/* * proc/fs/generic.c --- generic routines for the proc-fs * * This file contains generic proc-fs routines for handling * directories and files. * * Copyright (C) 1991, 1992 Linus Torvalds. * Copyright (C) 1997 Theodore Ts'o */ #include #include #include #include #include #include static long proc_file_read(struct inode * inode, struct file * file, char * buf, unsigned long nbytes); static long proc_file_write(struct inode * inode, struct file * file, const char * buffer, unsigned long count); static long long proc_file_lseek(struct inode * inode, struct file * file, long long offset, int orig); static struct file_operations proc_file_operations = { proc_file_lseek, /* lseek */ proc_file_read, /* read */ proc_file_write, /* write */ NULL, /* readdir */ NULL, /* poll */ NULL, /* ioctl */ NULL, /* mmap */ NULL, /* no special open code */ NULL, /* no special release code */ NULL /* can't fsync */ }; /* * proc files can do almost nothing.. */ struct inode_operations proc_file_inode_operations = { &proc_file_operations, /* default proc file-ops */ NULL, /* create */ NULL, /* lookup */ NULL, /* link */ NULL, /* unlink */ NULL, /* symlink */ NULL, /* mkdir */ NULL, /* rmdir */ NULL, /* mknod */ NULL, /* rename */ NULL, /* readlink */ NULL, /* follow_link */ NULL, /* readpage */ NULL, /* writepage */ NULL, /* bmap */ NULL, /* truncate */ NULL /* permission */ }; /* * compatibility to replace fs/proc/net.c */ struct inode_operations proc_net_inode_operations = { &proc_file_operations, /* default net file-ops */ NULL, /* create */ NULL, /* lookup */ NULL, /* link */ NULL, /* unlink */ NULL, /* symlink */ NULL, /* mkdir */ NULL, /* rmdir */ NULL, /* mknod */ NULL, /* rename */ NULL, /* readlink */ NULL, /* follow_link */ NULL, /* readpage */ NULL, /* writepage */ NULL, /* bmap */ NULL, /* truncate */ NULL /* permission */ }; #ifndef MIN #define MIN(a,b) (((a) < (b)) ? (a) : (b)) #endif /* 4K page size but our output routines use some slack for overruns */ #define PROC_BLOCK_SIZE (3*1024) static long proc_file_read(struct inode * inode, struct file * file, char * buf, unsigned long nbytes) { char *page; int retval=0; int eof=0; int n, count; char *start; struct proc_dir_entry * dp; if (nbytes < 0) return -EINVAL; dp = (struct proc_dir_entry *) inode->u.generic_ip; if (!(page = (char*) __get_free_page(GFP_KERNEL))) return -ENOMEM; while ((nbytes > 0) && !eof) { count = MIN(PROC_BLOCK_SIZE, nbytes); start = NULL; if (dp->get_info) { /* * Handle backwards compatibility with the old net * routines. * * XXX What gives with the file->f_flags & O_ACCMODE * test? Seems stupid to me.... */ n = dp->get_info(page, &start, file->f_pos, count, (file->f_flags & O_ACCMODE) == O_RDWR); if (n < count) eof = 1; } else if (dp->read_proc) { n = dp->read_proc(page, &start, file->f_pos, count, &eof, dp->data); } else break; if (!start) { /* * For proc files that are less than 4k */ start = page + file->f_pos; n -= file->f_pos; if (n <= 0) break; if (n > count) n = count; } if (n == 0) break; /* End of file */ if (n < 0) { if (retval == 0) retval = n; break; } n -= copy_to_user(buf, start, n); if (n == 0) { if (retval == 0) retval = -EFAULT; break; } file->f_pos += n; /* Move down the file */ nbytes -= n; buf += n; retval += n; } free_page((unsigned long) page); return retval; } static long proc_file_write(struct inode * inode, struct file * file, const char * buffer, unsigned long count) { struct proc_dir_entry * dp; if (count < 0) return -EINVAL; dp = (struct proc_dir_entry *) inode->u.generic_ip; if (!dp->write_proc) return -EIO; return dp->write_proc(file, buffer, count, dp->data); } static long long proc_file_lseek(struct inode * inode, struct file * file, long long offset, int orig) { switch (orig) { case 0: file->f_pos = offset; return(file->f_pos); case 1: file->f_pos += offset; return(file->f_pos); case 2: return(-EINVAL); default: return(-EINVAL); } } /* * This function parses a name such as "tty/driver/serial", and * returns the struct proc_dir_entry for "/proc/tty/driver", and * returns "serial" in residual. */ static int xlate_proc_name(const char *name, struct proc_dir_entry **ret, const char **residual) { const char *cp = name, *next; struct proc_dir_entry *de; int len; de = &proc_root; while (1) { next = strchr(cp, '/'); if (!next) break; len = next - cp; for (de = de->subdir; de ; de = de->next) { if (proc_match(len, cp, de)) break; } if (!de) return -ENOENT; cp += len + 1; } *residual = cp; *ret = de; return 0; } struct proc_dir_entry *create_proc_entry(const char *name, mode_t mode, struct proc_dir_entry *parent) { struct proc_dir_entry *ent; const char *fn; if (parent) fn = name; else { if (xlate_proc_name(name, &parent, &fn)) return NULL; } ent = kmalloc(sizeof(struct proc_dir_entry), GFP_KERNEL); if (!ent) return NULL; memset(ent, 0, sizeof(struct proc_dir_entry)); if (mode == S_IFDIR) mode |= S_IRUGO | S_IXUGO; else if (mode == 0) mode = S_IFREG | S_IRUGO; ent->name = fn; ent->namelen = strlen(fn); ent->mode = mode; if (S_ISDIR(mode)) ent->nlink = 2; else ent->nlink = 1; proc_register(parent, ent); return ent; } void remove_proc_entry(const char *name, struct proc_dir_entry *parent) { struct proc_dir_entry *de; const char *fn; int len; if (parent) fn = name; else if (xlate_proc_name(name, &parent, &fn)) return; len = strlen(fn); for (de = parent->subdir; de ; de = de->next) { if (proc_match(len, fn, de)) break; } if (de) proc_unregister(parent, de->low_ino); kfree(de); }