Learn to take a pre-opened file-descriptor for vector IO.
Instead of teaching the driver to open a FD in multiple ways, it can
rely on management layer to do it on its behalf. For example, this
allows inheriting a preconfigured device fd or a simple socketpair()
setup, without further arguments, privileges or system access by UML.
Signed-off-by: Marc-André Lureau <[email protected]>
---
arch/um/drivers/vector_user.c | 59 +++++++++++++++++++++++++++++++++++
1 file changed, 59 insertions(+)
diff --git a/arch/um/drivers/vector_user.c b/arch/um/drivers/vector_user.c
index 29fae0456ade..45c1550dbb37 100644
--- a/arch/um/drivers/vector_user.c
+++ b/arch/um/drivers/vector_user.c
@@ -29,6 +29,7 @@
#include <netdb.h>
#include <stdlib.h>
#include <os.h>
+#include <limits.h>
#include <um_malloc.h>
#include "vector_user.h"
@@ -42,6 +43,9 @@
#define TRANS_RAW "raw"
#define TRANS_RAW_LEN strlen(TRANS_RAW)
+#define TRANS_FD "fd"
+#define TRANS_FD_LEN strlen(TRANS_FD)
+
#define VNET_HDR_FAIL "could not enable vnet headers on fd %d"
#define TUN_GET_F_FAIL "tapraw: TUNGETFEATURES failed: %s"
#define L2TPV3_BIND_FAIL "l2tpv3_open : could not bind socket err=%i"
@@ -347,6 +351,59 @@ static struct vector_fds *user_init_unix_fds(struct arglist *ifspec, int id)
return NULL;
}
+static int strtofd(const char *nptr)
+{
+ long fd;
+ char *endptr;
+
+ if (nptr == NULL)
+ return -1;
+
+ errno = 0;
+ fd = strtol(nptr, &endptr, 10);
+ if (nptr == endptr ||
+ errno != 0 ||
+ *endptr != '\0' ||
+ fd < 0 ||
+ fd > INT_MAX) {
+ return -1;
+ }
+ return fd;
+}
+
+static struct vector_fds *user_init_fd_fds(struct arglist *ifspec)
+{
+ int fd = -1;
+ char *fdarg = NULL;
+ struct vector_fds *result = NULL;
+
+ fdarg = uml_vector_fetch_arg(ifspec, "fd");
+ fd = strtofd(fdarg);
+ if (fd == -1) {
+ printk(UM_KERN_ERR "fd open: bad or missing fd argument");
+ goto fd_cleanup;
+ }
+
+ result = uml_kmalloc(sizeof(struct vector_fds), UM_GFP_KERNEL);
+ if (result == NULL) {
+ printk(UM_KERN_ERR "fd open: allocation failed");
+ goto fd_cleanup;
+ }
+
+ result->rx_fd = fd;
+ result->tx_fd = fd;
+ result->remote_addr_size = 0;
+ result->remote_addr = NULL;
+ return result;
+
+fd_cleanup:
+ if (fd >= 0)
+ os_close_file(fd);
+ if (result != NULL)
+ kfree(result);
+ return NULL;
+}
+
static struct vector_fds *user_init_raw_fds(struct arglist *ifspec)
{
int rxfd = -1, txfd = -1;
@@ -578,6 +635,8 @@ struct vector_fds *uml_vector_user_open(
return user_init_socket_fds(parsed, ID_L2TPV3);
if (strncmp(transport, TRANS_BESS, TRANS_BESS_LEN) == 0)
return user_init_unix_fds(parsed, ID_BESS);
+ if (strncmp(transport, TRANS_FD, TRANS_FD_LEN) == 0)
+ return user_init_fd_fds(parsed);
return NULL;
}
--
2.26.0.106.g9fadedd637
On 07/04/2020 21:28, Marc-André Lureau wrote:
> Learn to take a pre-opened file-descriptor for vector IO.
>
> Instead of teaching the driver to open a FD in multiple ways, it can
> rely on management layer to do it on its behalf. For example, this
> allows inheriting a preconfigured device fd or a simple socketpair()
> setup, without further arguments, privileges or system access by UML.
