diff options
Diffstat (limited to 'fs/proc')
| -rw-r--r-- | fs/proc/Makefile | 2 | ||||
| -rw-r--r-- | fs/proc/generic.c | 2 | ||||
| -rw-r--r-- | fs/proc/inode.c | 1 | ||||
| -rw-r--r-- | fs/proc/internal.h | 2 | ||||
| -rw-r--r-- | fs/proc/proc_sysctl.c | 478 | ||||
| -rw-r--r-- | fs/proc/root.c | 10 |
6 files changed, 486 insertions, 9 deletions
diff --git a/fs/proc/Makefile b/fs/proc/Makefile index f6c776272572..a6b3a8f878f0 100644 --- a/fs/proc/Makefile +++ b/fs/proc/Makefile @@ -8,7 +8,7 @@ proc-y := nommu.o task_nommu.o proc-$(CONFIG_MMU) := mmu.o task_mmu.o proc-y += inode.o root.o base.o generic.o array.o \ - proc_tty.o proc_misc.o + proc_tty.o proc_misc.o proc_sysctl.o proc-$(CONFIG_PROC_KCORE) += kcore.o proc-$(CONFIG_PROC_VMCORE) += vmcore.o diff --git a/fs/proc/generic.c b/fs/proc/generic.c index 0cdc00d9d97e..775fb21294d8 100644 --- a/fs/proc/generic.c +++ b/fs/proc/generic.c @@ -32,7 +32,7 @@ static loff_t proc_file_lseek(struct file *, loff_t, int); DEFINE_SPINLOCK(proc_subdir_lock); -int proc_match(int len, const char *name, struct proc_dir_entry *de) +static int proc_match(int len, const char *name, struct proc_dir_entry *de) { if (de->namelen != len) return 0; diff --git a/fs/proc/inode.c b/fs/proc/inode.c index f6722be37dde..c372eb151a3a 100644 --- a/fs/proc/inode.c +++ b/fs/proc/inode.c @@ -161,6 +161,7 @@ struct inode *proc_get_inode(struct super_block *sb, unsigned int ino, if (!inode) goto out_ino; + PROC_I(inode)->fd = 0; PROC_I(inode)->pde = de; if (de) { if (de->mode) { diff --git a/fs/proc/internal.h b/fs/proc/internal.h index 277dcd66ebe2..c932aa65e198 100644 --- a/fs/proc/internal.h +++ b/fs/proc/internal.h @@ -11,6 +11,8 @@ #include <linux/proc_fs.h> +extern int proc_sys_init(void); + struct vmalloc_info { unsigned long used; unsigned long largest_chunk; diff --git a/fs/proc/proc_sysctl.c b/fs/proc/proc_sysctl.c new file mode 100644 index 000000000000..bb16a1e78826 --- /dev/null +++ b/fs/proc/proc_sysctl.c @@ -0,0 +1,478 @@ +/* + * /proc/sys support + */ + +#include <linux/sysctl.h> +#include <linux/proc_fs.h> +#include <linux/security.h> +#include "internal.h" + +static struct dentry_operations proc_sys_dentry_operations; +static const struct file_operations proc_sys_file_operations; +static struct inode_operations proc_sys_inode_operations; + +static void proc_sys_refresh_inode(struct inode *inode, struct ctl_table *table) +{ + /* Refresh the cached information bits in the inode */ + if (table) { + inode->i_uid = 0; + inode->i_gid = 0; + inode->i_mode = table->mode; + if (table->proc_handler) { + inode->i_mode |= S_IFREG; + inode->i_nlink = 1; + } else { + inode->i_mode |= S_IFDIR; + inode->i_nlink = 0; /* It is too hard to figure out */ + } + } +} + +static struct inode *proc_sys_make_inode(struct inode *dir, struct ctl_table *table) +{ + struct inode *inode; + struct proc_inode *dir_ei, *ei; + int depth; + + inode = new_inode(dir->i_sb); + if (!inode) + goto out; + + /* A directory is always one deeper than it's parent */ + dir_ei = PROC_I(dir); + depth = dir_ei->fd + 1; + + ei = PROC_I(inode); + ei->fd = depth; + inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME; + inode->i_op = &proc_sys_inode_operations; + inode->i_fop = &proc_sys_file_operations; + proc_sys_refresh_inode(inode, table); +out: + return inode; +} + +static struct dentry *proc_sys_ancestor(struct dentry *dentry, int depth) +{ + for (;;) { + struct proc_inode *ei; + + ei = PROC_I(dentry->d_inode); + if (ei->fd == depth) + break; /* found */ + + dentry = dentry->d_parent; + } + return dentry; +} + +static struct ctl_table *proc_sys_lookup_table_one(struct ctl_table *table, + struct qstr *name) +{ + int len; + for ( ; table->ctl_name || table->procname; table++) { + + if (!table->procname) + continue; + + len = strlen(table->procname); + if (len != name->len) + continue; + + if (memcmp(table->procname, name->name, len) != 0) + continue; + + /* I have a match */ + return table; + } + return NULL; +} + +static struct ctl_table *proc_sys_lookup_table(struct dentry *dentry, + struct ctl_table *table) +{ + struct dentry *ancestor; + struct proc_inode *ei; + int depth, i; + + ei = PROC_I(dentry->d_inode); + depth = ei->fd; + + if (depth == 0) + return table; + + for (i = 1; table && (i <= depth); i++) { + ancestor = proc_sys_ancestor(dentry, i); + table = proc_sys_lookup_table_one(table, &ancestor->d_name); + if (table) + table = table->child; + } + return table; + +} +static struct ctl_table *proc_sys_lookup_entry(struct dentry *dparent, + struct qstr *name, + struct ctl_table *table) +{ + table = proc_sys_lookup_table(dparent, table); + if (table) + table = proc_sys_lookup_table_one(table, name); + return table; +} + +static struct ctl_table *do_proc_sys_lookup(struct dentry *parent, + struct qstr *name, + struct ctl_table_header **ptr) +{ + struct ctl_table_header *head; + struct ctl_table *table = NULL; + + for (head = sysctl_head_next(NULL); head; + head = sysctl_head_next(head)) { + table = proc_sys_lookup_entry(parent, name, head->ctl_table); + if (table) + break; + } + *ptr = head; + return table; +} + +static struct dentry *proc_sys_lookup(struct inode *dir, struct dentry *dentry, + struct nameidata *nd) +{ + struct ctl_table_header *head; + struct inode *inode; + struct dentry *err; + struct ctl_table *table; + + err = ERR_PTR(-ENOENT); + table = do_proc_sys_lookup(dentry->d_parent, &dentry->d_name, &head); + if (!table) + goto out; + + err = ERR_PTR(-ENOMEM); + inode = proc_sys_make_inode(dir, table); + if (!inode) + goto out; + + err = NULL; + dentry->d_op = &proc_sys_dentry_operations; + d_add(dentry, inode); + +out: + sysctl_head_finish(head); + return err; +} + +static ssize_t proc_sys_read(struct file *filp, char __user *buf, + size_t count, loff_t *ppos) +{ + struct dentry *dentry = filp->f_dentry; + struct ctl_table_header *head; + struct ctl_table *table; + ssize_t error, res; + + table = do_proc_sys_lookup(dentry->d_parent, &dentry->d_name, &head); + /* Has the sysctl entry disappeared on us? */ + error = -ENOENT; + if (!table) + goto out; + + /* Has the sysctl entry been replaced by a directory? */ + error = -EISDIR; + if (!table->proc_handler) + goto out; + + /* + * At this point we know that the sysctl was not unregistered + * and won't be until we finish. + */ + error = -EPERM; + if (sysctl_perm(table, MAY_READ)) + goto out; + + /* careful: calling conventions are nasty here */ + res = count; + error = table->proc_handler(table, 0, filp, buf, &res, ppos); + if (!error) + error = res; +out: + sysctl_head_finish(head); + + return error; +} + +static ssize_t proc_sys_write(struct file *filp, const char __user *buf, + size_t count, loff_t *ppos) +{ + struct dentry *dentry = filp->f_dentry; + struct ctl_table_header *head; + struct ctl_table *table; + ssize_t error, res; + + table = do_proc_sys_lookup(dentry->d_parent, &dentry->d_name, &head); + /* Has the sysctl entry disappeared on us? */ + error = -ENOENT; + if (!table) + goto out; + + /* Has the sysctl entry been replaced by a directory? */ + error = -EISDIR; + if (!table->proc_handler) + goto out; + + /* + * At this point we know that the sysctl was not unregistered + * and