/**************************************************************************** * fs/procfs/fs_procfstcbinfo.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. * ****************************************************************************/ /**************************************************************************** * Included Files ****************************************************************************/ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include "fs_heap.h" #if !defined(CONFIG_DISABLE_MOUNTPOINT) && defined(CONFIG_FS_PROCFS) && \ defined(CONFIG_ARCH_HAVE_TCBINFO) && !defined(CONFIG_FS_PROCFS_EXCLUDE_TCBINFO) /**************************************************************************** * Pre-processor Definitions ****************************************************************************/ /* Determines the size of an intermediate buffer that must be large enough * to handle the longest line generated by this logic. */ #define TCBINFO_LINELEN 128 /**************************************************************************** * Private Types ****************************************************************************/ /* This structure describes one open "file" */ struct tcbinfo_file_s { struct procfs_file_s base; /* Base open file structure */ unsigned int linesize; /* Number of valid characters in line[] */ char line[TCBINFO_LINELEN]; /* Pre-allocated buffer for formatted lines */ }; /**************************************************************************** * Private Function Prototypes ****************************************************************************/ /* File system methods */ static int tcbinfo_open(FAR struct file *filep, FAR const char *relpath, int oflags, mode_t mode); static int tcbinfo_close(FAR struct file *filep); static ssize_t tcbinfo_read(FAR struct file *filep, FAR char *buffer, size_t buflen); static int tcbinfo_dup(FAR const struct file *oldp, FAR struct file *newp); static int tcbinfo_stat(FAR const char *relpath, FAR struct stat *buf); /**************************************************************************** * Public Data ****************************************************************************/ /* See fs_mount.c -- this structure is explicitly externed there. * We use the old-fashioned kind of initializers so that this will compile * with any compiler. */ const struct procfs_operations g_tcbinfo_operations = { tcbinfo_open, /* open */ tcbinfo_close, /* close */ tcbinfo_read, /* read */ NULL, /* write */ NULL, /* poll */ tcbinfo_dup, /* dup */ NULL, /* opendir */ NULL, /* closedir */ NULL, /* readdir */ NULL, /* rewinddir */ tcbinfo_stat /* stat */ }; /**************************************************************************** * Private Functions ****************************************************************************/ /**************************************************************************** * Name: tcbinfo_open ****************************************************************************/ static int tcbinfo_open(FAR struct file *filep, FAR const char *relpath, int oflags, mode_t mode) { FAR struct tcbinfo_file_s *attr; finfo("Open '%s'\n", relpath); /* PROCFS is read-only. Any attempt to open with any kind of write * access is not permitted. * * REVISIT: Write-able proc files could be quite useful. */ if ((oflags & O_WRONLY) != 0 || (oflags & O_RDONLY) == 0) { ferr("ERROR: Only O_RDONLY supported\n"); return -EACCES; } /* Allocate a container to hold the file attributes */ attr = (FAR struct tcbinfo_file_s *) fs_heap_zalloc(sizeof(struct tcbinfo_file_s)); if (attr == NULL) { ferr("ERROR: Failed to allocate file attributes\n"); return -ENOMEM; } /* Save the attributes as the open-specific state in filep->f_priv */ filep->f_priv = (FAR void *)attr; return OK; } /**************************************************************************** * Name: tcbinfo_close ****************************************************************************/ static int tcbinfo_close(FAR struct file *filep) { FAR struct tcbinfo_file_s *attr; /* Recover our private data from the struct file instance */ attr = (FAR struct tcbinfo_file_s *)filep->f_priv; DEBUGASSERT(attr); /* Release the file attributes structure */ fs_heap_free(attr); filep->f_priv = NULL; return OK; } /**************************************************************************** * Name: tcbinfo_read ****************************************************************************/ static ssize_t tcbinfo_read(FAR struct file *filep, FAR char *buffer, size_t buflen) { FAR struct tcbinfo_file_s *attr; size_t linesize; off_t offset; ssize_t ret; finfo("buffer=%p buflen=%d\n", buffer, (int)buflen); /* Recover our private data from the struct file instance */ attr = (FAR struct tcbinfo_file_s *)filep->f_priv; DEBUGASSERT(attr); if (filep->f_pos == 0) { linesize = procfs_snprintf(attr->line, TCBINFO_LINELEN, "pointer %p size %zu\n", &g_tcbinfo, sizeof(struct tcbinfo_s)); /* Save the linesize in case we are re-entered with f_pos > 0 */ attr->linesize = linesize; } offset = filep->f_pos; ret = procfs_memcpy(attr->line, attr->linesize, buffer, buflen, &offset); /* Update the file offset */ if (ret > 0) { filep->f_pos += ret; } return ret; } /**************************************************************************** * Name: tcbinfo_dup * * Description: * Duplicate open file data in the new file structure. * ****************************************************************************/ static int tcbinfo_dup(FAR const struct file *oldp, FAR struct file *newp) { FAR struct tcbinfo_file_s *oldattr; FAR struct tcbinfo_file_s *newattr; finfo("Dup %p->%p\n", oldp, newp); /* Recover our private data from the old struct file instance */ oldattr = (FAR struct tcbinfo_file_s *)oldp->f_priv; DEBUGASSERT(oldattr); /* Allocate a new container to hold the task and attribute selection */ newattr = (FAR struct tcbinfo_file_s *) fs_heap_malloc(sizeof(struct tcbinfo_file_s)); if (!newattr) { ferr("ERROR: Failed to allocate file attributes\n"); return -ENOMEM; } /* The copy the file attributes from the old attributes to the new */ memcpy(newattr, oldattr, sizeof(struct tcbinfo_file_s)); /* Save the new attributes in the new file structure */ newp->f_priv = (FAR void *)newattr; return OK; } /**************************************************************************** * Name: tcbinfo_stat * * Description: Return information about a file or directory * ****************************************************************************/ static int tcbinfo_stat(FAR const char *relpath, FAR struct stat *buf) { /* "tcbinfo" is the name for a read-only file */ memset(buf, 0, sizeof(struct stat)); buf->st_mode = S_IFREG | S_IROTH | S_IRGRP | S_IRUSR; return OK; } /**************************************************************************** * Public Functions ****************************************************************************/ #endif /* !CONFIG_DISABLE_MOUNTPOINT && CONFIG_FS_PROCFS */