>
> Signed-off-by: Marc-André Lureau <[email protected]>
> ---
> arch/um/drivers/vector_user.c | 59 +++++++++++++++++++++++++++++++++++
> 1 file changed, 59 insertions(+)
>
> diff --git a/arch/um/drivers/vector_user.c b/arch/um/drivers/vector_user.c
> index 29fae0456ade..45c1550dbb37 100644
> --- a/arch/um/drivers/vector_user.c
> +++ b/arch/um/drivers/vector_user.c
> @@ -29,6 +29,7 @@
> #include <netdb.h>
> #include <stdlib.h>
> #include <os.h>
> +#include <limits.h>
> #include <um_malloc.h>
> #include "vector_user.h"
>
> @@ -42,6 +43,9 @@
> #define TRANS_RAW "raw"
> #define TRANS_RAW_LEN strlen(TRANS_RAW)
>
> +#define TRANS_FD "fd"
> +#define TRANS_FD_LEN strlen(TRANS_FD)
> +
> #define VNET_HDR_FAIL "could not enable vnet headers on fd %d"
> #define TUN_GET_F_FAIL "tapraw: TUNGETFEATURES failed: %s"
> #define L2TPV3_BIND_FAIL "l2tpv3_open : could not bind socket err=%i"
> @@ -347,6 +351,59 @@ static struct vector_fds *user_init_unix_fds(struct arglist *ifspec, int id)
> return NULL;
> }
>
> +static int strtofd(const char *nptr)
> +{
> + long fd;
> + char *endptr;
> +
> + if (nptr == NULL)
> + return -1;
> +
> + errno = 0;
> + fd = strtol(nptr, &endptr, 10);
> + if (nptr == endptr ||
> + errno != 0 ||
> + *endptr != '\0' ||
> + fd < 0 ||
> + fd > INT_MAX) {
> + return -1;
> + }
> + return fd;
> +}
> +
> +static struct vector_fds *user_init_fd_fds(struct arglist *ifspec)
> +{
> + int fd = -1;
> + char *fdarg = NULL;
> + struct vector_fds *result = NULL;
> +
> + fdarg = uml_vector_fetch_arg(ifspec, "fd");
> + fd = strtofd(fdarg);
> + if (fd == -1) {
> + printk(UM_KERN_ERR "fd open: bad or missing fd argument");
> + goto fd_cleanup;
> + }
> +
> + result = uml_kmalloc(sizeof(struct vector_fds), UM_GFP_KERNEL);
> + if (result == NULL) {
> + printk(UM_KERN_ERR "fd open: allocation failed");
> + goto fd_cleanup;
> + }
> +
> + result->rx_fd = fd;
> + result->tx_fd = fd;
> + result->remote_addr_size = 0;
> + result->remote_addr = NULL;
> + return result;
> +
> +fd_cleanup:
> + if (fd >= 0)
> + os_close_file(fd);
> + if (result != NULL)
> + kfree(result);
> + return NULL;
> +}
> +
> static struct vector_fds *user_init_raw_fds(struct arglist *ifspec)
> {
> int rxfd = -1, txfd = -1;
> @@ -578,6 +635,8 @@ struct vector_fds *uml_vector_user_open(
> return user_init_socket_fds(parsed, ID_L2TPV3);
> if (strncmp(transport, TRANS_BESS, TRANS_BESS_LEN) == 0)
> return user_init_unix_fds(parsed, ID_BESS);
> + if (strncmp(transport, TRANS_FD, TRANS_FD_LEN) == 0)
> + return user_init_fd_fds(parsed);
> return NULL;
> }
>
>
We should also control enable/disable of recv/sendmmsg as an option here.
It can be made generic and be fed into get_transport_options() in
vector_kern.c as an override.
--
Anton R. Ivanov
Cambridgegreys Limited. Registered in England. Company Number 10273661
https://www.cambridgegreys.com/
Hi
On Tue, Apr 7, 2020 at 11:02 PM Anton Ivanov
<[email protected]> wrote:
>
> On 07/04/2020 21:28, Marc-André Lureau wrote:
> > Learn to take a pre-opened file-descriptor for vector IO.
> >
> > Instead of teaching the driver to open a FD in multiple ways, it can
> > rely on management layer to do it on its behalf. For example, this
> > allows inheriting a preconfigured device fd or a simple socketpair()
> > setup, without further arguments, privileges or system access by UML.
