fd.c /* * linux/fs/proc/fd.c * * Copyright (C) 1991, 1992 Linus Torvalds * * proc fd directory handling functions */ #include <asm/segment.h> #include <linux/errno.h> #include <linux/sched.h> #include <linux/proc_fs.h> #include <linux/stat.h> static int proc_readfd(struct inode *, struct file *, void *, filldir_t); static int proc_lookupfd(struct inode *,const char *,int,struct inode **); static struct file_operations proc_fd_operations = { NULL, /* lseek - default */ NULL, /* read - bad */ NULL, /* write - bad */ proc_readfd, /* readdir */ NULL, /* select - default */ NULL, /* ioctl - default */ NULL, /* mmap */ NULL, /* no special open code */ NULL, /* no special release code */ NULL /* can't fsync */ }; /* * proc directories can do almost nothing.. */ struct inode_operations proc_fd_inode_operations = { &proc_fd_operations, /* default base directory file-ops */ NULL, /* create */ proc_lookupfd, /* 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 */ }; static int proc_lookupfd(struct inode * dir, const char * name, int len, struct inode ** result) { unsigned int ino, pid, fd, c; struct task_struct * p; struct super_block * sb; int i; *result = NULL; ino = dir->i_ino; pid = ino >> 16; ino &= 0x0000ffff; if (!dir) return -ENOENT; sb = dir->i_sb; if (!pid || ino != PROC_PID_FD || !S_ISDIR(dir->i_mode)) { iput(dir); return -ENOENT; } if (!len || (name[0] == '.' && (len == 1 || (name[1] == '.' && len == 2)))) { if (len < 2) { *result = dir; return 0; } if (!(*result = proc_get_inode(sb, (pid << 16)+PROC_PID_INO, &proc_pid))) { iput(dir); return -ENOENT; } iput(dir); return 0; } iput(dir); fd = 0; while (len-- > 0) { c = *name - '0'; name++; if (c > 9) { fd = 0xfffff; break; } fd *= 10; fd += c; if (fd & 0xffff0000) { fd = 0xfffff; break; } } for (i = 0 ; i < NR_TASKS ; i++) if ((p = task[i]) && p->pid == pid) break; if (!pid || i >= NR_TASKS) return -ENOENT; if (fd >= NR_OPEN || !p->files->fd[fd] || !p->files->fd[fd]->f_inode) return -ENOENT; ino = (pid << 16) + (PROC_PID_FD_DIR << 8) + fd; if (!(*result = proc_get_inode(sb, ino, NULL))) return -ENOENT; return 0; } #define NUMBUF 10 static int proc_readfd(struct inode * inode, struct file * filp, void * dirent, filldir_t filldir) { char buf[NUMBUF]; int task_nr; struct task_struct * p; unsigned int fd, pid, ino; unsigned long i,j; if (!inode || !S_ISDIR(inode->i_mode)) return -EBADF; ino = inode->i_ino; pid = ino >> 16; ino &= 0x0000ffff; if (ino != PROC_PID_FD) return 0; for (fd = filp->f_pos; fd < 2; fd++, filp->f_pos++) { unsigned long ino = inode->i_ino; if (fd) ino = (ino & 0xffff0000) | PROC_PID_INO; if (filldir(dirent, "..", fd+1, fd, ino) < 0) return 0; } task_nr = 1; for (;;) { if ((p = task[task_nr]) && p->pid == pid) break; if (++task_nr >= NR_TASKS) return 0; } for (fd -= 2 ; fd < NR_OPEN; fd++, filp->f_pos++) { if (!p->files) break; if (!p->files->fd[fd] || !p->files->fd[fd]->f_inode) continue; j = NUMBUF; i = fd; do { j--; buf[j] = '0' + (i % 10); i /= 10; } while (i); ino = (pid << 16) + (PROC_PID_FD_DIR << 8) + fd; if (filldir(dirent, buf+j, NUMBUF-j, fd+2, ino) < 0) break; /* filldir() might have slept, so we must re-validate "p" */ if (p != task[task_nr] || p->pid != pid) break; } return 0; }