Linux-2.6.12-rc2
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
This commit is contained in:
Linus Torvalds
291
net/core/scm.c
Normal file
291
net/core/scm.c
Normal file
@@ -0,0 +1,291 @@
|
||||
/* scm.c - Socket level control messages processing.
|
||||
*
|
||||
* Author: Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
|
||||
* Alignment and value checking mods by Craig Metz
|
||||
*
|
||||
* This program is free software; you can redistribute it and/or
|
||||
* modify it under the terms of the GNU General Public License
|
||||
* as published by the Free Software Foundation; either version
|
||||
* 2 of the License, or (at your option) any later version.
|
||||
*/
|
||||
|
||||
#include <linux/module.h>
|
||||
#include <linux/signal.h>
|
||||
#include <linux/errno.h>
|
||||
#include <linux/sched.h>
|
||||
#include <linux/mm.h>
|
||||
#include <linux/kernel.h>
|
||||
#include <linux/major.h>
|
||||
#include <linux/stat.h>
|
||||
#include <linux/socket.h>
|
||||
#include <linux/file.h>
|
||||
#include <linux/fcntl.h>
|
||||
#include <linux/net.h>
|
||||
#include <linux/interrupt.h>
|
||||
#include <linux/netdevice.h>
|
||||
#include <linux/security.h>
|
||||
|
||||
#include <asm/system.h>
|
||||
#include <asm/uaccess.h>
|
||||
|
||||
#include <net/protocol.h>
|
||||
#include <linux/skbuff.h>
|
||||
#include <net/sock.h>
|
||||
#include <net/compat.h>
|
||||
#include <net/scm.h>
|
||||
|
||||
|
||||
/*
|
||||
* Only allow a user to send credentials, that they could set with
|
||||
* setu(g)id.
|
||||
*/
|
||||
|
||||
static __inline__ int scm_check_creds(struct ucred *creds)
|
||||
{
|
||||
if ((creds->pid == current->tgid || capable(CAP_SYS_ADMIN)) &&
|
||||
((creds->uid == current->uid || creds->uid == current->euid ||
|
||||
creds->uid == current->suid) || capable(CAP_SETUID)) &&
|
||||
((creds->gid == current->gid || creds->gid == current->egid ||
|
||||
creds->gid == current->sgid) || capable(CAP_SETGID))) {
|
||||
return 0;
|
||||
}
|
||||
return -EPERM;
|
||||
}
|
||||
|
||||
static int scm_fp_copy(struct cmsghdr *cmsg, struct scm_fp_list **fplp)
|
||||
{
|
||||
int *fdp = (int*)CMSG_DATA(cmsg);
|
||||
struct scm_fp_list *fpl = *fplp;
|
||||
struct file **fpp;
|
||||
int i, num;
|
||||
|
||||
num = (cmsg->cmsg_len - CMSG_ALIGN(sizeof(struct cmsghdr)))/sizeof(int);
|
||||
|
||||
if (num <= 0)
|
||||
return 0;
|
||||
|
||||
if (num > SCM_MAX_FD)
|
||||
return -EINVAL;
|
||||
|
||||
if (!fpl)
|
||||
{
|
||||
fpl = kmalloc(sizeof(struct scm_fp_list), GFP_KERNEL);
|
||||
if (!fpl)
|
||||
return -ENOMEM;
|
||||
*fplp = fpl;
|
||||
fpl->count = 0;
|
||||
}
|
||||
fpp = &fpl->fp[fpl->count];
|
||||
|
||||
if (fpl->count + num > SCM_MAX_FD)
|
||||
return -EINVAL;
|
||||
|
||||
/*
|
||||
* Verify the descriptors and increment the usage count.