> >
> > Signed-off-by: Marc-André Lureau <[email protected]>
> > ---
> > arch/um/drivers/vector_user.c | 59 +++++++++++++++++++++++++++++++++++
> > 1 file changed, 59 insertions(+)
> >
> > diff --git a/arch/um/drivers/vector_user.c b/arch/um/drivers/vector_user.c
> > index 29fae0456ade..45c1550dbb37 100644
> > --- a/arch/um/drivers/vector_user.c
> > +++ b/arch/um/drivers/vector_user.c
> > @@ -29,6 +29,7 @@
> > #include <netdb.h>
> > #include <stdlib.h>
> > #include <os.h>
> > +#include <limits.h>
> > #include <um_malloc.h>
> > #include "vector_user.h"
> >
> > @@ -42,6 +43,9 @@
> > #define TRANS_RAW "raw"
> > #define TRANS_RAW_LEN strlen(TRANS_RAW)
> >
> > +#define TRANS_FD "fd"
> > +#define TRANS_FD_LEN strlen(TRANS_FD)
> > +
> > #define VNET_HDR_FAIL "could not enable vnet headers on fd %d"
> > #define TUN_GET_F_FAIL "tapraw: TUNGETFEATURES failed: %s"
> > #define L2TPV3_BIND_FAIL "l2tpv3_open : could not bind socket err=%i"
> > @@ -347,6 +351,59 @@ static struct vector_fds *user_init_unix_fds(struct arglist *ifspec, int id)
> > return NULL;
> > }
> >
> > +static int strtofd(const char *nptr)
> > +{
> > + long fd;
> > + char *endptr;
> > +
> > + if (nptr == NULL)
> > + return -1;
> > +
> > + errno = 0;
> > + fd = strtol(nptr, &endptr, 10);
> > + if (nptr == endptr ||
> > + errno != 0 ||
> > + *endptr != '\0' ||
> > + fd < 0 ||
> > + fd > INT_MAX) {
> > + return -1;
> > + }
> > + return fd;
> > +}
> > +
> > +static struct vector_fds *user_init_fd_fds(struct arglist *ifspec)
> > +{
> > + int fd = -1;
> > + char *fdarg = NULL;
> > + struct vector_fds *result = NULL;
> > +
> > + fdarg = uml_vector_fetch_arg(ifspec, "fd");
> > + fd = strtofd(fdarg);
> > + if (fd == -1) {
> > + printk(UM_KERN_ERR "fd open: bad or missing fd argument");
> > + goto fd_cleanup;
> > + }
> > +
> > + result = uml_kmalloc(sizeof(struct vector_fds), UM_GFP_KERNEL);
> > + if (result == NULL) {
> > + printk(UM_KERN_ERR "fd open: allocation failed");
> > + goto fd_cleanup;
> > + }
> > +
> > + result->rx_fd = fd;
> > + result->tx_fd = fd;
> > + result->remote_addr_size = 0;
> > + result->remote_addr = NULL;
> > + return result;
> > +
> > +fd_cleanup:
> > + if (fd >= 0)
> > + os_close_file(fd);
> > + if (result != NULL)
> > + kfree(result);
> > + return NULL;
> > +}
> > +
> > static struct vector_fds *user_init_raw_fds(struct arglist *ifspec)
> > {
> > int rxfd = -1, txfd = -1;
> > @@ -578,6 +635,8 @@ struct vector_fds *uml_vector_user_open(
> > return user_init_socket_fds(parsed, ID_L2TPV3);
> > if (strncmp(transport, TRANS_BESS, TRANS_BESS_LEN) == 0)
> > return user_init_unix_fds(parsed, ID_BESS);
> > + if (strncmp(transport, TRANS_FD, TRANS_FD_LEN) == 0)
> > + return user_init_fd_fds(parsed);
> > return NULL;
> > }
> >
> >
>
> We should also control enable/disable of recv/sendmmsg as an option here.
>
> It can be made generic and be fed into get_transport_options() in
> vector_kern.c as an override.
So actually, there seems to be a way to do that already:
vec0:transport=fd,fd=N,vec=0
>
> --
> Anton R. Ivanov
> Cambridgegreys Limited. Registered in England. Company Number 10273661
> https://www.cambridgegreys.com/
>
On 08/04/2020 18:07, Marc-André Lureau wrote:
> Hi
>
> On Tue, Apr 7, 2020 at 11:02 PM Anton Ivanov
> <[email protected]> wrote:
>>
>> On 07/04/2020 21:28, Marc-André Lureau wrote:
>>> Learn to take a pre-opened file-descriptor for vector IO.
>>>
>>> Instead of teaching the driver to open a FD in multiple ways, it can
>>> rely on management layer to do it on its behalf. For example, this
>>> allows inheriting a preconfigured device fd or a simple socketpair()
>>> setup, without further arguments, privileges or system access by UML.
