From 1dd3220ea04b72f26438a239add08bb981f3b4d2 Mon Sep 17 00:00:00 2001 From: psptefhic <2945333274@qq.com> Date: Sun, 26 Jun 2022 17:03:17 +0800 Subject: [PATCH] getdents version 1 --- sys(getdents).c | 364 ++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 364 insertions(+) create mode 100644 sys(getdents).c diff --git a/sys(getdents).c b/sys(getdents).c new file mode 100644 index 0000000..89d2930 --- /dev/null +++ b/sys(getdents).c @@ -0,0 +1,364 @@ +/* + * linux/kernel/sys.c + * + * (C) 1991 Linus Torvalds + */ + +#include + +#include +#include +#include +#include +#include +#include + +struct linux_dirent +{ + long d_ino; + off_t d_off; + unsigned short d_reclen; + char d_name[14]; +}; + +int sys_ftime() +{ + return -ENOSYS; +} + +int sys_break() +{ + return -ENOSYS; +} + +int sys_ptrace() +{ + return -ENOSYS; +} + +int sys_stty() +{ + return -ENOSYS; +} + +int sys_gtty() +{ + return -ENOSYS; +} + +int sys_rename() +{ + return -ENOSYS; +} + +int sys_prof() +{ + return -ENOSYS; +} + +int sys_setregid(int rgid, int egid) +{ + if (rgid>0) { + if ((current->gid == rgid) || + suser()) + current->gid = rgid; + else + return(-EPERM); + } + if (egid>0) { + if ((current->gid == egid) || + (current->egid == egid) || + suser()) { + current->egid = egid; + current->sgid = egid; + } else + return(-EPERM); + } + return 0; +} + +int sys_setgid(int gid) +{ +/* return(sys_setregid(gid, gid)); */ + if (suser()) + current->gid = current->egid = current->sgid = gid; + else if ((gid == current->gid) || (gid == current->sgid)) + current->egid = gid; + else + return -EPERM; + return 0; +} + +int sys_acct() +{ + return -ENOSYS; +} + +int sys_phys() +{ + return -ENOSYS; +} + +int sys_lock() +{ + return -ENOSYS; +} + +int sys_mpx() +{ + return -ENOSYS; +} + +int sys_ulimit() +{ + return -ENOSYS; +} + +int sys_time(long * tloc) +{ + int i; + + i = CURRENT_TIME; + if (tloc) { + verify_area(tloc,4); + put_fs_long(i,(unsigned long *)tloc); + } + return i; +} + +/* + * Unprivileged users may change the real user id to the effective uid + * or vice versa. + */ +int sys_setreuid(int ruid, int euid) +{ + int old_ruid = current->uid; + + if (ruid>0) { + if ((current->euid==ruid) || + (old_ruid == ruid) || + suser()) + current->uid = ruid; + else + return(-EPERM); + } + if (euid>0) { + if ((old_ruid == euid) || + (current->euid == euid) || + suser()) { + current->euid = euid; + current->suid = euid; + } else { + current->uid = old_ruid; + return(-EPERM); + } + } + return 0; +} + +int sys_setuid(int uid) +{ +/* return(sys_setreuid(uid, uid)); */ + if (suser()) + current->uid = current->euid = current->suid = uid; + else if ((uid == current->uid) || (uid == current->suid)) + current->euid = uid; + else + return -EPERM; + return(0); +} + +int sys_stime(long * tptr) +{ + if (!suser()) + return -EPERM; + startup_time = get_fs_long((unsigned long *)tptr) - jiffies/HZ; + return 0; +} + +int sys_times(struct tms * tbuf) +{ + if (tbuf) { + verify_area(tbuf,sizeof *tbuf); + put_fs_long(current->utime,(unsigned long *)&tbuf->tms_utime); + put_fs_long(current->stime,(unsigned long *)&tbuf->tms_stime); + put_fs_long(current->cutime,(unsigned long *)&tbuf->tms_cutime); + put_fs_long(current->cstime,(unsigned long *)&tbuf->tms_cstime); + } + return jiffies; +} + +int sys_brk(unsigned long end_data_seg) +{ + if (end_data_seg >= current->end_code && + end_data_seg < current->start_stack - 16384) + current->brk = end_data_seg; + return current->brk; +} + +/* + * This needs some heave checking ... + * I just haven't get the stomach for it. I also don't fully + * understand sessions/pgrp etc. Let somebody who does explain it. + */ +int sys_setpgid(int pid, int pgid) +{ + int i; + + if (!pid) + pid = current->pid; + if (!pgid) + pgid = current->pid; + for (i=0 ; ipid==pid) { + if (task[i]->leader) + return -EPERM; + if (task[i]->session != current->session) + return -EPERM; + task[i]->pgrp = pgid; + return 0; + } + return -ESRCH; +} + +int sys_getpgrp(void) +{ + return current->pgrp; +} + +int sys_setsid(void) +{ + if (current->leader && !suser()) + return -EPERM; + current->leader = 1; + current->session = current->pgrp = current->pid; + current->tty = -1; + return current->pgrp; +} + +int sys_getgroups() +{ + return -ENOSYS; +} + +int sys_setgroups() +{ + return -ENOSYS; +} + +int sys_uname(struct utsname * name) +{ + static struct utsname thisname = { + "linux .0","nodename","release ","version ","machine " + }; + int i; + + if (!name) return -ERROR; + verify_area(name,sizeof *name); + for(i=0;iumask; + + current->umask = mask & 0777; + return (old); +} +int sys_sleep(unsigned int seconds) +{ + sys_signal(SIGALRM,SIG_IGN); + sys_alarm(seconds); + sys_pause(); + int lcs =sys_alarm(0); + return (lcs>0)?-1:0; +} +int sys_execve2(){ + return 0; +} +int sys_getcwd(){ + return 0; +} + +int sys_pipe2(){ + return 0; +} + +int sys_getdents(unsigned int fd, struct linux_dirent *dirent, unsigned int count) +{ + struct file *file; + struct m_inode *f_inode; + struct linux_dirent my_dirent; + struct buffer_head *block; + struct dir_entry *dir; + char *buf; + int num = 0; + file = current->filp[fd]; + if (!count) + return -1; + + f_inode = file->f_inode; + block = bread(f_inode->i_dev, f_inode->i_zone[0]); + + int k; + int len_dir = sizeof(struct dir_entry); + int len_dirent = sizeof(struct linux_dirent); + for (k = 0; k < f_inode->i_size; k += len_dir) + { + if (num + len_dirent >= count) + return 0; + + dir = (struct dir_entry *)(block->b_data + k); + if (dir->inode) + { + my_dirent.d_ino = dir->inode; + int i; + for (i = 0; i < NAME_LEN; i++) + my_dirent.d_name[i] = dir->name[i]; + my_dirent.d_off = 0; + my_dirent.d_reclen = sizeof(my_dirent); + buf = &my_dirent; + for (i = 0; i < my_dirent.d_reclen; i++) + { + put_fs_byte(*(buf + i), ((char *)dirent) + i + num); + } + num += my_dirent.d_reclen; + } + else + continue; + } + return num; +} \ No newline at end of file