Re: [Qemu-devel] [PATCH -V4 1/7] virtio-9p: Introduces an option to specify the security model.

[Aneesh Kumar K.V]

On Wed, May 26, 2010 at 04:21:40PM -0700, Venkateswararao Jujjuri (JV) wrote:
> The new option is:
> 
> -fsdev fstype,id=myid,path=/share_path/,security_model=[mapped|passthrough]
> -virtfs 
> fstype,path=/share_path/,security_model=[mapped|passthrough],mnt_tag=tag
> 
> In the case of mapped security model, files are created with QEMU user
> credentials and the client-user's credentials are saved in extended 
> attributes.
> Whereas in the case of passthrough security model, files on the
> filesystem are directly created with client-user's credentials.
> 
> Signed-off-by: Venkateswararao Jujjuri <address@hidden>
> ---
>  fsdev/qemu-fsdev.c |   14 +++++++++++++-
>  fsdev/qemu-fsdev.h |    1 +
>  hw/virtio-9p.c     |   22 ++++++++++++++++++----
>  qemu-config.c      |   12 +++++++++---
>  qemu-options.hx    |   15 +++++++++++----
>  vl.c               |   18 +++++++++++++++---
>  6 files changed, 67 insertions(+), 15 deletions(-)
> 
> diff --git a/fsdev/qemu-fsdev.c b/fsdev/qemu-fsdev.c
> index 813e1f7..7d7a153 100644
> --- a/fsdev/qemu-fsdev.c
> +++ b/fsdev/qemu-fsdev.c
> @@ -34,7 +34,7 @@ int qemu_fsdev_add(QemuOpts *opts)
>          return -1;
>      }
>  
> -     for (i = 0; i < ARRAY_SIZE(FsTypes); i++) {
> +    for (i = 0; i < ARRAY_SIZE(FsTypes); i++) {
>          if (strcmp(FsTypes[i].name, qemu_opt_get(opts, "fstype")) == 0) {
>              break;
>          }


Don't do whitespace fixup in the same patch.


> @@ -46,10 +46,22 @@ int qemu_fsdev_add(QemuOpts *opts)
>          return -1;
>      }
>  
> +    if (qemu_opt_get(opts, "path") == NULL) {
> +        fprintf(stderr, "fsdev: No path specified.\n");
> +        return -1;
> +    }
> +


How is this related to new option ? 


> +    if (qemu_opt_get(opts, "security_model") == NULL) {
> +        fprintf(stderr, "fsdev: No security_model specified.\n");
> +        return -1;
> +    }
> +
>      fsle = qemu_malloc(sizeof(*fsle));
>  
>      fsle->fse.fsdev_id = qemu_strdup(qemu_opts_id(opts));
>      fsle->fse.path = qemu_strdup(qemu_opt_get(opts, "path"));
> +    fsle->fse.security_model = qemu_strdup(qemu_opt_get(opts,
> +                "security_model"));
>      fsle->fse.ops = FsTypes[i].ops;
>  
>      QTAILQ_INSERT_TAIL(&fstype_entries, fsle, next);
> diff --git a/fsdev/qemu-fsdev.h b/fsdev/qemu-fsdev.h
> index b50fbe0..6c27881 100644
> --- a/fsdev/qemu-fsdev.h
> +++ b/fsdev/qemu-fsdev.h
> @@ -40,6 +40,7 @@ typedef struct FsTypeTable {
>  typedef struct FsTypeEntry {
>      char *fsdev_id;
>      char *path;
> +    char *security_model;
>      FileOperations *ops;
>  } FsTypeEntry;
>  
> diff --git a/hw/virtio-9p.c b/hw/virtio-9p.c
> index 687abc0..a57562a 100644
> --- a/hw/virtio-9p.c
> +++ b/hw/virtio-9p.c
> @@ -2402,7 +2402,7 @@ VirtIODevice *virtio_9p_init(DeviceState *dev, V9fsConf 
> *conf)
>          /* We don't have a fsdev identified by fsdev_id */
>          fprintf(stderr, "Virtio-9p device couldn't find fsdev "
>                      "with the id %s\n", conf->fsdev_id);
> -        exit(1);
> +        return NULL;
>      }
>  
>      if (!fse->path || !conf->tag) {
> @@ -2410,15 +2410,29 @@ VirtIODevice *virtio_9p_init(DeviceState *dev, 
> V9fsConf *conf)
>          fprintf(stderr, "fsdev with id %s needs path "
>                  "and Virtio-9p device needs mount_tag arguments\n",
>                  conf->fsdev_id);
> -        exit(1);
> +        return NULL;
> +    }
> +
> +    if (!strcmp(fse->security_model, "passthrough")) {
> +        /* Files on the Fileserver set to client user credentials */
> +    } else if (!strcmp(fse->security_model, "mapped")) {
> +        /* Files on the fileserver are set to QEMU credentials.
> +         * Client user credentials are saved in extended attributes.
> +         */


The above two if should be dropped add them when you have something to do in 
the if () { }
section.


