q':{ struct p9_qid *qid = va_arg(ap, struct p9_qid *); errcode = p9pdu_readf(pdu, proto_version, "bdq", &qid->type, &qid->version, &qid->path); } break; case 'S':{ struct p9_wstat *stbuf = va_arg(ap, struct p9_wstat *); memset(stbuf, 0, sizeof(struct p9_wstat)); stbuf->n_uid = stbuf->n_muid = INVALID_UID; stbuf->n_gid = INVALID_GID; errcode = p9pdu_readf(pdu, proto_version, "wwdQdddqssss?sugu", &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':{ uint32_t *count = va_arg(ap, uint32_t *); void **data = va_arg(ap, void **); errcode = p9pdu_readf(pdu, proto_version, "d", count); if (!errcode) { *count = min_t(uint32_t, *count, pdu->size - pdu->offset); *data = &pdu->sdata[pdu->offset]; } } break; case 'T':{ uint16_t *nwname = va_arg(ap, uint16_t *); char ***wnames = va_arg(ap, char ***); errcode = p9pdu_readf(pdu, proto_version, "w", nwname); if (!errcode) { *wnames = kmalloc(sizeof(char *) * *nwname, GFP_NOFS); if (!*wnames) errcode = -ENOMEM; } if (!errcode) { int i; for (i = 0; i < *nwname; i++) { errcode = p9pdu_readf(pdu, proto_version, "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':{ uint16_t *nwqid = va_arg(ap, uint16_t *); struct p9_qid **wqids = va_arg(ap, struct p9_qid **); *wqids = NULL; errcode = p9pdu_readf(pdu, proto_version, "w", nwqid); if (!errcode) { *wqids = kmalloc(*nwqid * sizeof(struct p9_qid), GFP_NOFS); if (*wqids == NULL) errcode = -ENOMEM; } if (!errcode) { int i; for (i = 0; i < *nwqid; i++) { errcode = p9pdu_readf(pdu, proto_version, "Q", &(*wqids)[i]); if (errcode) break; } } if (errcode) { kfree(*wqids); *wqids = NULL; } } break; case 'A': { struct p9_stat_dotl *stbuf = va_arg(ap, struct p9_stat_dotl *); memset(stbuf, 0, sizeof(struct p9_stat_dotl)); errcode = p9pdu_readf(pdu, proto_version, "qQdugqqqqqqqqqqqqqqq", &stbuf->st_result_mask, &stbuf->qid, &stbuf->st_mode, &stbuf->st_uid, &stbuf->st_gid, &stbuf->st_nlink, &stbuf->st_rdev, &stbuf->st_size, &stbuf->st_blksize, &stbuf->st_blocks, &stbuf->st_atime_sec, &stbuf->st_atime_nsec, &stbuf->st_mtime_sec, &stbuf->st_mtime_nsec, &stbuf->st_ctime_sec, &stbuf->st_ctime_nsec, &stbuf->st_btime_sec, &stbuf->st_btime_nsec, &stbuf->st_gen, &stbuf->st_data_version); } break; case '?': if ((proto_version != p9_proto_2000u) && (proto_version != p9_proto_2000L)) return 0; break; default: BUG(); break; } if (errcode) break; } return errcode; } int p9pdu_vwritef(struct p9_fcall *pdu, int proto_version, 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':{ __le16 val = cpu_to_le16(va_arg(ap, int)); if (pdu_write(pdu, &val, sizeof(val))) errcode = -EFAULT; } break; case 'd':{ __le32 val = cpu_to_le32(va_arg(ap, int32_t)); if (pdu_write(pdu, &val, sizeof(val))) errcode = -EFAULT; } break; case 'q':{ __le64 val = cpu_to_le64(va_arg(ap, int64_t)); if (pdu_write(pdu, &val, sizeof(val))) errcode = -EFAULT; } break; case 's':{ const char *sptr = va_arg(ap, const char *); uint16_t len = 0; if (sptr) len = min_t(size_t, strlen(sptr), USHRT_MAX); errcode = p9pdu_writef(pdu, proto_version, "w", len); if (!errcode && pdu_write(pdu, sptr, len)) errcode = -EFAULT; } break; case 'u': { kuid_t uid = va_arg(ap, kuid_t); __le32 val = cpu_to_le32( from_kuid(&init_user_ns, uid)); if (pdu_write(pdu, &val, sizeof(val))) errcode = -EFAULT; } break; case 'g': { kgid_t gid = va_arg(ap, kgid_t); __le32 val = cpu_to_le32( from_kgid(&init_user_ns, gid)); if (pdu_write(pdu, &val, sizeof(val))) errcode = -EFAULT; } break; case 'Q':{ const