>>>
>>> Signed-off-by: Marc-André Lureau <[email protected]>
>>> ---
>>> arch/um/drivers/vector_user.c | 59 +++++++++++++++++++++++++++++++++++
>>> 1 file changed, 59 insertions(+)
>>>
>>> diff --git a/arch/um/drivers/vector_user.c b/arch/um/drivers/vector_user.c
>>> index 29fae0456ade..45c1550dbb37 100644
>>> --- a/arch/um/drivers/vector_user.c
>>> +++ b/arch/um/drivers/vector_user.c
>>> @@ -29,6 +29,7 @@
>>> #include <netdb.h>
>>> #include <stdlib.h>
>>> #include <os.h>
>>> +#include <limits.h>
>>> #include <um_malloc.h>
>>> #include "vector_user.h"
>>>
>>> @@ -42,6 +43,9 @@
>>> #define TRANS_RAW "raw"
>>> #define TRANS_RAW_LEN strlen(TRANS_RAW)
>>>
>>> +#define TRANS_FD "fd"
>>> +#define TRANS_FD_LEN strlen(TRANS_FD)
>>> +
>>> #define VNET_HDR_FAIL "could not enable vnet headers on fd %d"
>>> #define TUN_GET_F_FAIL "tapraw: TUNGETFEATURES failed: %s"
>>> #define L2TPV3_BIND_FAIL "l2tpv3_open : could not bind socket err=%i"
>>> @@ -347,6 +351,59 @@ static struct vector_fds *user_init_unix_fds(struct arglist *ifspec, int id)
>>> return NULL;
>>> }
>>>
>>> +static int strtofd(const char *nptr)
>>> +{
>>> + long fd;
>>> + char *endptr;
>>> +
>>> + if (nptr == NULL)
>>> + return -1;
>>> +
>>> + errno = 0;
>>> + fd = strtol(nptr, &endptr, 10);
>>> + if (nptr == endptr ||
>>> + errno != 0 ||
>>> + *endptr != '\0' ||
>>> + fd < 0 ||
>>> + fd > INT_MAX) {
>>> + return -1;
>>> + }
>>> + return fd;
>>> +}
>>> +
>>> +static struct vector_fds *user_init_fd_fds(struct arglist *ifspec)
>>> +{
>>> + int fd = -1;
>>> + char *fdarg = NULL;
>>> + struct vector_fds *result = NULL;
>>> +
>>> + fdarg = uml_vector_fetch_arg(ifspec, "fd");
>>> + fd = strtofd(fdarg);
>>> + if (fd == -1) {
>>> + printk(UM_KERN_ERR "fd open: bad or missing fd argument");
>>> + goto fd_cleanup;
>>> + }
>>> +
>>> + result = uml_kmalloc(sizeof(struct vector_fds), UM_GFP_KERNEL);
>>> + if (result == NULL) {
>>> + printk(UM_KERN_ERR "fd open: allocation failed");
>>> + goto fd_cleanup;
>>> + }
>>> +
>>> + result->rx_fd = fd;
>>> + result->tx_fd = fd;
>>> + result->remote_addr_size = 0;
>>> + result->remote_addr = NULL;
>>> + return result;
>>> +
>>> +fd_cleanup:
>>> + if (fd >= 0)
>>> + os_close_file(fd);
>>> + if (result != NULL)
>>> + kfree(result);
>>> + return NULL;
>>> +}
>>> +
>>> static struct vector_fds *user_init_raw_fds(struct arglist *ifspec)
>>> {
>>> int rxfd = -1, txfd = -1;
>>> @@ -578,6 +635,8 @@ struct vector_fds *uml_vector_user_open(
>>> return user_init_socket_fds(parsed, ID_L2TPV3);
>>> if (strncmp(transport, TRANS_BESS, TRANS_BESS_LEN) == 0)
>>> return user_init_unix_fds(parsed, ID_BESS);
>>> + if (strncmp(transport, TRANS_FD, TRANS_FD_LEN) == 0)
>>> + return user_init_fd_fds(parsed);
>>> return NULL;
>>> }
>>>
>>>
>>
>> We should also control enable/disable of recv/sendmmsg as an option here.
>>
>> It can be made generic and be fed into get_transport_options() in
>> vector_kern.c as an override.
>
> So actually, there seems to be a way to do that already:
>
> vec0:transport=fd,fd=N,vec=0
I have forgotten about it (it's been a while since I wrote the drivers).
I will update the docs.
In that case the patch looks good to go, I will ack it shortly.
