/**************************************************************************** * fs/romfs/fs_romfsutil.c * * Licensed to the Apache Software Foundation (ASF) under one or more * contributor license agreements. See the NOTICE file distributed with * this work for additional information regarding copyright ownership. The * ASF licenses this file to you under the Apache License, Version 2.0 (the * "License"); you may not use this file except in compliance with the * License. You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the * License for the specific language governing permissions and limitations * under the License. * ****************************************************************************/ /* References: Linux/Documentation/filesystems/romfs.txt */ /**************************************************************************** * Included Files ****************************************************************************/ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include "fs_romfs.h" /**************************************************************************** * Pre-processor Definitions ****************************************************************************/ #define LINK_NOT_FOLLOWED 0 #define LINK_FOLLOWED 1 /**************************************************************************** * Private Functions ****************************************************************************/ /**************************************************************************** * Name: romfs_devread32 * * Description: * Read the big-endian 32-bit value from the mount device buffer * * Assumption: * All values are aligned to 32-bit boundaries * ****************************************************************************/ static uint32_t romfs_devread32(struct romfs_mountpt_s *rm, int ndx) { /* This should not read past the end of the sector since the directory * entries are aligned at 16-byte boundaries. */ return ((((uint32_t)rm->rm_buffer[ndx] & 0xff) << 24) | (((uint32_t)rm->rm_buffer[ndx + 1] & 0xff) << 16) | (((uint32_t)rm->rm_buffer[ndx + 2] & 0xff) << 8) | ((uint32_t)rm->rm_buffer[ndx + 3] & 0xff)); } /**************************************************************************** * Name: romfs_checkentry * * Description: * Check if the entry at offset is a directory or file path segment * ****************************************************************************/ static inline int romfs_checkentry(struct romfs_mountpt_s *rm, uint32_t offset, const char *entryname, int entrylen, struct romfs_dirinfo_s *dirinfo) { char name[NAME_MAX + 1]; uint32_t linkoffset; uint32_t next; uint32_t info; uint32_t size; int ret; /* Parse the directory entry at this offset (which may be re-directed * to some other entry if HARLINKED). */ ret = romfs_parsedirentry(rm, offset, &linkoffset, &next, &info, &size); if (ret < 0) { return ret; } /* Now we are pointing to the real entry of interest. Is it a * directory? Or a file? */ if (IS_DIRECTORY(next) || IS_FILE(next)) { /* Get the name of the directory entry. */ ret = romfs_parsefilename(rm, offset, name); if (ret < 0) { return ret; } /* Then check if this the name segment we are looking for. The * string comparison is awkward because there is no terminator * on entryname (there is a terminator on name, however) */ if (memcmp(entryname, name, entrylen) == 0 && strlen(name) == entrylen) { /* Found it -- save the component info and return success */ if (IS_DIRECTORY(next)) { dirinfo->rd_dir.fr_firstoffset = info; dirinfo->rd_dir.fr_curroffset = info; dirinfo->rd_size = 0; } else { dirinfo->rd_dir.fr_curroffset = offset; dirinfo->rd_size = size; } dirinfo->rd_next = next; return OK; } } /* The entry is not a directory or it does not have the matching name */ return -ENOENT; } /**************************************************************************** * Name: romfs_devcacheread * * Description: * Read the specified sector for specified offset into the sector cache. * Return the index into the sector corresponding to the offset * ****************************************************************************/ int16_t romfs_devcacheread(struct romfs_mountpt_s *rm, uint32_t offset) { uint32_t sector; int ret; /* rm->rm_cachesector holds the current sector that is buffer in or * referenced by rm->tm_buffer. If the requested sector is the same as this * this then we do nothing. */ sector = SEC_NSECTORS(rm, offset); if (rm->rm_cachesector != sector) { /* Check the access mode */ if (rm->rm_xipbase) { /* In XIP mode, rf_buffer is just an offset pointer into the device * address space. */ rm->rm_buffer = rm->rm_xipbase + SEC_ALIGN(rm, offset); } else { /* In non-XIP mode, we will have to read the new sector. */ ret = romfs_hwread(rm, rm->rm_buffer, sector, 1); if (ret < 0) { return (int16_t)ret; } } /* Update the cached sector number */ rm->rm_cachesector = sector; } /* Return the offset */ return offset & SEC_NDXMASK(rm); } /**************************************************************************** * Name: romfs_followhardlinks * * Description: * Given the offset to a file header, check if the file is a hardlink. * If so, traverse the hard links until the terminal, non-linked header * so found and return that offset. * * Return value: * < 0 : An error occurred * 0 : No link followed * 1 : Link followed, poffset is the new volume offset * ****************************************************************************/ static int romfs_followhardlinks(struct romfs_mountpt_s *rm, uint32_t offset, uint32_t *poffset) { uint32_t next; int16_t ndx; int i; int ret = LINK_NOT_FOLLOWED; /* Loop while we are redirected by hardlinks */ for (i = 0; i < ROMF_MAX_LINKS; i++) { /* Read the sector containing the offset into memory */ ndx = romfs_devcacheread(rm, offset); if (ndx < 0) { return ndx; } /* Check if this is a hard link */ next = romfs_devread32(rm, ndx + ROMFS_FHDR_NEXT); if (!IS_HARDLINK(next)) { *poffset = offset; return ret; } /* Follow the hard-link. Set return to indicate that we followed a * link and that poffset was set to the link offset is valid. */ offset = romfs_devread32(rm, ndx + ROMFS_FHDR_INFO); ret = LINK_FOLLOWED; } return -ELOOP; } /**************************************************************************** * Name: romfs_searchdir * * Description: * This is part of the romfs_finddirentry log. Search the directory * beginning at dirinfo->fr_firstoffset for entryname. * ****************************************************************************/ static inline int romfs_searchdir(struct romfs_mountpt_s *rm, const char *entryname, int entrylen, struct romfs_dirinfo_s *dirinfo) { uint32_t offset; uint32_t next; int16_t ndx; int ret; /* Then loop through the current directory until the directory * with the matching name is found. Or until all of the entries * the directory have been examined. */ offset = dirinfo->rd_dir.fr_firstoffset; do { /* Read the sector into memory (do this before calling * romfs_checkentry() so we won't have to read the sector * twice in the event that the offset refers to a hardlink). */ ndx = romfs_devcacheread(rm, offset); if (ndx < 0) { return ndx; } /* Because everything is chunked and aligned to 16-bit boundaries, * we know that most the basic node info fits into the sector. */ next = romfs_devread32(rm, ndx + ROMFS_FHDR_NEXT) & RFNEXT_OFFSETMASK; /* Check if the name this entry is a directory with the matching * name */ ret = romfs_checkentry(rm, offset, entryname, entrylen, dirinfo); if (ret == OK) { /* Its a match! Return success */ return OK; } /* No match... select the offset to the next entry */ offset = next; } while (next != 0); /* There is nothing in this directory with that name */ return -ENOENT; } /**************************************************************************** * Public Functions ****************************************************************************/ /**************************************************************************** * Name: romfs_semtake ****************************************************************************/ int romfs_semtake(struct romfs_mountpt_s *rm) { return nxsem_wait_uninterruptible(&rm->rm_sem); } /**************************************************************************** * Name: romfs_semgive ****************************************************************************/ void romfs_semgive(struct romfs_mountpt_s *rm) { nxsem_post(&rm->rm_sem); } /**************************************************************************** * Name: romfs_hwread * * Description: Read the specified sector into the sector buffer * ****************************************************************************/ int romfs_hwread(struct romfs_mountpt_s *rm, uint8_t *buffer, uint32_t sector, unsigned int nsectors) { int ret = OK; /* Check the access mode */ if (rm->rm_xipbase) { /* In XIP mode, we just copy the requested data */ memcpy(buffer, rm->rm_xipbase + sector*rm->rm_hwsectorsize, nsectors*rm->rm_hwsectorsize); } else { /* In non-XIP mode, we have to read the data from the device */ struct inode *inode = rm->rm_blkdriver; ssize_t nsectorsread = -ENODEV; DEBUGASSERT(inode); if (INODE_IS_MTD(inode)) { nsectorsread = MTD_BREAD(inode->u.i_mtd, sector, nsectors, buffer); } else if (inode->u.i_bops->read) { nsectorsread = inode->u.i_bops->read(inode, buffer, sector, nsectors); } if (nsectorsread == (ssize_t)nsectors) { ret = OK; } else if (nsectorsread < 0) { ret = nsectorsread; } } return ret; } /**************************************************************************** * Name: romfs_filecacheread * * Description: * Read the specified sector into the sector cache * ****************************************************************************/ int romfs_filecacheread(struct romfs_mountpt_s *rm, struct romfs_file_s *rf, uint32_t sector) { int ret; finfo("sector: %" PRId32 " cached: %" PRId32 " sectorsize: %d XIP base: %p buffer: %p\n", sector, rf->rf_cachesector, rm->rm_hwsectorsize, rm->rm_xipbase, rf->rf_buffer); /* rf->rf_cachesector holds the current sector that is buffer in or * referenced by rf->rf_buffer. If the requested sector is the same as this * sector then we do nothing. */ if (rf->rf_cachesector != sector) { /* Check the access mode */ if (rm->rm_xipbase) { /* In XIP mode, rf_buffer is just an offset pointer into the device * address space. */ rf->rf_buffer = rm->rm_xipbase + sector * rm->rm_hwsectorsize; finfo("XIP buffer: %p\n", rf->rf_buffer); } else { /* In non-XIP mode, we will have to read the new sector. */ finfo("Calling romfs_hwread\n"); ret = romfs_hwread(rm, rf->rf_buffer, sector, 1); if (ret < 0) { ferr("ERROR: romfs_hwread failed: %d\n", ret); return ret; } } /* Update the cached sector number */ rf->rf_cachesector = sector; } return OK; } /**************************************************************************** * Name: romfs_hwconfigure * * Description: * This function is called as part of the ROMFS mount operation. * It configures the ROMFS filestem for use on this block driver. This * include the accounting for the geometry of the device, setting up any * XIP modes of operation, and/or allocating any cache buffers. * ****************************************************************************/ int romfs_hwconfigure(struct romfs_mountpt_s *rm) { struct inode *inode = rm->rm_blkdriver; int ret; /* Get the underlying device geometry */ #ifdef CONFIG_DEBUG_FEATURES if (inode == NULL) { return -ENODEV; } #endif if (INODE_IS_MTD(inode)) { struct mtd_geometry_s mgeo; ret = MTD_IOCTL(inode->u.i_mtd, MTDIOC_GEOMETRY, (unsigned long)&mgeo); if (ret != OK) { return ret; } /* Save that information in the mount structure */ rm->rm_hwsectorsize = mgeo.blocksize; rm->rm_hwnsectors = mgeo.neraseblocks * (mgeo.erasesize / mgeo.blocksize); } else { struct geometry geo; ret = inode->u.i_bops->geometry(inode, &geo); if (ret != OK) { return ret; } if (!geo.geo_available) { return -EBUSY; } /* Save that information in the mount structure */ rm->rm_hwsectorsize = geo.geo_sectorsize; rm->rm_hwnsectors = geo.geo_nsectors; } /* Determine if block driver supports the XIP mode of operation */ rm->rm_cachesector = (uint32_t)-1; if (INODE_IS_MTD(inode)) { ret = MTD_IOCTL(inode->u.i_mtd, BIOC_XIPBASE, (unsigned long)&rm->rm_xipbase); } else if (inode->u.i_bops->ioctl != NULL) { ret = inode->u.i_bops->ioctl(inode, BIOC_XIPBASE, (unsigned long)&rm->rm_xipbase); } else { ret = -ENOTSUP; } if (ret == OK && rm->rm_xipbase) { /* Yes.. Then we will directly access the media (vs. * copying into an allocated sector buffer. */ rm->rm_buffer = rm->rm_xipbase; rm->rm_cachesector = 0; return OK; } /* Allocate the device cache buffer for normal sector accesses */ rm->rm_buffer = (FAR uint8_t *)kmm_malloc(rm->rm_hwsectorsize); if (!rm->rm_buffer) { return -ENOMEM; } return OK; } /**************************************************************************** * Name: romfs_fsconfigure * * Description: * This function is called as part of the ROMFS mount operation It * sets up the mount structure to include configuration information * contained in the ROMFS header. This is the place where we actually * determine if the media contains a ROMFS