struct p9_qid *qid = va_arg(ap, const struct p9_qid *); errcode = p9pdu_writef(pdu, proto_version, "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, proto_version, "wwdQdddqssss?sugu", 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 'V':{ uint32_t count = va_arg(ap, uint32_t); struct iov_iter *from = va_arg(ap, struct iov_iter *); errcode = p9pdu_writef(pdu, proto_version, "d", count); if (!errcode && pdu_write_u(pdu, from, count)) errcode = -EFAULT; } break; case 'T':{ uint16_t nwname = va_arg(ap, int); const char **wnames = va_arg(ap, const char **); errcode = p9pdu_writef(pdu, proto_version, "w", nwname); if (!errcode) { int i; for (i = 0; i < nwname; i++) { errcode = p9pdu_writef(pdu, proto_version, "s", wnames[i]); if (errcode) break; } } } break; case 'R':{ uint16_t nwqid = va_arg(ap, int); struct p9_qid *wqids = va_arg(ap, struct p9_qid *); errcode = p9pdu_writef(pdu, proto_version, "w", nwqid); if (!errcode) { int i; for (i = 0; i < nwqid; i++) { errcode = p9pdu_writef(pdu, proto_version, "Q", &wqids[i]); if (errcode) break; } } } break; case 'I':{ struct p9_iattr_dotl *p9attr = va_arg(ap, struct p9_iattr_dotl *); errcode = p9pdu_writef(pdu, proto_version, "ddugqqqqq", p9attr->valid, p9attr->mode, p9attr->uid, p9attr->gid, p9attr->size, p9attr->atime_sec, p9attr->atime_nsec, p9attr->mtime_sec, p9attr->mtime_nsec); } break; case '?': if ((proto_version != p9_proto_2000u) && (proto_version != p9_proto_2000L)) return 0; break; default: BUG(); break; } if (errcode) break; } return errcode; } int p9pdu_readf(struct p9_fcall *pdu, int proto_version, const char *fmt, ...) { va_list ap; int ret; va_start(ap, fmt); ret = p9pdu_vreadf(pdu, proto_version, fmt, ap); va_end(ap); return ret; } static int p9pdu_writef(struct p9_fcall *pdu, int proto_version, const char *fmt, ...) { va_list ap; int ret; va_start(ap, fmt); ret = p9pdu_vwritef(pdu, proto_version, fmt, ap); va_end(ap); return ret; } int p9stat_read(struct p9_client *clnt, char *buf, int len, struct p9_wstat *st) { struct p9_fcall fake_pdu; int ret; fake_pdu.size = len; fake_pdu.capacity = len; fake_pdu.sdata = buf; fake_pdu.offset = 0; ret = p9pdu_readf(&fake_pdu, clnt->proto_version, "S", st); if (ret) { p9_debug(P9_DEBUG_9P, "<<< p9stat_read failed: %d\n", ret); trace_9p_protocol_dump(clnt, &fake_pdu); } return ret; } EXPORT_SYMBOL(p9stat_read); int p9pdu_prepare(struct p9_fcall *pdu, int16_t tag, int8_t type) { pdu->id = type; return p9pdu_writef(pdu, 0, "dbw", 0, type, tag); } int p9pdu_finalize(struct p9_client *clnt, struct p9_fcall *pdu) { int size = pdu->size; int err; pdu->size = 0; err = p9pdu_writef(pdu, 0, "d", size); pdu->size = size; trace_9p_protocol_dump(clnt, pdu); p9_debug(P9_DEBUG_9P, ">>> size=%d type: %d tag: %d\n", pdu->size, pdu->id, pdu->tag); return err; } void p9pdu_reset(struct p9_fcall *pdu) { pdu->offset = 0; pdu->size = 0; } int p9dirent_read(struct p9_client *clnt, char *buf, int len, struct p9_dirent *dirent) { struct p9_fcall fake_pdu; int ret; char *nameptr; fake_pdu.size = len; fake_pdu.capacity = len; fake_pdu.sdata = buf; fake_pdu.offset = 0; ret = p9pdu_readf(&fake_pdu, clnt->proto_version, "Qqbs", &dirent->qid, &dirent->d_off, &dirent->d_type, &nameptr); if (ret) { p9_debug(P9_DEBUG_9P, "<<< p9dirent_read failed: %d\n", ret); trace_9p_protocol_dump(clnt, &fake_pdu); goto out; } strcpy(dirent->d_name, nameptr); kfree(nameptr); out: return fake_pdu.offset; } EXPORT_SYMBOL(p9dirent_read);