/* This file contains the code for performing four system calls relating to * status and directories. * * The entry points into this file are * do_chdir: perform the CHDIR system call * do_chroot: perform the CHROOT system call * do_stat: perform the STAT system call * do_fstat: perform the FSTAT system call * do_fstatfs: perform the FSTATFS system call * do_lstat: perform the LSTAT system call * * Changes for VFS: * Jul 2006 (Balazs Gerofi) */ #include "fs.h" #include #include #include #include #include #include "file.h" #include "fproc.h" #include "param.h" #include #include "vnode.h" #include "vmnt.h" FORWARD _PROTOTYPE( int change, (struct vnode **iip, char *name_ptr, int len)); FORWARD _PROTOTYPE( int change_into, (struct vnode **iip, struct vnode *vp)); /*===========================================================================* * do_fchdir * *===========================================================================*/ PUBLIC int do_fchdir() { /* Change directory on already-opened fd. */ struct filp *rfilp; int r; /* Is the file descriptor valid? */ if ( (rfilp = get_filp(m_in.fd)) == NIL_FILP) return(err_code); /* Is it a dir? */ if ((rfilp->filp_vno->v_mode & I_TYPE) != I_DIRECTORY) return ENOTDIR; /* Issue request and handle error */ r = forbidden(rfilp->filp_vno, X_BIT, 0 /*!use_realuid*/); if (r != OK) return r; rfilp->filp_vno->v_ref_count++; /* change_into expects a reference */ return change_into(&fp->fp_wd, rfilp->filp_vno); } /*===========================================================================* * do_chdir * *===========================================================================*/ PUBLIC int do_chdir() { /* Change directory. This function is also called by MM to simulate a chdir * in order to do EXEC, etc. It also changes the root directory, the uids and * gids, and the umask. */ int r; register struct fproc *rfp; if (who_e == PM_PROC_NR) { int slot; if(isokendpt(m_in.endpt1, &slot) != OK) return EINVAL; rfp = &fproc[slot]; put_vnode(fp->fp_rd); dup_vnode(fp->fp_rd = rfp->fp_rd); put_vnode(fp->fp_wd); dup_vnode(fp->fp_wd = rfp->fp_wd); /* MM uses access() to check permissions. To make this work, pretend * that the user's real ids are the same as the user's effective ids. * FS calls other than access() do not use the real ids, so are not * affected. */ fp->fp_realuid = fp->fp_effuid = rfp->fp_effuid; fp->fp_realgid = fp->fp_effgid = rfp->fp_effgid; fp->fp_umask = rfp->fp_umask; return(OK); } /* Perform the chdir(name) system call. */ r = change(&fp->fp_wd, m_in.name, m_in.name_length); return(r); } /*===========================================================================* * do_chroot * *===========================================================================*/ PUBLIC int do_chroot() { /* Perform the chroot(name) system call. */ register int r; if (!super_user) return(EPERM); /* only su may chroot() */ r = change(&fp->fp_rd, m_in.name, m_in.name_length); return(r); } /*===========================================================================* * change * *===========================================================================*/ PRIVATE int change(iip, name_ptr, len) struct vnode **iip; /* pointer to the inode pointer for the dir */ char *name_ptr; /* pointer to the directory name to change to */ int len; /* length of the directory name string */ { /* Do the actual work for chdir() and chroot(). */ struct vnode *vp; int r; if (fetch_name(name_ptr, len, M3) != OK) return(err_code); /* Request lookup */ if ((r = lookup_vp(0 /*flags*/, 0 /*!use_realuid*/, &vp)) != OK) return r; /* Is it a dir? */ if ((vp->v_mode & I_TYPE) != I_DIRECTORY) { put_vnode(vp); return ENOTDIR; } /* Access check */ r = forbidden(vp, X_BIT, 0 /*!use_realuid*/); if (r != OK) { put_vnode(vp); return r; } return change_into(iip, vp); } /*===========================================================================* * change_into * *===========================================================================*/ PRIVATE int change_into(iip, vp) struct vnode **iip; /* pointer to the inode pointer for the dir */ struct vnode *vp; /* this is what the inode has to become */ { /* Everything is OK. Make the change. */ put_vnode(*iip); /* release the old directory */ *iip = vp; /* acquire the new one */ return(OK); } /*===========================================================================* * do_stat * *===========================================================================*/ PUBLIC int do_stat() { /* Perform the stat(name, buf) system call. */ int r; struct vnode *vp; if (fetch_name(m_in.name1, m_in.name1_length, M1) != OK) return(err_code); /* Request lookup */ if ((r = lookup_vp(0 /*flags*/, 0 /*!use_realuid*/, &vp)) != OK) return r; /* Issue request */ r= req_stat(vp->v_fs_e, vp->v_inode_nr, who_e, m_in.name2, 0); put_vnode(vp); return r; } /*===========================================================================* * do_fstat * *===========================================================================*/ PUBLIC int do_fstat() { /* Perform the fstat(fd, buf) system call. */ register struct filp *rfilp; int pipe_pos = 0; /* Is the file descriptor valid? */ if ( (rfilp = get_filp(m_in.fd)) == NIL_FILP) { return(err_code); } /* If we read from a pipe, send position too */ pipe_pos= 0; if (rfilp->filp_vno->v_pipe == I_PIPE) { if (rfilp->filp_mode & R_BIT) if (ex64hi(rfilp->filp_pos) != 0) { panic(__FILE__, "do_fstat: bad position in pipe", NO_NUM); } pipe_pos = ex64lo(rfilp->filp_pos); } /* Issue request */ return req_stat(rfilp->filp_vno->v_fs_e, rfilp->filp_vno->v_inode_nr, who_e, m_in.buffer, pipe_pos); } /*===========================================================================* * do_fstatfs * *===========================================================================*/ PUBLIC int do_fstatfs() { /* Perform the fstatfs(fd, buf) system call. */ register struct filp *rfilp; /* Is the file descriptor valid? */ if ( (rfilp = get_filp(m_in.fd)) == NIL_FILP) return(err_code); /* Issue request */ return req_fstatfs(rfilp->filp_vno->v_fs_e, who_e, m_in.buffer); } /*===========================================================================* * do_lstat * *===========================================================================*/ PUBLIC int do_lstat() { /* Perform the lstat(name, buf) system call. */ struct vnode *vp; int r; if (fetch_name(m_in.name1, m_in.name1_length, M1) != OK) return(err_code); /* Request lookup */ if ((r = lookup_vp(PATH_RET_SYMLINK, 0 /*!use_realuid*/, &vp)) != OK) return r; /* Issue request */ r= req_stat(vp->v_fs_e, vp->v_inode_nr, who_e, m_in.name2, 0); put_vnode(vp); return r; }