| Message ID | 20230921143622.72387-1-fevalle@ipt.br (mailing list archive) |
|---|---|
| State | Changes Requested, archived |
| Headers | show |
| Series | [v4] platform/x86: thinkpad_acpi: sysfs interface to auxmac | expand |
On Thu, 21 Sep 2023, Fernando Eckhardt Valle wrote: > Newer Thinkpads have a feature called MAC Address Pass-through. > This patch provides a sysfs interface that userspace can use > to get this auxiliary mac address. > > Signed-off-by: Fernando Eckhardt Valle <fevalle@ipt.br> > --- > Changes in v4: > - strscpy() in all string copies. > Changes in v3: > - Added null terminator to auxmac string when copying auxiliary > mac address value. > Changes in v2: > - Added documentation. > - All handling of the auxmac value is done in the _init function. > --- > .../admin-guide/laptops/thinkpad-acpi.rst | 20 +++++ > drivers/platform/x86/thinkpad_acpi.c | 79 +++++++++++++++++++ > 2 files changed, 99 insertions(+) > > diff --git a/Documentation/admin-guide/laptops/thinkpad-acpi.rst b/Documentation/admin-guide/laptops/thinkpad-acpi.rst > index e27a1c3f6..98d304010 100644 > --- a/Documentation/admin-guide/laptops/thinkpad-acpi.rst > +++ b/Documentation/admin-guide/laptops/thinkpad-acpi.rst > @@ -53,6 +53,7 @@ detailed description): > - Lap mode sensor > - Setting keyboard language > - WWAN Antenna type > + - Auxmac > > A compatibility table by model and feature is maintained on the web > site, http://ibm-acpi.sf.net/. I appreciate any success or failure > @@ -1511,6 +1512,25 @@ Currently 2 antenna types are supported as mentioned below: > The property is read-only. If the platform doesn't have support the sysfs > class is not created. > > +Auxmac > +------ > + > +sysfs: auxmac > + > +Some newer Thinkpads have a feature called MAC Address Pass-through. This > +feature is implemented by the system firmware to provide a system unique MAC, > +that can override a dock or USB ethernet dongle MAC, when connected to a > +network. This property enables user-space to easily determine the MAC address > +if the feature is enabled. > + > +The values of this auxiliary MAC are: > + > + cat /sys/devices/platform/thinkpad_acpi/auxmac > + > +If the feature is disabled, the value will be 'disabled'. > + > +This property is read-only. > + > Adaptive keyboard > ----------------- > > diff --git a/drivers/platform/x86/thinkpad_acpi.c b/drivers/platform/x86/thinkpad_acpi.c > index d70c89d32..f430cc9ed 100644 > --- a/drivers/platform/x86/thinkpad_acpi.c > +++ b/drivers/platform/x86/thinkpad_acpi.c > @@ -10785,6 +10785,80 @@ static struct ibm_struct dprc_driver_data = { > .name = "dprc", > }; > > +/* > + * Auxmac > + * > + * This auxiliary mac address is enabled in the bios through the > + * MAC Address Pass-through feature. In most cases, there are three > + * possibilities: Internal Mac, Second Mac, and disabled. > + * > + */ > + > +#define AUXMAC_LEN 12 > +#define AUXMAC_START 9 > +#define AUXMAC_STRLEN 22 > +#define AUXMAC_BEGIN_MARKER 8 > +#define AUXMAC_END_MARKER 21 > + > +static char auxmac[AUXMAC_LEN + 1]; > + > +static int auxmac_init(struct ibm_init_struct *iibm) > +{ > + acpi_status status; > + struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL }; > + union acpi_object *obj; > + > + status = acpi_evaluate_object(NULL, "\\MACA", NULL, &buffer); > + > + if (ACPI_FAILURE(status)) > + return -ENODEV; > + > + obj = buffer.pointer; > + > + if (obj->type != ACPI_TYPE_STRING || obj->string.length != AUXMAC_STRLEN) { > + pr_info("Invalid buffer for MAC address pass-through.\n"); > + strscpy(auxmac, "unavailable", AUXMAC_LEN); > + goto auxmacinvalid; > + } > + > + if (obj->string.pointer[AUXMAC_BEGIN_MARKER] != '#' || > + obj->string.pointer[AUXMAC_END_MARKER] != '#') { > + pr_info("Invalid header for MAC address pass-through.