filesystem. * ****************************************************************************/ int romfs_fsconfigure(struct romfs_mountpt_s *rm) { const char *name; int16_t ndx; /* Then get information about the ROMFS filesystem on the devices managed * by this block driver. Read sector zero which contains the volume header. */ ndx = romfs_devcacheread(rm, 0); if (ndx < 0) { return ndx; } /* Verify the magic number at that identifies this as a ROMFS filesystem */ if (memcmp(rm->rm_buffer, ROMFS_VHDR_MAGIC, 8) != 0) { return -EINVAL; } /* Then extract the values we need from the header and return success */ rm->rm_volsize = romfs_devread32(rm, ROMFS_VHDR_SIZE); /* The root directory entry begins right after the header */ name = (FAR const char *)&rm->rm_buffer[ROMFS_VHDR_VOLNAME]; rm->rm_rootoffset = ROMFS_ALIGNUP(ROMFS_VHDR_VOLNAME + strlen(name) + 1); /* and return success */ rm->rm_mounted = true; return OK; } /**************************************************************************** * Name: romfs_fileconfigure * * Description: * This function is called as part of the ROMFS file open operation It * sets up the file structure to handle buffer appropriately, depending * upon XIP mode or not. * ****************************************************************************/ int romfs_fileconfigure(struct romfs_mountpt_s *rm, struct romfs_file_s *rf) { /* Check if XIP access mode is supported. If so, then we do not need * to allocate anything. */ if (rm->rm_xipbase) { /* We'll put a valid address in rf_buffer just in case. */ rf->rf_cachesector = 0; rf->rf_buffer = rm->rm_xipbase; } else { /* Nothing in the cache buffer */ rf->rf_cachesector = (uint32_t)-1; /* Create a file buffer to support partial sector accesses */ rf->rf_buffer = (FAR uint8_t *)kmm_malloc(rm->rm_hwsectorsize); if (!rf->rf_buffer) { return -ENOMEM; } } return OK; } /**************************************************************************** * Name: romfs_checkmount * * Description: Check if the mountpoint is still valid. * * The caller should hold the mountpoint semaphore * ****************************************************************************/ int romfs_checkmount(struct romfs_mountpt_s *rm) { struct inode *inode; struct geometry geo; int ret; /* If the fs_mounted flag is false, then we have already handled the loss * of the mount. */ DEBUGASSERT(rm && rm->rm_blkdriver); if (rm->rm_mounted) { /* We still think the mount is healthy. Check an see if this is * still the case */ inode = rm->rm_blkdriver; if (INODE_IS_MTD(inode)) { /* It is impossible to remove MTD device */ return OK; } else if (inode->u.i_bops->geometry) { ret = inode->u.i_bops->geometry(inode, &geo); if (ret == OK && geo.geo_available && !geo.geo_mediachanged) { return OK; } } /* If we get here, the mount is NOT healthy */ rm->rm_mounted = false; } return -ENODEV; } /**************************************************************************** * Name: romfs_finddirentry * * Description: * Given a path to something that may or may not be in the file system, * return the directory entry of the item. * ****************************************************************************/ int romfs_finddirentry(struct romfs_mountpt_s *rm, struct romfs_dirinfo_s *dirinfo, const char *path) { const char *entryname; const char *terminator; int entrylen; int ret; /* Start with the first element after the root directory */ dirinfo->rd_dir.fr_firstoffset = rm->rm_rootoffset; dirinfo->rd_dir.fr_curroffset = rm->rm_rootoffset; dirinfo->rd_next = RFNEXT_DIRECTORY; dirinfo->rd_size = 0; /* The root directory is a special case */ if (!path || path[0] == '\0') { return OK; } /* Then loop for each directory/file component in the full path */ entryname = path; terminator = NULL; for (; ; ) { /* Find the start of the next path component */ while (*entryname == '/') entryname++; /* Find the end of the next path component */ terminator = strchr(entryname, '/'); if (!terminator) { entrylen = strlen(entryname); } else { entrylen = terminator - entryname; } if (entrylen == 0) { return OK; } /* Long path segment names will be truncated to NAME_MAX */ if (entrylen > NAME_MAX) { entrylen = NAME_MAX; } /* Then find the entry in the current directory with the * matching name. */ ret = romfs_searchdir(rm, entryname, entrylen, dirinfo); if (ret < 0) { return ret; } /* Was that the last path component? */ if (!terminator) { /* Yes.. return