| #include <linux/proc_fs.h> |
| #include <linux/nsproxy.h> |
| #include <linux/ptrace.h> |
| #include <linux/namei.h> |
| #include <linux/file.h> |
| #include <linux/utsname.h> |
| #include <net/net_namespace.h> |
| #include <linux/ipc_namespace.h> |
| #include <linux/pid_namespace.h> |
| #include <linux/user_namespace.h> |
| #include "internal.h" |
| |
| |
| static const struct proc_ns_operations *ns_entries[] = { |
| #ifdef CONFIG_NET_NS |
| &netns_operations, |
| #endif |
| #ifdef CONFIG_UTS_NS |
| &utsns_operations, |
| #endif |
| #ifdef CONFIG_IPC_NS |
| &ipcns_operations, |
| #endif |
| #ifdef CONFIG_PID_NS |
| &pidns_operations, |
| #endif |
| #ifdef CONFIG_USER_NS |
| &userns_operations, |
| #endif |
| &mntns_operations, |
| #ifdef CONFIG_CGROUPS |
| &cgroupns_operations, |
| #endif |
| }; |
| |
| static const char *proc_ns_get_link(struct dentry *dentry, |
| struct inode *inode, |
| struct delayed_call *done) |
| { |
| const struct proc_ns_operations *ns_ops = PROC_I(inode)->ns_ops; |
| struct task_struct *task; |
| struct path ns_path; |
| void *error = ERR_PTR(-EACCES); |
| |
| if (!dentry) |
| return ERR_PTR(-ECHILD); |
| |
| task = get_proc_task(inode); |
| if (!task) |
| return error; |
| |
| if (ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS)) { |
| error = ns_get_path(&ns_path, task, ns_ops); |
| if (!error) |
| nd_jump_link(&ns_path); |
| } |
| put_task_struct(task); |
| return error; |
| } |
| |
| static int proc_ns_readlink(struct dentry *dentry, char __user *buffer, int buflen) |
| { |
| struct inode *inode = d_inode(dentry); |
| const struct proc_ns_operations *ns_ops = PROC_I(inode)->ns_ops; |
| struct task_struct *task; |
| char name[50]; |
| int res = -EACCES; |
| |
| task = get_proc_task(inode); |
| if (!task) |
| return res; |
| |
| if (ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS)) { |
| res = ns_get_name(name, sizeof(name), task, ns_ops); |
| if (res >= 0) |
| res = readlink_copy(buffer, buflen, name); |
| } |
| put_task_struct(task); |
| return res; |
| } |
| |
| static const struct inode_operations proc_ns_link_inode_operations = { |
| .readlink = proc_ns_readlink, |
| .get_link = proc_ns_get_link, |
| .setattr = proc_setattr, |
| }; |
| |
| static int proc_ns_instantiate(struct inode *dir, |
| struct dentry *dentry, struct task_struct *task, const void *ptr) |
| { |
| const struct proc_ns_operations *ns_ops = ptr; |
| struct inode *inode; |
| struct proc_inode *ei; |
| |
| inode = proc_pid_make_inode(dir->i_sb, task, S_IFLNK | S_IRWXUGO); |
| if (!inode) |
| goto out; |
| |
| ei = PROC_I(inode); |
| inode->i_op = &proc_ns_link_inode_operations; |
| ei->ns_ops = ns_ops; |
| |
| d_set_d_op(dentry, &pid_dentry_operations); |
| d_add(dentry, inode); |
| /* Close the race of the process dying before we return the dentry */ |
| if (pid_revalidate(dentry, 0)) |
| return 0; |
| out: |
| return -ENOENT; |
| } |
| |
| static int proc_ns_dir_readdir(struct file *file, struct dir_context *ctx) |
| { |
| struct task_struct *task = get_proc_task(file_inode(file)); |
| const struct proc_ns_operations **entry, **last; |
| |
| if (!task) |
| return -ENOENT; |
| |
| if (!dir_emit_dots(file, ctx)) |
| goto out; |
| if (ctx->pos >= 2 + ARRAY_SIZE(ns_entries)) |
| goto out; |
| entry = ns_entries + (ctx->pos - 2); |
| last = &ns_entries[ARRAY_SIZE(ns_entries) - 1]; |
| while (entry <= last) { |
| const struct proc_ns_operations *ops = *entry; |
| if (!proc_fill_cache(file, ctx, ops->name, strlen(ops->name), |
| proc_ns_instantiate, task, ops)) |
| break; |
| ctx->pos++; |
| entry++; |
| } |
| out: |
| put_task_struct(task); |
| return 0; |
| } |
| |
| const struct file_operations proc_ns_dir_operations = { |
| .read = generic_read_dir, |
| .iterate_shared = proc_ns_dir_readdir, |
| .llseek = generic_file_llseek, |
| }; |
| |
| static struct dentry *proc_ns_dir_lookup(struct inode *dir, |
| struct dentry *dentry, unsigned int flags) |
| { |
| int error; |
| struct task_struct *task = get_proc_task(dir); |
| const struct proc_ns_operations **entry, **last; |
| unsigned int len = dentry->d_name.len; |
| |
| error = -ENOENT; |
| |
| if (!task) |
| goto out_no_task; |
| |
| last = &ns_entries[ARRAY_SIZE(ns_entries)]; |
| for (entry = ns_entries; entry < last; entry++) { |
| if (strlen((*entry)->name) != len) |
| continue; |
| if (!memcmp(dentry->d_name.name, (*entry)->name, len)) |
| break; |
| } |
| if (entry == last) |
| goto out; |
| |
| error = proc_ns_instantiate(dir, dentry, task, *entry); |
| out: |
| put_task_struct(task); |
| out_no_task: |
| return ERR_PTR(error); |
| } |
| |
| const struct inode_operations proc_ns_dir_inode_operations = { |
| .lookup = proc_ns_dir_lookup, |
| .getattr = pid_getattr, |
| .setattr = proc_setattr, |
| }; |