\n"); > + strscpy(auxmac, "unavailable", AUXMAC_LEN); > + goto auxmacinvalid; > + } > + > + if (strncmp(obj->string.pointer + AUXMAC_START, "XXXXXXXXXXXX", AUXMAC_LEN) != 0) > + strscpy(auxmac, obj->string.pointer + AUXMAC_START, AUXMAC_LEN + 1); Okay, I wasn't expecting this change as this relies on the nul termination by strscpy() since the original buffer does not have one but the # character there. But I guess it isn't harmful either. > + else > + strscpy(auxmac, "disabled", AUXMAC_START); AUXMAC_START is an offset ??? It should be AUXMAC_LEN. > + > +auxmacinvalid: > + kfree(obj); > + return 0; I only now realized there are two gotos to auxmacinvalid. Therefore, I'd do this instead: free: kfree(obj); return 0; auxmacinvalid: strscpy(auxmac, "unavailable", AUXMAC_LEN); goto free; I'm sorry about my incorrect suggestion the last time. > +} > + > +static struct ibm_struct auxmac_data = { > + .name = "auxmac", > +}; > + > +static ssize_t auxmac_show(struct device *dev, > + struct device_attribute *attr, > + char *buf) > +{ > + return sysfs_emit(buf, "%s\n", auxmac); > +} > +static DEVICE_ATTR_RO(auxmac); > + > +static struct attribute *auxmac_attributes[] = { > + &dev_attr_auxmac.attr, > + NULL > +}; > + > +static const struct attribute_group auxmac_attr_group = { > + .attrs = auxmac_attributes, > +}; > + > /* --------------------------------------------------------------------- */ > > static struct attribute *tpacpi_driver_attributes[] = { > @@ -10843,6 +10917,7 @@ static const struct attribute_group *tpacpi_groups[] = { > &proxsensor_attr_group, > &kbdlang_attr_group, > &dprc_attr_group, > + &auxmac_attr_group, > NULL, > }; > > @@ -11414,6 +11489,10 @@ static struct ibm_init_struct ibms_init[] __initdata = { > .init = tpacpi_dprc_init, > .data = &dprc_driver_data, > }, > + { > + .init = auxmac_init, > + .data = &auxmac_data, > + }, > }; > > static int __init set_ibm_param(const char *val, const struct kernel_param *kp) >
Hi Ilpo, Thanks for the feedback again! > Okay, I wasn't expecting this change as this relies on the nul termination > by strscpy() since the original buffer does not have one but the # > character there. But I guess it isn't harmful either. Yes, precisely because strscpy() put the 'nul terminator' I thought it would be ok. In the tests I did, everything always worked fine too. > AUXMAC_START is an offset ??? It should be AUXMAC_LEN. I thought that since the string 'disabled' has length 8, then I would use AUXMAC_START which is defined as 9 , because that way strscpy would copy the 8 characters of 'disabled' + the nul terminator. Wouldn't that be correct? Or would it be better to use AUXMAC_LEN which is defined to 12? > I only now realized there are two gotos to auxmacinvalid. Therefore, I'd > do this instead: 2 'goto'... I agree. Fernando
On Fri, 22 Sep 2023, Fernando Eckhardt Valle (FIPT) wrote: > Thanks for the feedback again! > > > Okay, I wasn't expecting this change as this relies on the nul termination > > by strscpy() since the original buffer does not have one but the # > > character there. But I guess it isn't harmful either. > Yes, precisely because strscpy() put the 'nul terminator' I thought it > would be ok. In the tests I did, everything always worked fine too. It was a bit unorthodox way to take advantage of the way strscpy() works but like I said, doesn't look harmful. > > AUXMAC_START is an offset ??? It should be AUXMAC_LEN. > > I thought that since the string 'disabled' has length 8, then I would > use AUXMAC_START which is defined as 9 , because that way strscpy would > copy the 8 characters of 'disabled' + the nul terminator. Wouldn't that > be correct? Or would it be better to use AUXMAC_LEN which is defined to > 12? strscpy() is takes the size of the destination: * @size: Size of destination buffer ...so please use AUXMAC_LEN. In anycase, "disabled" as the source is itself nul-terminated so strscpy() won't copy beyond its length.