|
||||
*/
|
||||
|
||||
for (i=0; i< num; i++)
|
||||
{
|
||||
int fd = fdp[i];
|
||||
struct file *file;
|
||||
|
||||
if (fd < 0 || !(file = fget(fd)))
|
||||
return -EBADF;
|
||||
*fpp++ = file;
|
||||
fpl->count++;
|
||||
}
|
||||
return num;
|
||||
}
|
||||
|
||||
void __scm_destroy(struct scm_cookie *scm)
|
||||
{
|
||||
struct scm_fp_list *fpl = scm->fp;
|
||||
int i;
|
||||
|
||||
if (fpl) {
|
||||
scm->fp = NULL;
|
||||
for (i=fpl->count-1; i>=0; i--)
|
||||
fput(fpl->fp[i]);
|
||||
kfree(fpl);
|
||||
}
|
||||
}
|
||||
|
||||
int __scm_send(struct socket *sock, struct msghdr *msg, struct scm_cookie *p)
|
||||
{
|
||||
struct cmsghdr *cmsg;
|
||||
int err;
|
||||
|
||||
for (cmsg = CMSG_FIRSTHDR(msg); cmsg; cmsg = CMSG_NXTHDR(msg, cmsg))
|
||||
{
|
||||
err = -EINVAL;
|
||||
|
||||
/* Verify that cmsg_len is at least sizeof(struct cmsghdr) */
|
||||
/* The first check was omitted in <= 2.2.5. The reasoning was
|
||||
that parser checks cmsg_len in any case, so that
|
||||
additional check would be work duplication.
|
||||
But if cmsg_level is not SOL_SOCKET, we do not check
|
||||
for too short ancillary data object at all! Oops.
|
||||
OK, let's add it...
|
||||
*/
|
||||
if (!CMSG_OK(msg, cmsg))
|
||||
goto error;
|
||||
|
||||
if (cmsg->cmsg_level != SOL_SOCKET)
|
||||
continue;
|
||||
|
||||
switch (cmsg->cmsg_type)
|
||||
{
|
||||
case SCM_RIGHTS:
|
||||
err=scm_fp_copy(cmsg, &p->fp);
|
||||
if (err<0)
|
||||
goto error;
|
||||
break;
|
||||
case SCM_CREDENTIALS:
|
||||
if (cmsg->cmsg_len != CMSG_LEN(sizeof(struct ucred)))
|
||||
goto error;
|
||||
memcpy(&p->creds, CMSG_DATA(cmsg), sizeof(struct ucred));
|
||||
err = scm_check_creds(&p->creds);
|
||||
if (err)
|
||||
goto error;
|
||||
break;
|
||||
default:
|
||||
goto error;
|
||||
}
|
||||
}
|
||||
|
||||
if (p->fp && !p->fp->count)
|
||||
{
|
||||
kfree(p->fp);
|
||||
p->fp = NULL;
|
||||
}
|
||||
return 0;
|
||||
|
||||
error:
|
||||
scm_destroy(p);
|
||||
return err;
|
||||
}
|
||||
|
||||
int put_cmsg(struct msghdr * msg, int level, int type, int len, void *data)
|
||||
{
|
||||
struct cmsghdr __user *cm = (struct cmsghdr __user *)msg->msg_control;
|
||||
struct cmsghdr cmhdr;
|
||||
int cmlen = CMSG_LEN(len);
|
||||
int err;
|
||||
|
||||
if (MSG_CMSG_COMPAT & msg->msg_flags)
|
||||
return put_cmsg_compat(msg, level, type, len, data);
|
||||
|
||||
if (cm==NULL || msg->msg_controllen < sizeof(*cm)) {
|
||||
msg->msg_flags |= MSG_CTRUNC;
|
||||
return 0; /* XXX: return error? check spec. */
|
||||
}
|
||||
if (msg->msg_controllen < cmlen) {
|
||||
msg->msg_flags |= MSG_CTRUNC;
|
||||
cmlen = msg->msg_controllen;
|
||||
}
|
||||
cmhdr.cmsg_level = level;
|
||||
cmhdr.cmsg_type = type;
|
||||
cmhdr.cmsg_len = cmlen;
|
||||
|
||||
err = -EFAULT;
|
||||