>
>>
>> --
>> Anton R. Ivanov
>> Cambridgegreys Limited. Registered in England. Company Number 10273661
>> https://www.cambridgegreys.com/
>>
>
>
--
Anton R. Ivanov
Cambridgegreys Limited. Registered in England. Company Number 10273661
https://www.cambridgegreys.com/
On 07/04/2020 21:28, Marc-André Lureau wrote:
> Learn to take a pre-opened file-descriptor for vector IO.
>
> Instead of teaching the driver to open a FD in multiple ways, it can
> rely on management layer to do it on its behalf. For example, this
> allows inheriting a preconfigured device fd or a simple socketpair()
> setup, without further arguments, privileges or system access by UML.
>
> Signed-off-by: Marc-André Lureau <[email protected]>
> ---
> arch/um/drivers/vector_user.c | 59 +++++++++++++++++++++++++++++++++++
> 1 file changed, 59 insertions(+)
>
> diff --git a/arch/um/drivers/vector_user.c b/arch/um/drivers/vector_user.c
> index 29fae0456ade..45c1550dbb37 100644
> --- a/arch/um/drivers/vector_user.c
> +++ b/arch/um/drivers/vector_user.c
> @@ -29,6 +29,7 @@
> #include <netdb.h>
> #include <stdlib.h>
> #include <os.h>
> +#include <limits.h>
> #include <um_malloc.h>
> #include "vector_user.h"
>
> @@ -42,6 +43,9 @@
> #define TRANS_RAW "raw"
> #define TRANS_RAW_LEN strlen(TRANS_RAW)
>
> +#define TRANS_FD "fd"
> +#define TRANS_FD_LEN strlen(TRANS_FD)
> +
> #define VNET_HDR_FAIL "could not enable vnet headers on fd %d"
> #define TUN_GET_F_FAIL "tapraw: TUNGETFEATURES failed: %s"
> #define L2TPV3_BIND_FAIL "l2tpv3_open : could not bind socket err=%i"
> @@ -347,6 +351,59 @@ static struct vector_fds *user_init_unix_fds(struct arglist *ifspec, int id)
> return NULL;
> }
>
> +static int strtofd(const char *nptr)
> +{
> + long fd;
> + char *endptr;
> +
> + if (nptr == NULL)
> + return -1;
> +
> + errno = 0;
> + fd = strtol(nptr, &endptr, 10);
> + if (nptr == endptr ||
> + errno != 0 ||
> + *endptr != '\0' ||
> + fd < 0 ||
> + fd > INT_MAX) {
> + return -1;
> + }
> + return fd;
> +}
> +
> +static struct vector_fds *user_init_fd_fds(struct arglist *ifspec)
> +{
> + int fd = -1;
> + char *fdarg = NULL;
> + struct vector_fds *result = NULL;
> +
> + fdarg = uml_vector_fetch_arg(ifspec, "fd");
> + fd = strtofd(fdarg);
> + if (fd == -1) {
> + printk(UM_KERN_ERR "fd open: bad or missing fd argument");
> + goto fd_cleanup;
> + }
> +
> + result = uml_kmalloc(sizeof(struct vector_fds), UM_GFP_KERNEL);
> + if (result == NULL) {
> + printk(UM_KERN_ERR "fd open: allocation failed");
> + goto fd_cleanup;
> + }
> +
> + result->rx_fd = fd;
> + result->tx_fd = fd;
> + result->remote_addr_size = 0;
> + result->remote_addr = NULL;
> + return result;
> +
> +fd_cleanup:
> + if (fd >= 0)
> + os_close_file(fd);
> + if (result != NULL)
> + kfree(result);
> + return NULL;
> +}
> +
> static struct vector_fds *user_init_raw_fds(struct arglist *ifspec)
> {
> int rxfd = -1, txfd = -1;
> @@ -578,6 +635,8 @@ struct vector_fds *uml_vector_user_open(
> return user_init_socket_fds(parsed, ID_L2TPV3);
> if (strncmp(transport, TRANS_BESS, TRANS_BESS_LEN) == 0)
> return user_init_unix_fds(parsed, ID_BESS);
> + if (strncmp(transport, TRANS_FD, TRANS_FD_LEN) == 0)
> + return user_init_fd_fds(parsed);
> return NULL;
> }
>
Acked-By: Anton Ivanov <[email protected]>
--
Anton R. Ivanov
Cambridgegreys Limited. Registered in England. Company Number 10273661
https://www.cambridgegreys.com/