Messages in this thread Patch in this message | | | From | Sam Vilain <> | Subject | [PATCH] namespaces: uts_ns: make information visible via /proc/PID/uts directory | Date | Mon, 22 May 2006 17:24:25 +1200 |
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From: Sam Vilain <sam.vilain@catalyst.net.nz>
Export the UTS information to a per-process directory /proc/PID/uts, that has individual nodes for hostname, ostype, etc - similar to those in /proc/sys/kernel
This duplicates the approach used for /proc/PID/attr, which involves a lot of duplication of similar functions. Much room for maintenance optimisation of both implementations remains. --- Sorry for the duplication of this to the list, stuffed up the stgit command.
After doing this I noticed that the whole way this is done via sysctls in /proc/sys is much, much nicer. I was going there to make /proc/sys/kernel/osname -> /proc/self/uts/sysname (etc), but it seems that symlinks from /proc/sys are not a done thing.
Is there an argument here perhaps for some integration between the way this is done for /proc/sys and /proc/PID/xxx ?
fs/proc/base.c | 236 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 files changed, 236 insertions(+), 0 deletions(-)
diff --git a/fs/proc/base.c b/fs/proc/base.c index 2031913..76f5acb 100644 --- a/fs/proc/base.c +++ b/fs/proc/base.c @@ -73,6 +73,7 @@ #include <linux/cpuset.h> #include <linux/audit.h> #include <linux/poll.h> #include <linux/nsproxy.h> +#include <linux/utsname.h> #include "internal.h" /* NOTE: @@ -179,6 +180,22 @@ #ifdef CONFIG_AUDITSYSCALL #endif PROC_TID_OOM_SCORE, PROC_TID_OOM_ADJUST, +#ifdef CONFIG_UTS_NS + PROC_TID_UTS, + PROC_TGID_UTS, + PROC_TGID_UTS_SYSNAME, + PROC_TGID_UTS_NODENAME, + PROC_TGID_UTS_RELEASE, + PROC_TGID_UTS_VERSION, + PROC_TGID_UTS_MACHINE, + PROC_TGID_UTS_DOMAINNAME, + PROC_TID_UTS_SYSNAME, + PROC_TID_UTS_NODENAME, + PROC_TID_UTS_RELEASE, + PROC_TID_UTS_VERSION, + PROC_TID_UTS_MACHINE, + PROC_TID_UTS_DOMAINNAME, +#endif /* Add new entries before this */ PROC_TID_FD_DIR = 0x8000, /* 0x8000-0xffff */ @@ -238,6 +255,9 @@ #endif #ifdef CONFIG_AUDITSYSCALL E(PROC_TGID_LOGINUID, "loginuid", S_IFREG|S_IWUSR|S_IRUGO), #endif +#ifdef CONFIG_UTS_NS + E(PROC_TGID_UTS, "uts", S_IFDIR|S_IRUGO|S_IXUGO), +#endif {0,0,NULL,0} }; static struct pid_entry tid_base_stuff[] = { @@ -280,6 +300,9 @@ #endif #ifdef CONFIG_AUDITSYSCALL E(PROC_TID_LOGINUID, "loginuid", S_IFREG|S_IWUSR|S_IRUGO), #endif +#ifdef CONFIG_UTS_NS + E(PROC_TID_UTS, "uts", S_IFDIR|S_IRUGO|S_IXUGO), +#endif {0,0,NULL,0} }; @@ -300,6 +323,27 @@ static struct pid_entry tid_attr_stuff[] }; #endif +#ifdef CONFIG_UTS_NS +static struct pid_entry tgid_uts_stuff[] = { + E(PROC_TGID_UTS_SYSNAME, "sysname", S_IFREG|S_IRUGO|S_IWUGO), + E(PROC_TGID_UTS_NODENAME, "nodename", S_IFREG|S_IRUGO|S_IWUGO), + E(PROC_TGID_UTS_RELEASE, "release", S_IFREG|S_IRUGO|S_IWUGO), + E(PROC_TGID_UTS_VERSION, "version", S_IFREG|S_IRUGO|S_IWUGO), + E(PROC_TGID_UTS_MACHINE, "machine", S_IFREG|S_IRUGO|S_IWUGO), + E(PROC_TGID_UTS_DOMAINNAME, "domainname", S_IFREG|S_IRUGO|S_IWUGO), + {0,0,NULL,0} +}; +static struct pid_entry tid_uts_stuff[] = { + E(PROC_TID_UTS_SYSNAME, "sysname", S_IFREG|S_IRUGO|S_IWUGO), + E(PROC_TID_UTS_NODENAME, "nodename", S_IFREG|S_IRUGO|S_IWUGO), + E(PROC_TID_UTS_RELEASE, "release", S_IFREG|S_IRUGO|S_IWUGO), + E(PROC_TID_UTS_VERSION, "version", S_IFREG|S_IRUGO|S_IWUGO), + E(PROC_TID_UTS_MACHINE, "machine", S_IFREG|S_IRUGO|S_IWUGO), + E(PROC_TID_UTS_DOMAINNAME, "domainname", S_IFREG|S_IRUGO|S_IWUGO), + {0,0,NULL,0} +}; +#endif + #undef E static int proc_fd_link(struct inode *inode, struct dentry **dentry, struct vfsmount **mnt) @@ -1608,6 +1652,148 @@ static struct file_operations proc_tgid_ static struct inode_operations proc_tgid_attr_inode_operations; #endif +#ifdef CONFIG_UTS_NS +static ssize_t proc_pid_uts_read(struct file * file, char __user * buf, + size_t count, loff_t *ppos) +{ + struct inode * inode = file->f_dentry->d_inode; + ssize_t length; + loff_t __ppos = *ppos; + struct task_struct *task = get_proc_task(inode); + char __buf[__NEW_UTS_LEN+1]; + char *which; + + length = -ESRCH; + if (!task) + goto out_no_task; + + switch (file->f_dentry->d_name.name[0]) { + case 's': + which = task->nsproxy->uts_ns->name.sysname; + break; + case 'n': + which = task->nsproxy->uts_ns->name.nodename; + break; + case 'r': + which = task->nsproxy->uts_ns->name.release; + break; + case 'v': + which = task->nsproxy->uts_ns->name.version; + break; + case 'm': + which = task->nsproxy->uts_ns->name.machine; + break; + case 'd': + which = task->nsproxy->uts_ns->name.domainname; + break; + default: + printk("procfs: impossible uts part '%s'", + (char*)file->f_dentry->d_name.name); + length = -EINVAL; + goto out; + } + + length = strlen(which); + strcpy(__buf, which); + __buf[length++] = '\n'; + + if (__ppos >= length) + return 0; + if (count > length - __ppos) + count = length - __ppos; + if (copy_to_user(buf, __buf + __ppos, count)) + return -EFAULT; + +out: + put_task_struct(task); +out_no_task: + return length; +} + +static ssize_t proc_pid_uts_write(struct file * file, const char __user * buf, + size_t count, loff_t *ppos) +{ + struct inode * inode = file->f_dentry->d_inode; + ssize_t length; + struct task_struct *task = get_proc_task(inode); + char *which; + char __buf[__NEW_UTS_LEN+1]; + + length = -ESRCH; + if (!task) + goto out_no_task; + if (count > PAGE_SIZE) + count = PAGE_SIZE; + + /* No partial writes. */ + length = -EINVAL; + if (*ppos != 0) + goto out; + if (count > __NEW_UTS_LEN) + goto out; + + length = -EPERM; + if (!capable(CAP_SYS_ADMIN)) + goto out; + + length = -EFAULT; + if (copy_from_user(__buf, buf, count)) + goto out; + + length = -EINVAL; + length = strnlen(__buf, count); + if (count != length) + goto out; + + if (__buf[length-1] == '\n') + length = length - 1; + __buf[length] = '\0'; + + switch (file->f_dentry->d_name.name[0]) { + case 's': + which = task->nsproxy->uts_ns->name.sysname; + break; + case 'n': + which = task->nsproxy->uts_ns->name.nodename; + break; + case 'r': + which = task->nsproxy->uts_ns->name.release; + break; + case 'v': + which = task->nsproxy->uts_ns->name.version; + break; + case 'm': + which = task->nsproxy->uts_ns->name.machine; + break; + case 'd': + which = task->nsproxy->uts_ns->name.domainname; + break; + default: + printk("procfs: impossible uts part '%s'", + (char*)file->f_dentry->d_name.name); + length = -EINVAL; + goto out; + } + + strcpy(which, __buf); + +out: + put_task_struct(task); +out_no_task: + return length; +} + +static struct file_operations proc_pid_uts_operations = { + .read = proc_pid_uts_read, + .write = proc_pid_uts_write, +}; + +static struct file_operations proc_tid_uts_operations; +static struct inode_operations proc_tid_uts_inode_operations; +static struct file_operations proc_tgid_uts_operations; +static struct inode_operations proc_tgid_uts_inode_operations; +#endif + /* SMP-safe */ static struct dentry *proc_pident_lookup(struct inode *dir, struct dentry *dentry, @@ -1760,6 +1946,30 @@ #ifdef CONFIG_SECURITY case PROC_TGID_ATTR_FSCREATE: inode->i_fop = &proc_pid_attr_operations; break; + case PROC_TID_UTS: + inode->i_nlink = 2; + inode->i_op = &proc_tid_uts_inode_operations; + inode->i_fop = &proc_tid_uts_operations; + break; + case PROC_TGID_UTS: + inode->i_nlink = 2; + inode->i_op = &proc_tgid_uts_inode_operations; + inode->i_fop = &proc_tgid_uts_operations; + break; + case PROC_TGID_UTS_SYSNAME: + case PROC_TGID_UTS_NODENAME: + case PROC_TGID_UTS_RELEASE: + case PROC_TGID_UTS_VERSION: + case PROC_TGID_UTS_MACHINE: + case PROC_TGID_UTS_DOMAINNAME: + case PROC_TID_UTS_SYSNAME: + case PROC_TID_UTS_NODENAME: + case PROC_TID_UTS_RELEASE: + case PROC_TID_UTS_VERSION: + case PROC_TID_UTS_MACHINE: + case PROC_TID_UTS_DOMAINNAME: + inode->i_fop = &proc_pid_uts_operations; + break; #endif #ifdef CONFIG_KALLSYMS case PROC_TID_WCHAN: @@ -1889,6 +2099,32 @@ static struct inode_operations proc_tid_ }; #endif +#ifdef CONFIG_UTS_NS +static int proc_tgid_uts_readdir(struct file * filp, + void * dirent, filldir_t filldir) +{ + return proc_pident_readdir(filp,dirent,filldir, + tgid_uts_stuff,ARRAY_SIZE(tgid_uts_stuff)); +} + +static int proc_tid_uts_readdir(struct file * filp, + void * dirent, filldir_t filldir) +{ + return proc_pident_readdir(filp,dirent,filldir, + tid_uts_stuff,ARRAY_SIZE(tid_uts_stuff)); +} + +static struct file_operations proc_tgid_uts_operations = { + .read = generic_read_dir, + .readdir = proc_tgid_uts_readdir, +}; + +static struct file_operations proc_tid_uts_operations = { + .read = generic_read_dir, + .readdir = proc_tid_uts_readdir, +}; +#endif + /* * /proc/self: */ - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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