Patchwork [V3,5/8] virtio-9p: Create support in chroot environment

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Submitter Mohan Kumar M
Date Jan. 18, 2011, 6:25 a.m.
Message ID <1295331954-24130-1-git-send-email-mohan@in.ibm.com>
Download mbox | patch
Permalink /patch/79258/
State New
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Comments

Mohan Kumar M - Jan. 18, 2011, 6:25 a.m.
Add both server & client side interfaces to create regular files in
chroot environment

Signed-off-by: M. Mohan Kumar <mohan@in.ibm.com>
---
 hw/9pfs/virtio-9p-chroot.c |   42 ++++++++++++++++++++++++++++++++++++++++++
 hw/9pfs/virtio-9p-local.c  |   22 ++++++++++++++++++++--
 2 files changed, 62 insertions(+), 2 deletions(-)
Blue Swirl - Jan. 18, 2011, 5:08 p.m.
On Tue, Jan 18, 2011 at 6:25 AM, M. Mohan Kumar <mohan@in.ibm.com> wrote:
> Add both server & client side interfaces to create regular files in
> chroot environment
>
> Signed-off-by: M. Mohan Kumar <mohan@in.ibm.com>
> ---
>  hw/9pfs/virtio-9p-chroot.c |   42 ++++++++++++++++++++++++++++++++++++++++++
>  hw/9pfs/virtio-9p-local.c  |   22 ++++++++++++++++++++--
>  2 files changed, 62 insertions(+), 2 deletions(-)
>
> diff --git a/hw/9pfs/virtio-9p-chroot.c b/hw/9pfs/virtio-9p-chroot.c
> index b599e23..e7f85e2 100644
> --- a/hw/9pfs/virtio-9p-chroot.c
> +++ b/hw/9pfs/virtio-9p-chroot.c
> @@ -193,6 +193,42 @@ static void chroot_do_open(V9fsFileObjectRequest *request, FdInfo *fd_info)
>     }
>  }
>
> +/*
> + * Helper routine to create a file and return the file descriptor and
> + * error status in FdInfo structure.
> + */
> +static void chroot_do_create(V9fsFileObjectRequest *request, FdInfo *fd_info)
> +{
> +    int cur_uid, cur_gid;

uid_t cur_uid;
gid_t cur_gid;

> +
> +    cur_uid = geteuid();
> +    cur_gid = getegid();
> +
> +    fd_info->fi_fd = -1;
> +
> +    if (setfsuid(request->data.uid) < 0) {
> +        fd_info->fi_error = errno;
> +        return;
> +    }
> +    if (setfsgid(request->data.gid) < 0) {
> +        fd_info->fi_error = errno;
> +        goto unset_uid;
> +    }
> +
> +    fd_info->fi_fd = open(request->path.path, request->data.flags,
> +                        request->data.mode);
> +
> +    if (fd_info->fi_fd < 0) {
> +        fd_info->fi_error = errno;
> +    } else {
> +        fd_info->fi_error = 0;
> +    }
> +
> +    setfsgid(cur_gid);
> +unset_uid:
> +    setfsuid(cur_uid);
> +}
> +
>  static int chroot_daemonize(int chroot_sock)
>  {
>     sigset_t sigset;
> @@ -276,6 +312,12 @@ int v9fs_chroot(FsContext *fs_ctx)
>                 error = -2;
>             }
>             break;
> +        case T_CREATE:
> +            chroot_do_create(&request, &fd_info);
> +            if (chroot_sendfd(chroot_sock, &fd_info) <= 0) {
> +                error = -2;
> +            }
> +            break;
>         default:
>             break;
>         }
> diff --git a/hw/9pfs/virtio-9p-local.c b/hw/9pfs/virtio-9p-local.c
> index 2376ec2..7f39b40 100644
> --- a/hw/9pfs/virtio-9p-local.c
> +++ b/hw/9pfs/virtio-9p-local.c
> @@ -52,6 +52,23 @@ static int __open(FsContext *fs_ctx, const char *path, int flags)
>     return fd;
>  }
>
> +static int __create(FsContext *fs_ctx, const char *path, int flags,

Please don't use identifiers starting with underscores.
Mohan Kumar M - Jan. 19, 2011, 11:08 a.m.
Hi Blue Swirl,

Thanks for your review comments. I will address these in my next version of 
patchset.

