/* * 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; }