Hi, On 9/21/23 16:36, Fernando Eckhardt Valle wrote: > Newer Thinkpads have a feature called MAC Address Pass-through. > This patch provides a sysfs interface that userspace can use > to get this auxiliary mac address. > > Signed-off-by: Fernando Eckhardt Valle <fevalle@ipt.br> > --- > Changes in v4: > - strscpy() in all string copies. > Changes in v3: > - Added null terminator to auxmac string when copying auxiliary > mac address value. > Changes in v2: > - Added documentation. > - All handling of the auxmac value is done in the _init function. > --- > .../admin-guide/laptops/thinkpad-acpi.rst | 20 +++++ > drivers/platform/x86/thinkpad_acpi.c | 79 +++++++++++++++++++ > 2 files changed, 99 insertions(+) > > diff --git a/Documentation/admin-guide/laptops/thinkpad-acpi.rst b/Documentation/admin-guide/laptops/thinkpad-acpi.rst > index e27a1c3f6..98d304010 100644 > --- a/Documentation/admin-guide/laptops/thinkpad-acpi.rst > +++ b/Documentation/admin-guide/laptops/thinkpad-acpi.rst > @@ -53,6 +53,7 @@ detailed description): > - Lap mode sensor > - Setting keyboard language > - WWAN Antenna type > + - Auxmac > > A compatibility table by model and feature is maintained on the web > site, http://ibm-acpi.sf.net/. I appreciate any success or failure > @@ -1511,6 +1512,25 @@ Currently 2 antenna types are supported as mentioned below: > The property is read-only. If the platform doesn't have support the sysfs > class is not created. > > +Auxmac > +------ > + > +sysfs: auxmac > + > +Some newer Thinkpads have a feature called MAC Address Pass-through. This > +feature is implemented by the system firmware to provide a system unique MAC, > +that can override a dock or USB ethernet dongle MAC, when connected to a > +network. This property enables user-space to easily determine the MAC address > +if the feature is enabled. > + > +The values of this auxiliary MAC are: > + > + cat /sys/devices/platform/thinkpad_acpi/auxmac > + > +If the feature is disabled, the value will be 'disabled'. > + > +This property is read-only. > + > Adaptive keyboard > ----------------- > > diff --git a/drivers/platform/x86/thinkpad_acpi.c b/drivers/platform/x86/thinkpad_acpi.c > index d70c89d32..f430cc9ed 100644 > --- a/drivers/platform/x86/thinkpad_acpi.c > +++ b/drivers/platform/x86/thinkpad_acpi.c > @@ -10785,6 +10785,80 @@ static struct ibm_struct dprc_driver_data = { > .name = "dprc", > }; > > +/* > + * Auxmac > + * > + * This auxiliary mac address is enabled in the bios through the > + * MAC Address Pass-through feature. In most cases, there are three > + * possibilities: Internal Mac, Second Mac, and disabled. > + * > + */ > + > +#define AUXMAC_LEN 12 > +#define AUXMAC_START 9 > +#define AUXMAC_STRLEN 22 > +#define AUXMAC_BEGIN_MARKER 8 > +#define AUXMAC_END_MARKER 21 > + > +static char auxmac[AUXMAC_LEN + 1]; > + > +static int auxmac_init(struct ibm_init_struct *iibm) > +{ > + acpi_status status; > + struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL }; > + union acpi_object *obj; > + > + status = acpi_evaluate_object(NULL, "\\MACA", NULL, &buffer); > + > + if (ACPI_FAILURE(status)) > + return -ENODEV; > + > + obj = buffer.pointer; > + > + if (obj->type != ACPI_TYPE_STRING || obj->string.length != AUXMAC_STRLEN) { > + pr_info("Invalid buffer for MAC address pass-through.