----
M. Mohan Kumar

On Tuesday 18 January 2011 10:38:21 pm Blue Swirl wrote:
> On Tue, Jan 18, 2011 at 6:25 AM, M. Mohan Kumar <mohan@in.ibm.com> wrote:
> > Add both server & client side interfaces to create regular files in
> > chroot environment
> > 
> > Signed-off-by: M. Mohan Kumar <mohan@in.ibm.com>
> > ---
> >  hw/9pfs/virtio-9p-chroot.c |   42
> > ++++++++++++++++++++++++++++++++++++++++++ hw/9pfs/virtio-9p-local.c  |
> >   22 ++++++++++++++++++++--
> >  2 files changed, 62 insertions(+), 2 deletions(-)
> > 
> > diff --git a/hw/9pfs/virtio-9p-chroot.c b/hw/9pfs/virtio-9p-chroot.c
> > index b599e23..e7f85e2 100644
> > --- a/hw/9pfs/virtio-9p-chroot.c
> > +++ b/hw/9pfs/virtio-9p-chroot.c
> > @@ -193,6 +193,42 @@ static void chroot_do_open(V9fsFileObjectRequest
> > *request, FdInfo *fd_info) }
> >  }
> > 
> > +/*
> > + * Helper routine to create a file and return the file descriptor and
> > + * error status in FdInfo structure.
> > + */
> > +static void chroot_do_create(V9fsFileObjectRequest *request, FdInfo
> > *fd_info) +{
> > +    int cur_uid, cur_gid;
> 
> uid_t cur_uid;
> gid_t cur_gid;
> 
> > +
> > +    cur_uid = geteuid();
> > +    cur_gid = getegid();
> > +
> > +    fd_info->fi_fd = -1;
> > +
> > +    if (setfsuid(request->data.uid) < 0) {
> > +        fd_info->fi_error = errno;
> > +        return;
> > +    }
> > +    if (setfsgid(request->data.gid) < 0) {
> > +        fd_info->fi_error = errno;
> > +        goto unset_uid;
> > +    }
> > +
> > +    fd_info->fi_fd = open(request->path.path, request->data.flags,
> > +                        request->data.mode);
> > +
> > +    if (fd_info->fi_fd < 0) {
> > +        fd_info->fi_error = errno;
> > +    } else {
> > +        fd_info->fi_error = 0;
> > +    }
> > +
> > +    setfsgid(cur_gid);
> > +unset_uid:
> > +    setfsuid(cur_uid);
> > +}
> > +
> >  static int chroot_daemonize(int chroot_sock)
> >  {
> >     sigset_t sigset;
> > @@ -276,6 +312,12 @@ int v9fs_chroot(FsContext *fs_ctx)
> >                 error = -2;
> >             }
> >             break;
> > +        case T_CREATE:
> > +            chroot_do_create(&request, &fd_info);
> > +            if (chroot_sendfd(chroot_sock, &fd_info) <= 0) {
> > +                error = -2;
> > +            }
> > +            break;
> >         default:
> >             break;
> >         }
> > diff --git a/hw/9pfs/virtio-9p-local.c b/hw/9pfs/virtio-9p-local.c
> > index 2376ec2..7f39b40 100644
> > --- a/hw/9pfs/virtio-9p-local.c
> > +++ b/hw/9pfs/virtio-9p-local.c
> > @@ -52,6 +52,23 @@ static int __open(FsContext *fs_ctx, const char *path,
> > int flags) return fd;
> >  }
> > 
> > +static int __create(FsContext *fs_ctx, const char *path, int flags,
> 
> Please don't use identifiers starting with underscores.

Patch

diff --git a/hw/9pfs/virtio-9p-chroot.c b/hw/9pfs/virtio-9p-chroot.c
index b599e23..e7f85e2 100644
--- a/hw/9pfs/virtio-9p-chroot.c
+++ b/hw/9pfs/virtio-9p-chroot.c
@@ -193,6 +193,42 @@  static void chroot_do_open(V9fsFileObjectRequest *request, FdInfo *fd_info)
     }
 }
 
+/*
+ * Helper routine to create a file and return the file descriptor and
+ * error status in FdInfo structure.
+ */
+static void chroot_do_create(V9fsFileObjectRequest *request, FdInfo *fd_info)
+{
+    int cur_uid, cur_gid;
+
+    cur_uid = geteuid();
+    cur_gid = getegid();
+
+    fd_info->fi_fd = -1;
+
+    if (setfsuid(request->data.uid) < 0) {
+        fd_info->fi_error = errno;
+        return;
+    }
+    if (setfsgid(request->data.gid) < 0) {
+        fd_info->fi_error = errno;
+        goto unset_uid;
+    }
+
+    fd_info->fi_fd = open(request->path.path, request->data.flags,
+                        request->data.mode);
+
+    if (fd_info->fi_fd < 0) {
+        fd_info->fi_error = errno;
+    } else {
+        fd_info->fi_error = 0;
+    }
+
+    setfsgid(cur_gid);
+unset_uid:
+    setfsuid(cur_uid);
+}
+
 static int chroot_daemonize(int chroot_sock)
 {
     sigset_t sigset;
@@ -276,6 +312,12 @@  int v9fs_chroot(FsContext *fs_ctx)
                 error = -2;
             }
             break;
+        case T_CREATE:
+            chroot_do_create(&request, &fd_info);
+            if (chroot_sendfd(chroot_sock, &fd_info) <= 0) {
+                error = -2;
+            }
+            break;
         default:
             break;
         }
diff --git a/hw/9pfs/virtio-9p-local.c b/hw/9pfs/virtio-9p-local.c
index 2376ec2..7f39b40 100644
--- a/hw/9pfs/virtio-9p-local.c
+++ b/hw/9pfs/virtio-9p-local.c
@@ -52,6 +52,23 @@  static int __open(FsContext *fs_ctx, const char *path, int flags)
     return fd;
 }
 
+static int __create(FsContext *fs_ctx, const char *path, int flags,
+                    FsCred *credp)
+{
+    V9fsFileObjectRequest request;
+    int fd, error = 0;
+
+    fill_request(&request, path, credp);
+    request.data.flags = flags;
+    request.data.type = T_CREATE;
+    fd = v9fs_request(fs_ctx, &request, &error);
+    if (fd < 0) {
+        errno = error;
+    }
+    qemu_free(request.path.path);
+    return fd;
+}
+
 static int local_lstat(FsContext *fs_ctx, const char *path, struct stat *stbuf)
 {
     int err;
@@ -376,8 +393,7 @@  static int local_open2(FsContext *fs_ctx, const char *path, int flags,
             serrno = errno;
             goto err_end;
         }
-    } else if ((fs_ctx->fs_sm == SM_PASSTHROUGH) ||
-               (fs_ctx->fs_sm == SM_NONE)) {
+    } else if (fs_ctx->fs_sm == SM_NONE) {
         fd = open(rpath(fs_ctx, path), flags, credp->fc_mode);
         if (fd == -1) {
             return fd;
@@ -387,6 +403,8 @@  static int local_open2(FsContext *fs_ctx, const char *path, int flags,
             serrno = errno;
             goto err_end;
         }
+    } else if (fs_ctx->fs_sm == SM_PASSTHROUGH) {
+        fd = __create(fs_ctx, path, flags, credp);
     }
     return fd;