123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176177178179180181182183184185186187188189190191192193194195196197198199200201202203204205206207208209210211212213214215216217218219220221222223224225226227228229230231232233234235236237238239240241242243244245246247248249250251252253254255256257258259260261262263264265266267268269270271272273274275276277278279280281282283284285286287288289290291292293294295296297298299300301302303304305306307308309310311312313314315316317318319320321322323324325326327328329330331332333334335336337338339340341342343344345346347348349350351352353354355356357358359360361362363364365366367368369370371372373374375376377378379380381382383384385386387388389390391392393394395396397398399400401402403404405406407408409410411412413414415416417418419420421422423424425426427428429430431432433434435436437438439440441442443444445446447448449450451452453454455456457458459460461462463464465466467 |
- /* -*- mode:c; c-file-style:"k&r"; c-basic-offset: 4; tab-width:4; indent-tabs-mode:nil; mode:auto-fill; fill-column:78; -*- */
- /* vim: set ts=4 sw=4 et tw=78 fo=cqt wm=0: */
- /* Copyright (C) 2014 Stony Brook University
- This file is part of Graphene Library OS.
- Graphene Library OS is free software: you can redistribute it and/or
- modify it under the terms of the GNU Lesser General Public License
- as published by the Free Software Foundation, either version 3 of the
- License, or (at your option) any later version.
- Graphene Library OS is distributed in the hope that it will be useful,
- but WITHOUT ANY WARRANTY; without even the implied warranty of
- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- GNU Lesser General Public License for more details.
- You should have received a copy of the GNU Lesser General Public License
- along with this program. If not, see <http://www.gnu.org/licenses/>. */
- /*
- * fs.c
- *
- * This file contains codes for implementation of 'dev' filesystem.
- */
- #include <shim_internal.h>
- #include <shim_handle.h>
- #include <shim_fs.h>
- #include <shim_utils.h>
- #include <shim_profile.h>
- #include <pal.h>
- #include <pal_error.h>
- #include <errno.h>
- #include <linux/stat.h>
- #include <linux/fcntl.h>
- #include <asm/fcntl.h>
- #include <asm/mman.h>
- #include <asm/unistd.h>
- #include <asm/prctl.h>
- #define EMPTY_DEV_OPS \
- { \
- .open = NULL, \
- .close = NULL, \
- .read = NULL, \
- .write = NULL, \
- .flush = NULL, \
- .seek = NULL, \
- .truncate = NULL, \
- .mode = NULL, \
- .stat = NULL, \
- .hstat = NULL, \
- }
- #define DEV_INO_BASE 1025
- static int dev_null_read (struct shim_handle * hdl, void * buf,
- size_t count)
- {
- return 0;
- }
- static int dev_zero_read (struct shim_handle * hdl, void * buf,
- size_t count)
- {
- memset(buf, 0, count);
- return count;
- }
- static int dev_null_write (struct shim_handle * hdl, const void * buf,
- size_t count)
- {
- return count;
- }
- static int dev_null_mode (const char * name, mode_t * mode)
- {
- *mode = 0666|S_IFCHR;
- return 0;
- }
- static int dev_null_stat (const char * name, struct stat * stat)
- {
- stat->st_mode = 0666|S_IFCHR;
- stat->st_uid = 0;
- stat->st_gid = 0;
- stat->st_size = 0;
- stat->st_blksize = 0;
- return 0;
- }
- static int dev_null_hstat (struct shim_handle * hdl, struct stat * stat)
- {
- stat->st_mode = 0666|S_IFCHR;
- stat->st_uid = 0;
- stat->st_gid = 0;
- stat->st_size = 0;
- stat->st_blksize = 0;
- return 0;
- }
- static int dev_null_truncate (struct shim_handle * hdl, uint64_t size)
- {
- return 0;
- }
- static int dev_random_mode (const char * name, mode_t * mode)
- {
- *mode = 0666|S_IFCHR;
- return 0;
- }
- static int dev_random_read (struct shim_handle * hdl, void * buf,
- size_t count)
- {
- int rv;
- rv = DkRandomBitsRead(buf, count);
- return rv;
- }