if (copy_to_user(cm, &cmhdr, sizeof cmhdr))
|
||||
goto out;
|
||||
if (copy_to_user(CMSG_DATA(cm), data, cmlen - sizeof(struct cmsghdr)))
|
||||
goto out;
|
||||
cmlen = CMSG_SPACE(len);
|
||||
msg->msg_control += cmlen;
|
||||
msg->msg_controllen -= cmlen;
|
||||
err = 0;
|
||||
out:
|
||||
return err;
|
||||
}
|
||||
|
||||
void scm_detach_fds(struct msghdr *msg, struct scm_cookie *scm)
|
||||
{
|
||||
struct cmsghdr __user *cm = (struct cmsghdr __user*)msg->msg_control;
|
||||
|
||||
int fdmax = 0;
|
||||
int fdnum = scm->fp->count;
|
||||
struct file **fp = scm->fp->fp;
|
||||
int __user *cmfptr;
|
||||
int err = 0, i;
|
||||
|
||||
if (MSG_CMSG_COMPAT & msg->msg_flags) {
|
||||
scm_detach_fds_compat(msg, scm);
|
||||
return;
|
||||
}
|
||||
|
||||
if (msg->msg_controllen > sizeof(struct cmsghdr))
|
||||
fdmax = ((msg->msg_controllen - sizeof(struct cmsghdr))
|
||||
/ sizeof(int));
|
||||
|
||||
if (fdnum < fdmax)
|
||||
fdmax = fdnum;
|
||||
|
||||
for (i=0, cmfptr=(int __user *)CMSG_DATA(cm); i<fdmax; i++, cmfptr++)
|
||||
{
|
||||
int new_fd;
|
||||
err = security_file_receive(fp[i]);
|
||||
if (err)
|
||||
break;
|
||||
err = get_unused_fd();
|
||||
if (err < 0)
|
||||
break;
|
||||
new_fd = err;
|
||||
err = put_user(new_fd, cmfptr);
|
||||
if (err) {
|
||||
put_unused_fd(new_fd);
|
||||
break;
|
||||
}
|
||||
/* Bump the usage count and install the file. */
|
||||
get_file(fp[i]);
|
||||
fd_install(new_fd, fp[i]);
|
||||
}
|
||||
|
||||
if (i > 0)
|
||||
{
|
||||
int cmlen = CMSG_LEN(i*sizeof(int));
|
||||
if (!err)
|
||||
err = put_user(SOL_SOCKET, &cm->cmsg_level);
|
||||
if (!err)
|
||||
err = put_user(SCM_RIGHTS, &cm->cmsg_type);
|
||||
if (!err)
|
||||
err = put_user(cmlen, &cm->cmsg_len);
|
||||
if (!err) {
|
||||
cmlen = CMSG_SPACE(i*sizeof(int));
|
||||
msg->msg_control += cmlen;
|
||||
msg->msg_controllen -= cmlen;
|
||||
}
|
||||
}
|
||||
if (i < fdnum || (fdnum && fdmax <= 0))
|
||||
msg->msg_flags |= MSG_CTRUNC;
|
||||
|
||||
/*
|
||||
* All of the files that fit in the message have had their
|
||||
* usage counts incremented, so we just free the list.
|
||||
*/
|
||||
__scm_destroy(scm);
|
||||
}
|
||||
|
||||
struct scm_fp_list *scm_fp_dup(struct scm_fp_list *fpl)
|
||||
{
|
||||
struct scm_fp_list *new_fpl;
|
||||
int i;
|
||||
|
||||
if (!fpl)
|
||||
return NULL;
|
||||
|
||||
new_fpl = kmalloc(sizeof(*fpl), GFP_KERNEL);
|
||||
if (new_fpl) {
|
||||
for (i=fpl->count-1; i>=0; i--)
|
||||
get_file(fpl->fp[i]);
|
||||
memcpy(new_fpl, fpl, sizeof(*fpl));
|
||||
}
|
||||
return new_fpl;
|
||||
}
|
||||
|
||||
EXPORT_SYMBOL(__scm_destroy);
|
||||
EXPORT_SYMBOL(__scm_send);
|
||||
EXPORT_SYMBOL(put_cmsg);
|
||||
EXPORT_SYMBOL(scm_detach_fds);
|
||||
EXPORT_SYMBOL(scm_fp_dup);
|
||||
Reference in New Issue
Block a user