\n"); > + strscpy(auxmac, "unavailable", AUXMAC_LEN); Please use sizeof(auxmac) as last parameter to strscpy() here. > + goto auxmacinvalid; > + } > + > + if (obj->string.pointer[AUXMAC_BEGIN_MARKER] != '#' || > + obj->string.pointer[AUXMAC_END_MARKER] != '#') { > + pr_info("Invalid header for MAC address pass-through.\n"); > + strscpy(auxmac, "unavailable", AUXMAC_LEN); Please use sizeof(auxmac) as last parameter to strscpy() here. > + goto auxmacinvalid; > + } > + > + if (strncmp(obj->string.pointer + AUXMAC_START, "XXXXXXXXXXXX", AUXMAC_LEN) != 0) > + strscpy(auxmac, obj->string.pointer + AUXMAC_START, AUXMAC_LEN + 1); Please use sizeof(auxmac) as last parameter to strscpy() here. > + else > + strscpy(auxmac, "disabled", AUXMAC_START); Please use sizeof(auxmac) as last parameter to strscpy() here. (using AUXMAC_START here really makes no sense at all) Regards, Hans > + > +auxmacinvalid: > + kfree(obj); > + return 0; > +} > + > +static struct ibm_struct auxmac_data = { > + .name = "auxmac", > +}; > + > +static ssize_t auxmac_show(struct device *dev, > + struct device_attribute *attr, > + char *buf) > +{ > + return sysfs_emit(buf, "%s\n", auxmac); > +} > +static DEVICE_ATTR_RO(auxmac); > + > +static struct attribute *auxmac_attributes[] = { > + &dev_attr_auxmac.attr, > + NULL > +}; > + > +static const struct attribute_group auxmac_attr_group = { > + .attrs = auxmac_attributes, > +}; > + > /* --------------------------------------------------------------------- */ > > static struct attribute *tpacpi_driver_attributes[] = { > @@ -10843,6 +10917,7 @@ static const struct attribute_group *tpacpi_groups[] = { > &proxsensor_attr_group, > &kbdlang_attr_group, > &dprc_attr_group, > + &auxmac_attr_group, > NULL, > }; > > @@ -11414,6 +11489,10 @@ static struct ibm_init_struct ibms_init[] __initdata = { > .init = tpacpi_dprc_init, > .data = &dprc_driver_data, > }, > + { > + .init = auxmac_init, > + .data = &auxmac_data, > + }, > }; > > static int __init set_ibm_param(const char *val, const struct kernel_param *kp)
diff --git a/Documentation/admin-guide/laptops/thinkpad-acpi.rst b/Documentation/admin-guide/laptops/thinkpad-acpi.rst index e27a1c3f6..98d304010 100644 --- a/Documentation/admin-guide/laptops/thinkpad-acpi.rst +++ b/Documentation/admin-guide/laptops/thinkpad-acpi.rst @@ -53,6 +53,7 @@ detailed description): - Lap mode sensor - Setting keyboard language - WWAN Antenna type + - Auxmac A compatibility table by model and feature is maintained on the web site, http://ibm-acpi.sf.net/. I appreciate any success or failure @@ -1511,6 +1512,25 @@ Currently 2 antenna types are supported as mentioned below: The property is read-only. If the platform doesn't have support the sysfs class is not created. +Auxmac +------ + +sysfs: auxmac + +Some newer Thinkpads have a feature called MAC Address Pass-through. This +feature is implemented by the system firmware to provide a system unique MAC, +that can override a dock or USB ethernet dongle MAC, when connected to a +network. This property enables user-space to easily determine the MAC address +if the feature is enabled. + +The values of this auxiliary MAC are: + + cat /sys/devices/platform/thinkpad_acpi/auxmac + +If the feature is disabled, the value will be 'disabled'. + +This property is read-only. + Adaptive keyboard ----------------- diff --git