> +    } else {
> +        /* user haven't specified a correct security option */
> +        fprintf(stderr, "one of the following must be specified as the"
> +                "security option:\n\t security_model=passthrough \n\t "
> +                "security_model=mapped\n");
> +        return NULL;
>      }

We should only have this



>  
>      if (lstat(fse->path, &stat)) {
>          fprintf(stderr, "share path %s does not exist\n", fse->path);
> -        exit(1);
> +        return NULL;
>      } else if (!S_ISDIR(stat.st_mode)) {
>          fprintf(stderr, "share path %s is not a directory \n", fse->path);
> -        exit(1);
> +        return NULL;
>      }
>  
>      s->ctx.fs_root = qemu_strdup(fse->path);
> diff --git a/qemu-config.c b/qemu-config.c
> index d500885..e1e3aa1 100644
> --- a/qemu-config.c
> +++ b/qemu-config.c
> @@ -160,9 +160,12 @@ QemuOptsList qemu_fsdev_opts = {
>          {
>              .name = "fstype",
>              .type = QEMU_OPT_STRING,
> -        }, {
> +        },{
>              .name = "path",
>              .type = QEMU_OPT_STRING,
> +        },{
> +            .name = "security_model",
> +            .type = QEMU_OPT_STRING,
>          },
>          { /*End of list */ }
>      },
> @@ -178,12 +181,15 @@ QemuOptsList qemu_virtfs_opts = {
>          {
>              .name = "fstype",
>              .type = QEMU_OPT_STRING,
> -        }, {
> +        },{
>              .name = "path",
>              .type = QEMU_OPT_STRING,
> -        }, {
> +        },{
>              .name = "mount_tag",
>              .type = QEMU_OPT_STRING,
> +        },{
> +            .name = "security_model",
> +            .type = QEMU_OPT_STRING,
>          },
>  
>          { /*End of list */ }
> diff --git a/qemu-options.hx b/qemu-options.hx
> index 12f6b51..d557c92 100644
> --- a/qemu-options.hx
> +++ b/qemu-options.hx
> @@ -482,7 +482,7 @@ ETEXI
>  DEFHEADING(File system options:)
>  
>  DEF("fsdev", HAS_ARG, QEMU_OPTION_fsdev,
> -    "-fsdev local,id=id,path=path\n",
> +    "-fsdev local,id=id,path=path,security_model=[mapped|passthrough]\n",
>      QEMU_ARCH_ALL)
>  
>  STEXI
> @@ -498,7 +498,7 @@ The specific Fstype will determine the applicable options.
>  
>  Options to each backend are described below.
>  
> address@hidden -fsdev local ,address@hidden ,address@hidden
> address@hidden -fsdev local ,address@hidden ,address@hidden ,address@hidden
>  
>  Create a file-system-"device" for local-filesystem.
>  
> @@ -506,6 +506,9 @@ Create a file-system-"device" for local-filesystem.
>  
>  @option{path} specifies the path to be exported. @option{path} is required.
>  
> address@hidden specifies the security model to be followed.
> address@hidden is required.
> +
>  @end table
>  ETEXI
>  #endif
> @@ -514,7 +517,7 @@ ETEXI
>  DEFHEADING(Virtual File system pass-through options:)
>  
>  DEF("virtfs", HAS_ARG, QEMU_OPTION_virtfs,
> -    "-virtfs local,path=path,mount_tag=tag\n",
> +    "-virtfs 
> local,path=path,mount_tag=tag,security_model=[mapped|passthrough]\n",
>      QEMU_ARCH_ALL)
>  
>  STEXI
> @@ -530,7 +533,7 @@ The specific Fstype will determine the applicable options.
>  
>  Options to each backend are described below.
>  
> address@hidden -virtfs local ,address@hidden ,address@hidden
> address@hidden -virtfs local ,address@hidden ,address@hidden ,address@hidden
>  
>  Create a Virtual file-system-pass through for local-filesystem.
>  
> @@ -538,6 +541,10 @@ Create a Virtual file-system-pass through for 
> local-filesystem.
>  
>  @option{path} specifies the path to be exported. @option{path} is required.
>  
> address@hidden specifies the security model to be followed.
> address@hidden is required.
> +
> +
>  @option{mount_tag} specifies the tag with which the exported file is mounted.
>  @option{mount_tag} is required.
>  
> diff --git a/vl.c b/vl.c
> index 85bcc84..a341781 100644
> --- a/vl.c
> +++ b/vl.c
> @@ -3109,10 +3109,21 @@ int main(int argc, char **argv, char **envp)
>                      exit(1);
>                  }
>  
> -                len = strlen(",id=,path=");
> +                if (qemu_opt_get(opts, "fstype") == NULL ||
> +                        qemu_opt_get(opts, "mount_tag") == NULL ||
> +                        qemu_opt_get(opts, "path") == NULL ||
> +                        qemu_opt_get(opts, "security_model") == NULL) {
> +                    fprintf(stderr, "Usage: -virtfs 
> fstype,path=/share_path/,"
> +                            "security_model=[mapped|passthrough],"
> +                            "mnt_tag=tag.\n");
> +                    exit(1);
> +                }
> +
> +                len = strlen(",id=,path=,security_model=");
>                  len += strlen(qemu_opt_get(opts, "fstype"));
>                  len += strlen(qemu_opt_get(opts, "mount_tag"));
>                  len += strlen(qemu_opt_get(opts, "path"));
> +                len += strlen(qemu_opt_get(opts, "security_model"));
>                  arg_fsdev = qemu_malloc((len + 1) * sizeof(*arg_fsdev));
>  
>                  if (!arg_fsdev) {
> @@ -3121,10 +3132,11 @@ int main(int argc, char **argv, char **envp)
>                      exit(1);
>                  }
>  
> -                sprintf(arg_fsdev, "%s,id=%s,path=%s",
> +                sprintf(arg_fsdev, "%s,id=%s,path=%s,security_model=%s",
>                                  qemu_opt_get(opts, "fstype"),
>                                  qemu_opt_get(opts, "mount_tag"),
> -                                qemu_opt_get(opts, "path"));
> +                                qemu_opt_get(opts, "path"),
> +                                qemu_opt_get(opts, "security_model"));
>  
>                  len = strlen("virtio-9p-pci,fsdev=,mount_tag=");
>                  len += 2*strlen(qemu_opt_get(opts, "mount_tag"));
> -- 
> 1.6.5.2
> 
>