[libvirt] [PATCH v2 09/15] qemu_firmware: Introduce qemuFirmwareFetchConfigs

[Michal Privoznik]

On 3/7/19 12:55 PM, Daniel P. Berrangé wrote:
> On Thu, Mar 07, 2019 at 10:29:19AM +0100, Michal Privoznik wrote:
>> Implementation for yet another part of firmware description
>> specification. This one covers selecting which files to parse.
>>
>> There are three locations from which description files can be
>> loaded. In order of preference, from most generic to most
>> specific these are:
>>
>>    /usr/share/qemu/firmware
>>    /etc/qemu/firmware
>>    $XDG_CONFIG_HOME/qemu/firmware
>>
>> If a file is found in two or more locations then the most specific
>> one is used. Moreover, if file is empty then it means it is
>> overriding some generic description and disabling it.
>>
>> Again, this is described in more details and with nice examples
>> in firmware.json specification (qemu commit 3a0adfc9bf).
>>
>> Signed-off-by: Michal Privoznik <mprivozn at redhat.com>
>> ---
>>   src/qemu/qemu_firmware.c | 134 +++++++++++++++++++++++++++++++++++++++
>>   src/qemu/qemu_firmware.h |   3 +
>>   2 files changed, 137 insertions(+)
>>
>> diff --git a/src/qemu/qemu_firmware.c b/src/qemu/qemu_firmware.c
>> index 8f718ee2a6..a818f60c91 100644
>> --- a/src/qemu/qemu_firmware.c
>> +++ b/src/qemu/qemu_firmware.c
>> @@ -21,9 +21,11 @@
>>   #include <config.h>
>>   
>>   #include "qemu_firmware.h"
>> +#include "configmake.h"
>>   #include "qemu_capabilities.h"
>>   #include "virarch.h"
>>   #include "virfile.h"
>> +#include "virhash.h"
>>   #include "virjson.h"
>>   #include "virlog.h"
>>   #include "virstring.h"
>> @@ -899,3 +901,135 @@ qemuFirmwareFormat(qemuFirmwarePtr fw)
>>   
>>       return virJSONValueToString(doc, true);
>>   }
>> +
>> +
>> +static int
>> +qemuFirmwareBuildFileList(virHashTablePtr files, const char *dir)
>> +{
>> +    DIR *dirp;
>> +    struct dirent *ent = NULL;
>> +    int rc;
>> +    int ret = -1;
>> +
>> +    if ((rc = virDirOpenIfExists(&dirp, dir)) < 0)
>> +        return -1;
>> +
>> +    if (rc == 0)
>> +        return 0;
>> +
>> +    while ((rc = virDirRead(dirp, &ent, dir)) > 0) {
>> +        VIR_AUTOFREE(char *) filename = NULL;
>> +        VIR_AUTOFREE(char *) path = NULL;
>> +
>> +        if (ent->d_type != DT_REG && ent->d_type != DT_LNK)
>> +            continue;
>> +
>> +        if (STRPREFIX(ent->d_name, "."))
>> +            continue;
>> +
>> +        if (VIR_STRDUP(filename, ent->d_name) < 0)
>> +            goto cleanup;
>> +
>> +        if (virAsprintf(&path, "%s/%s", dir, filename) < 0)
>> +            goto cleanup;
>> +
>> +        if (virHashUpdateEntry(files, filename, path) < 0)
>> +            goto cleanup;
>> +
>> +        path = NULL;
>> +    }
>> +
>> +    if (rc < 0)
>> +        goto cleanup;
>> +
>> +    ret = 0;
>> + cleanup:
>> +    virDirClose(&dirp);
>> +    return ret;
>> +}
>> +
>> +static int
>> +qemuFirmwareFilesSorter(const virHashKeyValuePair *a,
>> +                        const virHashKeyValuePair *b)
>> +{
>> +    return strcmp(a->key, b->key);
>> +}
>> +
>> +#define QEMU_FIRMWARE_SYSTEM_LOCATION PREFIX "/share/qemu/firmware"
>> +#define QEMU_FIRMWARE_ETC_LOCATION SYSCONFDIR "/qemu/firmware"
>> +
>> +int
>> +qemuFirmwareFetchConfigs(char ***firmwares)
>> +{
>> +    VIR_AUTOPTR(virHashTable) files = NULL;
>> +    VIR_AUTOFREE(char *) homeConfig = NULL;
>> +    VIR_AUTOFREE(char *) xdgConfig = NULL;
>> +    VIR_AUTOFREE(virHashKeyValuePairPtr) pairs = NULL;
>> +    virHashKeyValuePairPtr tmp = NULL;
>> +
>> +    *firmwares = NULL;
>> +
>> +    if (VIR_STRDUP(xdgConfig, virGetEnvBlockSUID("XDG_CONFIG_HOME")) < 0)
>> +        return -1;
>> +
>> +    if (!xdgConfig) {
>> +        VIR_AUTOFREE(char *) home = virGetUserDirectory();
>> +
>> +        if (!home)
>> +            return -1;
>> +
>> +        if (virAsprintf(&xdgConfig, "%s/.config", home) < 0)
>> +            return -1;
>> +    }
>> +
>> +    if (virAsprintf(&homeConfig, "%s/qemu/firmware", xdgConfig) < 0)
>> +        return -1;
>> +
>> +    if (!(files = virHashCreate(10, virHashValueFree)))
>> +        return -1;
>> +
>> +    if (qemuFirmwareBuildFileList(files, QEMU_FIRMWARE_SYSTEM_LOCATION) < 0)
>> +        return -1;
>> +
>> +    if (qemuFirmwareBuildFileList(files, QEMU_FIRMWARE_ETC_LOCATION) < 0)
>> +        return -1;
>> +
>> +    if (qemuFirmwareBuildFileList(files, homeConfig) < 0)
>> +        return -1;
> 
> I wonder if it really makes sense to read /root/ for this. Normally we would
> only look at the home config for unprivileged daemon, eg we don't look in
> /root for finding PKI x509 certs IIRC.

Fair enough. Root is able to put configs into /etc/qemu/firmware 
anyways. Will fix this locally for now.

Michal