a/drivers/platform/x86/thinkpad_acpi.c b/drivers/platform/x86/thinkpad_acpi.c index d70c89d32..f430cc9ed 100644 --- a/drivers/platform/x86/thinkpad_acpi.c +++ b/drivers/platform/x86/thinkpad_acpi.c @@ -10785,6 +10785,80 @@ static struct ibm_struct dprc_driver_data = { .name = "dprc", }; +/* + * Auxmac + * + * This auxiliary mac address is enabled in the bios through the + * MAC Address Pass-through feature. In most cases, there are three + * possibilities: Internal Mac, Second Mac, and disabled. + * + */ + +#define AUXMAC_LEN 12 +#define AUXMAC_START 9 +#define AUXMAC_STRLEN 22 +#define AUXMAC_BEGIN_MARKER 8 +#define AUXMAC_END_MARKER 21 + +static char auxmac[AUXMAC_LEN + 1]; + +static int auxmac_init(struct ibm_init_struct *iibm) +{ + acpi_status status; + struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL }; + union acpi_object *obj; + + status = acpi_evaluate_object(NULL, "\\MACA", NULL, &buffer); + + if (ACPI_FAILURE(status)) + return -ENODEV; + + obj = buffer.pointer; + + if (obj->type != ACPI_TYPE_STRING || obj->string.length != AUXMAC_STRLEN) { + pr_info("Invalid buffer for MAC address pass-through.\n"); + strscpy(auxmac, "unavailable", AUXMAC_LEN); + goto auxmacinvalid; + } + + if (obj->string.pointer[AUXMAC_BEGIN_MARKER] != '#' || + obj->string.pointer[AUXMAC_END_MARKER] != '#') { + pr_info("Invalid header for MAC address pass-through.\n"); + strscpy(auxmac, "unavailable", AUXMAC_LEN); + goto auxmacinvalid; + } + + if (strncmp(obj->string.pointer + AUXMAC_START, "XXXXXXXXXXXX", AUXMAC_LEN) != 0) + strscpy(auxmac, obj->string.pointer + AUXMAC_START, AUXMAC_LEN + 1); + else + strscpy(auxmac, "disabled", AUXMAC_START); + +auxmacinvalid: + kfree(obj); + return 0; +} + +static struct ibm_struct auxmac_data = { + .name = "auxmac", +}; + +static ssize_t auxmac_show(struct device *dev, + struct device_attribute *attr, + char *buf) +{ + return sysfs_emit(buf, "%s\n", auxmac); +} +static DEVICE_ATTR_RO(auxmac); + +static struct attribute *auxmac_attributes[] = { + &dev_attr_auxmac.attr, + NULL +}; + +static const struct attribute_group auxmac_attr_group = { + .attrs = auxmac_attributes, +}; + /* --------------------------------------------------------------------- */ static struct attribute *tpacpi_driver_attributes[] = { @@ -10843,6 +10917,7 @@ static const struct attribute_group *tpacpi_groups[] = { &proxsensor_attr_group, &kbdlang_attr_group, &dprc_attr_group, + &auxmac_attr_group, NULL, }; @@ -11414,6 +11489,10 @@ static struct ibm_init_struct ibms_init[] __initdata = { .init = tpacpi_dprc_init, .data = &dprc_driver_data, }, + { + .init = auxmac_init, + .data = &auxmac_data, + }, }; static int __init set_ibm_param(const char *val, const struct kernel_param *kp)
Newer Thinkpads have a feature called MAC Address Pass-through. This patch provides a sysfs interface that userspace can use to get this auxiliary mac address. Signed-off-by: Fernando Eckhardt Valle <fevalle@ipt.br> --- Changes in v4: - strscpy() in all string copies. Changes in v3: - Added null terminator to auxmac string when copying auxiliary mac address value. Changes in v2: - Added documentation. - All handling of the auxmac value is done in the _init function. --- .../admin-guide/laptops/thinkpad-acpi.rst | 20 +++++ drivers/platform/x86/thinkpad_acpi.c | 79 +++++++++++++++++++ 2 files changed, 99 insertions(+)