success */ return OK; } /* No... If that was not the last path component, then it had * better have been a directory */ if (!IS_DIRECTORY(dirinfo->rd_next)) { return -ENOTDIR; } /* Setup to search the next directory for the next component * of the path */ entryname = terminator; } return ERROR; /* Won't get here */ } /**************************************************************************** * Name: romfs_parsedirentry * * Description: * Return the directory entry at this offset. If rf is NULL, then the * mount device resources are used. Otherwise, file resources are used. * ****************************************************************************/ int romfs_parsedirentry(struct romfs_mountpt_s *rm, uint32_t offset, uint32_t *poffset, uint32_t *pnext, uint32_t *pinfo, uint32_t *psize) { uint32_t save; uint32_t next; int16_t ndx; int ret; /* Read the sector into memory */ ndx = romfs_devcacheread(rm, offset); if (ndx < 0) { return ndx; } /* Yes.. Save the first 'next' value. That has the offset needed to * traverse the parent directory. But we may need to change the type * after we follow the hard links. */ save = romfs_devread32(rm, ndx + ROMFS_FHDR_NEXT); /* Traverse hardlinks as necessary to get to the real file header */ ret = romfs_followhardlinks(rm, offset, poffset); if (ret < 0) { return ret; } else if (ret > 0) { /* The link was followed */ ndx = romfs_devcacheread(rm, *poffset); if (ndx < 0) { return ndx; } } /* Because everything is chunked and aligned to 16-bit boundaries, * we know that most the basic node info fits into the sector. The * associated name may not, however. * * NOTE: Since ROMFS directory entries are aligned to 16-byte boundaries, * we are assured that ndx + ROMFS_FHDR_INFO/SIZE will lie wholly within * the sector buffer. */ next = romfs_devread32(rm, ndx + ROMFS_FHDR_NEXT); *pnext = (save & RFNEXT_OFFSETMASK) | (next & RFNEXT_ALLMODEMASK); *pinfo = romfs_devread32(rm, ndx + ROMFS_FHDR_INFO); *psize = romfs_devread32(rm, ndx + ROMFS_FHDR_SIZE); return OK; } /**************************************************************************** * Name: romfs_parsefilename * * Description: * Return the filename from directory entry at this offset * ****************************************************************************/ int romfs_parsefilename(struct romfs_mountpt_s *rm, uint32_t offset, char *pname) { int16_t ndx; uint16_t namelen; uint16_t chunklen; bool done; /* Loop until the whole name is obtained or until NAME_MAX characters * of the name have been parsed. */ offset += ROMFS_FHDR_NAME; for (namelen = 0, done = false; namelen < NAME_MAX && !done; ) { /* Read the sector into memory */ ndx = romfs_devcacheread(rm, offset + namelen); if (ndx < 0) { return ndx; } /* Is the name terminated in this 16-byte block */ if (rm->rm_buffer[ndx + 15] == '\0') { /* Yes.. then this chunk is less than 16 */ chunklen = strlen((FAR char *)&rm->rm_buffer[ndx]); done = true; } else { /* No.. then this chunk is 16 bytes in length */ chunklen = 16; } /* Check if we would exceed the NAME_MAX */ if (namelen + chunklen > NAME_MAX) { chunklen = NAME_MAX - namelen; done = true; } /* Copy the chunk */ memcpy(&pname[namelen], &rm->rm_buffer[ndx], chunklen); namelen += chunklen; } /* Terminate the name (NAME_MAX+1 chars total) and return success */ pname[namelen] = '\0'; return OK; } /**************************************************************************** * Name: romfs_datastart * * Description: * Given the offset to a file header, return the offset to the start of * the file data * ****************************************************************************/ int romfs_datastart(struct romfs_mountpt_s *rm, uint32_t offset, uint32_t *start) { int16_t ndx; int ret; /* Traverse hardlinks as necessary to get to the real file header */ ret = romfs_followhardlinks(rm, offset, &offset); if (ret < 0) { return ret; } /* Loop until the header size is obtained. */ offset += ROMFS_FHDR_NAME; for (; ; ) { /* Read the sector into memory */ ndx = romfs_devcacheread(rm, offset); if (ndx < 0) { return ndx; } /* Get the offset to the next chunk */ offset += 16; if (offset > rm->rm_volsize) { return -EIO; } /* Is the name terminated in this 16-byte block */ if (rm->rm_buffer[ndx + 15] == '\0') { /* Yes.. then the data starts at the next chunk */ *start = offset; return OK; } } return -EINVAL; /* Won't get here */ }