- static int dev_urandom_read (struct shim_handle * hdl, void * buf,
- size_t count)
- {
- int rv;
- rv = getrand(buf, count);
- return rv;
- }
- static int dev_random_stat (const char * name, struct stat * stat)
- {
- stat->st_mode = 0666|S_IFCHR;
- stat->st_uid = 0;
- stat->st_gid = 0;
- stat->st_size = 0;
- stat->st_blksize = 0;
- return 0;
- }
- static int dev_random_hstat (struct shim_handle * hdl, struct stat * stat)
- {
- stat->st_mode = 0444|S_IFCHR;
- stat->st_uid = 0;
- stat->st_gid = 0;
- stat->st_size = 0;
- stat->st_blksize = 0;
- return 0;
- }
- static int search_dev_driver (const char * name, struct shim_dev_ops * ops)
- {
- if (strcmp_static(name, "null") || strcmp_static(name, "tty")) {
- if (ops)
- ops->read = &dev_null_read;
- null_dev:
- if (ops) {
- ops->write = &dev_null_write;
- ops->truncate = &dev_null_truncate;
- ops->mode = &dev_null_mode;
- ops->stat = &dev_null_stat;
- ops->hstat = &dev_null_hstat;
- }
- return 0;
- }
- if (strcmp_static(name, "zero")) {
- if (ops)
- ops->read = &dev_zero_read;
- goto null_dev;
- }
- if (strcmp_static(name, "random")) {
- if (ops)
- ops->read = &dev_random_read;
- random_dev:
- if (ops) {
- ops->mode = &dev_random_mode;
- ops->stat = &dev_random_stat;
- ops->hstat = &dev_random_hstat;
- }
- return 0;
- }
- if (strcmp_static(name, "urandom")) {
- if (ops)
- ops->read = &dev_urandom_read;
- goto random_dev;
- }
- if (strcmp_static(name, "stdin") || strcmp_static(name, "stdout") ||
- strcmp_static(name, "stderr"))
- return -EISLINK;
- return -ENOENT;
- }
- static int dev_mount (const char * uri, const char * root, void ** mount_data)
- {
- /* do nothing */
- return 0;
- }
- static int dev_unmount (void * mount_data)
- {
- /* do nothing */
- return 0;
- }
- static int dev_open (struct shim_handle * hdl, struct shim_dentry * dent,
- int flags)
- {
- struct shim_dev_ops ops_buf = EMPTY_DEV_OPS;
- int ret = search_dev_driver(qstrgetstr(&dent->rel_path), &ops_buf);
- if (ret < 0)
- return ret;
- hdl->type = TYPE_DEV;
- hdl->flags = flags & ~O_ACCMODE;
- hdl->acc_mode = ACC_MODE(flags & O_ACCMODE);
- memcpy(&hdl->info.dev.dev_ops, &ops_buf,
- sizeof(struct shim_dev_ops));
- if (!ops_buf.read && (hdl->acc_mode & MAY_READ))
- return -EACCES;
- if (!ops_buf.write && (hdl->acc_mode & MAY_WRITE))
- return -EACCES;
- if (ops_buf.open)
- return ops_buf.open(hdl, qstrgetstr(&dent->rel_path), flags);
- return 0;
- }
- static int dev_lookup (struct shim_dentry * dent, bool force)
- {
- if (qstrempty(&dent->rel_path)) {
- dent->state |= DENTRY_ISDIRECTORY;
- dent->ino = DEV_INO_BASE;
- return 0;
- }
- /* we don't care about forced or not */
- return search_dev_driver(qstrgetstr(&dent->rel_path), NULL);
- }
- static int dev_mode (struct shim_dentry * dent, mode_t * mode, bool force)
- {
- if (qstrempty(&dent->rel_path)) {
- dent->ino = DEV_INO_BASE;
- *mode = 0555|S_IFDIR;
- return 0;
- }
- /* we don't care about forced or not */
- struct shim_dev_ops ops_buf = EMPTY_DEV_OPS;
- int ret = search_dev_driver(qstrgetstr(&dent->rel_path), &ops_buf);
- if (ret < 0)
- return ret;
- return ops_buf.mode(qstrgetstr(&dent->rel_path), mode);
- }
- static int dev_flush (struct shim_handle * hdl)
- {
- if (!hdl->info.dev.dev_ops.flush)
- return 0;
- return hdl->info.dev.dev_ops.flush(hdl);
- }
- static int dev_close (struct shim_handle * hdl)
- {
- if (!hdl->info.dev.dev_ops.close)
- return 0;
- return hdl->info.dev.dev_ops.close(hdl);
- }
- static int dev_read (struct shim_handle * hdl, void * buf,
- size_t count)
- {
- if (!hdl->info.dev.dev_ops.read)
- return -EACCES;
- return hdl->info.dev.dev_ops.read(hdl, buf, count);
- }
- static int dev_write (struct shim_handle * hdl, const void * buf,
- size_t count)
- {
- if (!hdl->info.dev.dev_ops.write)
- return -EACCES;
- return hdl->info.dev.dev_ops.write(hdl, buf, count);
- }
- static int dev_seek (struct shim_handle * hdl, off_t offset, int wence)
- {
- if (!hdl->info.dev.dev_ops.seek)
- return -EACCES;
- return hdl->info.dev.dev_ops.seek(hdl, offset, wence);
- }
- static int dev_truncate (struct shim_handle * hdl, uint64_t len)
- {
- if (!hdl->info.dev.dev_ops.truncate)
- return -EACCES;
- return hdl->info.dev.dev_ops.truncate(hdl, len);
- }
- static int dev_readdir (struct shim_dentry * dent, struct shim_dirent ** dirent)
- {
- if (!qstrempty(&dent->rel_path)) {
- struct shim_dev_ops ops_buf = EMPTY_DEV_OPS;
- int ret = search_dev_driver(qstrgetstr(&dent->rel_path), &ops_buf);
- if (ret < 0 && ret != -EISLINK)
- return ret;
- return -ENOTDIR;
- }
- struct shim_dirent * buf, * ptr;
- int buf_size = MAX_PATH;
- retry:
- buf = malloc(buf_size);
- *dirent = ptr = buf;
- struct shim_dirent ** last = dirent;
- #define copy_entry(devname, devtype) \
- do { \
- int name_len = strlen(devname); \
- \
- if ((void *) (ptr + 1) + name_len + 1 > \
- (void *) buf + buf_size) \
- goto nomem; \
- \
- ptr->next = (void *) (ptr + 1) + name_len + 1; \
- ptr->ino = 1; \
- ptr->type = (devtype); \
- memcpy(ptr->name, (devname), name_len + 1); \
- last = &ptr->next; \
- ptr = ptr->next; \
- } while (0)
- copy_entry("null", LINUX_DT_CHR);
- copy_entry("zero", LINUX_DT_CHR);
- copy_entry("stdin", LINUX_DT_LNK);
- copy_entry("stdout", LINUX_DT_LNK);
- copy_entry("stderr", LINUX_DT_LNK);
- *last = NULL;
- return 0;
- nomem:
- buf_size *= 2;
- free(buf);
- goto retry;
- }
- static int dev_stat (struct shim_dentry * dent, struct stat * buf)
- {
- if (qstrempty(&dent->rel_path)) {
- buf->st_dev = DEV_INO_BASE;
- buf->st_ino = DEV_INO_BASE;
- buf->st_mode = 0777|S_IFDIR;
- buf->st_size = 4096;
- buf->st_blksize = 4096;
- return 0;
- }
- struct shim_dev_ops ops_buf = EMPTY_DEV_OPS;
- int ret = search_dev_driver(qstrgetstr(&dent->rel_path), &ops_buf);
- if (ret < 0 && ret != -EISLINK)
- return ret;
- if (ret == -EISLINK) {
- buf->st_dev = DEV_INO_BASE;
- buf->st_ino = DEV_INO_BASE;
- buf->st_mode = 0777|S_IFLNK;
- buf->st_size = 0;
- buf->st_blksize = 0;
- return 0;
- }
- buf->st_dev = DEV_INO_BASE;
- buf->st_ino = DEV_INO_BASE;
- return ops_buf.stat ? ops_buf.stat(qstrgetstr(&dent->rel_path), buf) :
- -EACCES;
- }
- static int dev_hstat (struct shim_handle * hdl, struct stat * buf)
- {
- if (!hdl->info.dev.dev_ops.hstat)
- return -EACCES;
- return hdl->info.dev.dev_ops.hstat(hdl, buf);
- }
- static int dev_poll (struct shim_handle * hdl, int poll_type)
- {
- if (poll_type == FS_POLL_SZ)
- return 0;
- int ret = 0;
- if ((poll_type & FS_POLL_RD) && hdl->info.dev.dev_ops.read)
- ret |= FS_POLL_RD;
- if ((poll_type & FS_POLL_WR) && hdl->info.dev.dev_ops.write)
- ret |= FS_POLL_WR;
- return ret;
- }
- static int dev_follow_link (struct shim_dentry * dent, struct shim_qstr * link)
- {
- const char * name = qstrgetstr(&dent->rel_path);
- if (strcmp_static(name, "stdin")) {
- qstrsetstr(link, "/proc/self/0", static_strlen("/proc/self/0"));
- return 0;
- } else if (strcmp_static(name, "stdout")) {
- qstrsetstr(link, "/proc/self/1", static_strlen("/proc/self/1"));
- return 0;
- } else if (strcmp_static(name, "stderr")) {
- qstrsetstr(link, "/proc/self/2", static_strlen("/proc/self/2"));
- return 0;
- }
- if (strcmp_static(name, "null") || strcmp_static(name, "zero"))
- return -ENOTLINK;
- return -ENOENT;
- }
- struct shim_fs_ops dev_fs_ops = {
- .mount = &dev_mount,
- .unmount = &dev_unmount,
- .flush = &dev_flush,
- .close = &dev_close,
- .read = &dev_read,
- .write = &dev_write,
- .seek = &dev_seek,
- .hstat = &dev_hstat,
- .poll = &dev_poll,
- .truncate = &dev_truncate,
- };
- struct shim_d_ops dev_d_ops = {
- .open = &dev_open,
- .lookup = &dev_lookup,
- .mode = &dev_mode,
- .readdir = &dev_readdir,
- .stat = &dev_stat,
- .follow_link = &dev_follow_link,
- };
|