won't be until we finish. + */ + error = -EPERM; + if (sysctl_perm(table, MAY_WRITE)) + goto out; + + /* careful: calling conventions are nasty here */ + res = count; + error = table->proc_handler(table, 1, filp, (char __user *)buf, + &res, ppos); + if (!error) + error = res; +out: + sysctl_head_finish(head); + + return error; +} + + +static int proc_sys_fill_cache(struct file *filp, void *dirent, + filldir_t filldir, struct ctl_table *table) +{ + struct ctl_table_header *head; + struct ctl_table *child_table = NULL; + struct dentry *child, *dir = filp->f_path.dentry; + struct inode *inode; + struct qstr qname; + ino_t ino = 0; + unsigned type = DT_UNKNOWN; + int ret; + + qname.name = table->procname; + qname.len = strlen(table->procname); + qname.hash = full_name_hash(qname.name, qname.len); + + /* Suppress duplicates. + * Only fill a directory entry if it is the value that + * an ordinary lookup of that name returns. Hide all + * others. + * + * If we ever cache this translation in the dcache + * I should do a dcache lookup first. But for now + * it is just simpler not to. + */ + ret = 0; + child_table = do_proc_sys_lookup(dir, &qname, &head); + sysctl_head_finish(head); + if (child_table != table) + return 0; + + child = d_lookup(dir, &qname); + if (!child) { + struct dentry *new; + new = d_alloc(dir, &qname); + if (new) { + inode = proc_sys_make_inode(dir->d_inode, table); + if (!inode) + child = ERR_PTR(-ENOMEM); + else { + new->d_op = &proc_sys_dentry_operations; + d_add(new, inode); + } + if (child) + dput(new); + else + child = new; + } + } + if (!child || IS_ERR(child) || !child->d_inode) + goto end_instantiate; + inode = child->d_inode; + if (inode) { + ino = inode->i_ino; + type = inode->i_mode >> 12; + } + dput(child); +end_instantiate: + if (!ino) + ino= find_inode_number(dir, &qname); + if (!ino) + ino = 1; + return filldir(dirent, qname.name, qname.len, filp->f_pos, ino, type); +} + +static int proc_sys_readdir(struct file *filp, void *dirent, filldir_t filldir) +{ + struct dentry *dentry = filp->f_dentry; + struct inode *inode = dentry->d_inode; + struct ctl_table_header *head = NULL; + struct ctl_table *table; + unsigned long pos; + int ret; + + ret = -ENOTDIR; + if (!S_ISDIR(inode->i_mode)) + goto out; + + ret = 0; + /* Avoid a switch here: arm builds fail with missing __cmpdi2 */ + if (filp->f_pos == 0) { + if (filldir(dirent, ".", 1, filp->f_pos, + inode->i_ino, DT_DIR) < 0) + goto out; + filp->f_pos++; + } + if (filp->f_pos == 1) { + if (filldir(dirent, "..", 2, filp->f_pos, + parent_ino(dentry), DT_DIR) < 0) + goto out; + filp->f_pos++; + } + pos = 2; + + /* - Find each instance of the directory + * - Read all entries in each instance + * - Before returning an entry to user space lookup the entry + * by name and if I find a different entry don't return + * this one because it means it is a buried dup. + * For sysctl this should only happen for directory entries. + */ + for (head = sysctl_head_next(NULL); head; head = sysctl_head_next(head)) { + table = proc_sys_lookup_table(dentry, head->ctl_table); + + if (!table) + continue; + + for (; table->ctl_name || table->procname; table++, pos++) { + /* Can't do anything without a proc name */ + if (!table->procname) + continue; + + if (pos < filp->f_pos) + continue; + + if (proc_sys_fill_cache(filp, dirent, filldir, table) < 0) + goto out; + filp->f_pos = pos + 1; + } + } + ret = 1; +out: + sysctl_head_finish(head); + return ret; +} + +static int proc_sys_permission(struct inode *inode, int mask, struct nameidata *nd) +{ + /* + * sysctl entries that are not writeable, + * are _NOT_ writeable, capabilities or not. + */ + struct ctl_table_header *head; + struct ctl_table *table; + struct dentry *dentry; + int mode; + int depth; + int error; + + head = NULL; + depth = PROC_I(inode)->fd; + + /* First check the cached permissions, in case we don't have + * enough information to lookup the sysctl table entry. + */ + error = -EACCES; + mode = inode->i_mode; + + if (current->euid == 0) + mode >>= 6; + else if (in_group_p(0)) + mode >>= 3; + + if ((mode & mask & (MAY_READ|MAY_WRITE|MAY_EXEC)) == mask) + error = 0; + + /* If we can't get a sysctl table entry the permission + * checks on the cached mode will have to be enough. + */ + if (!nd || !depth) + goto out; + + dentry = nd->dentry; + table = do_proc_sys_lookup(dentry->d_parent, &dentry->d_name, &head); + + /* If the entry does not exist deny permission */ + error = -EACCES; + if (!table) + goto out; + + /* Use the permissions on the sysctl table entry */ + error = sysctl_perm(table, mask); +out: + sysctl_head_finish(head); + return error; +} + +static int proc_sys_setattr(struct dentry *dentry, struct iattr *attr) +{ + struct inode *inode = dentry->d_inode; + int error; + + if (attr->ia_valid & (ATTR_MODE | ATTR_UID | ATTR_GID)) + return -EPERM; + + error = inode_change_ok(inode, attr); + if (!error) { + error = security_inode_setattr(dentry, attr); + if (!error) + error = inode_setattr(inode, attr); + } + + return error; +} + +/* I'm lazy and don't distinguish between files and directories, + * until access time. + */ +static const struct file_operations proc_sys_file_operations = { + .read = proc_sys_read, + .write = proc_sys_write, + .readdir = proc_sys_readdir, +}; + +static struct inode_operations proc_sys_inode_operations = { + .lookup = proc_sys_lookup, + .permission = proc_sys_permission, + .setattr = proc_sys_setattr, +}; + +static int proc_sys_revalidate(struct dentry *dentry, struct nameidata *nd) +{ + struct ctl_table_header *head; + struct ctl_table *table; + table = do_proc_sys_lookup(dentry->d_parent, &dentry->d_name, &head); + proc_sys_refresh_inode(dentry->d_inode, table); + sysctl_head_finish(head); + return !!table; +} + +static struct dentry_operations proc_sys_dentry_operations = { + .d_revalidate = proc_sys_revalidate, +}; + +static struct proc_dir_entry *proc_sys_root; + +int proc_sys_init(void) +{ + proc_sys_root = proc_mkdir("sys", NULL); + proc_sys_root->proc_iops = &proc_sys_inode_operations; + proc_sys_root->proc_fops = &proc_sys_file_operations; + proc_sys_root->nlink = 0; + return 0; +} diff --git a/fs/proc/root.c b/fs/proc/root.c index 6ae222b509ce..5834a744c2a9 100644 --- a/fs/proc/root.c +++ b/fs/proc/root.c @@ -23,10 +23,6 @@ struct proc_dir_entry *proc_net, *proc_net_stat, *proc_bus, *proc_root_fs, *proc_root_driver; -#ifdef CONFIG_SYSCTL -struct proc_dir_entry *proc_sys_root; -#endif - static int proc_get_sb(struct file_system_type *fs_type, int flags, const char *dev_name, void *data, struct vfsmount *mnt) { @@ -71,9 +67,6 @@ void __init proc_root_init(void) #ifdef CONFIG_SYSVIPC proc_mkdir("sysvipc", NULL); #endif -#ifdef CONFIG_SYSCTL - proc_sys_root = proc_mkdir("sys", NULL); -#endif proc_root_fs = proc_mkdir("fs", NULL); proc_root_driver = proc_mkdir("driver", NULL); proc_mkdir("fs/nfsd", NULL); /* somewhere for the nfsd filesystem to be mounted */ @@ -86,6 +79,9 @@ void __init proc_root_init(void) proc_device_tree_init(); #endif proc_bus = proc_mkdir("bus", NULL); +#ifdef CONFIG_SYSCTL + proc_sys_init(); +#endif } static int proc_root_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat |