Modalias.cc

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/*---------------------------------------------------------------------\
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|                           / / \ V /|  _/  _/                         |
|                          / /__ | | | | | |                           |
|                         /_____||_| |_| |_|                           |
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\---------------------------------------------------------------------*/
#include <iostream>

#define ZYPP_BASE_LOGGER_LOGGROUP "MODALIAS"
#include "zypp/base/Logger.h"

#include "zypp/target/modalias/Modalias.h"

#include <cstdlib>
#include <stdio.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <unistd.h>
#include <dirent.h>
#include <fnmatch.h>
#include <cstring>
#include <cerrno>

using std::endl;
using std::string;


namespace zypp
{ 

  namespace target
  { 

    namespace modalias
    { 

/*
 * For each file in the directory PATH other than . and .., call
 * FUNC with the arguments PATH, the file's name, and ARG.
 *
 * If FUNC returns a non-zero return value, stop reading the directory
 * and return that value. Returns -1 if an error occurs.
 */
static int
foreach_file(const char *path, int (*func)(const char *, const char *, void *),
             void *arg)
{
        DIR *dir;
        struct dirent *dirent;
        int ret = 0;

        if (!(dir = opendir(path)))
                return -1;
        while ((dirent = readdir(dir)) != NULL) {

                if (strcmp(dirent->d_name, ".") == 0 ||
                    strcmp(dirent->d_name, "..") == 0)
                        continue;
                if ((ret = func(path, dirent->d_name, arg)) != 0)
                        break;
        }
        if (closedir(dir) != 0)
                return -1;
        return ret;
}

struct modalias_list {
        char *modalias;
        struct modalias_list *next;
};

/*
 * If DIR/FILE/modalias exists, remember this modalias on the linked modalias list
 * passed in in ARG. Never returns an error.
 */
static int
read_modalias(const char *dir, const char *file, void *arg)
{
        char path[PATH_MAX];
        int fd;
        ssize_t len;
        char modalias[PATH_MAX];
        struct modalias_list **list = (struct modalias_list **)arg, *entry;

        snprintf(path, sizeof(path), "%s/%s/modalias", dir, file);
        if ((fd = open(path, O_RDONLY)) == -1)
                return 0;
        len = read(fd, modalias, sizeof(modalias) - 1);
        if (len < 0)
                goto out;
        while (len > 0 && modalias[len - 1] == '\n')
                len--;
        modalias[len] = 0;

        if ((entry = (struct modalias_list *)malloc(sizeof(*entry))) == NULL)
                goto out;
        if ((entry->modalias = strdup(modalias)) == NULL) {
                free(entry);
                goto out;
        }
        entry->next = *list;
        *list = entry;
        XXX << "system modalias: " << entry->modalias << endl;

out:
        (void) close(fd);
        return 0;
}

/*
 * Iterate over all devices on a bus (/sys/bus/BUS/devices/<*>)
 * and remembers all module aliases for those devices on
 * the linked modalias list passed in in ARG.
 */
static int
iterate_bus(const char *dir, const char *file, void *arg)
{
        char path[PATH_MAX];

        snprintf(path, sizeof(path), "%s/%s/devices", dir, file);
        (void) foreach_file(path, read_modalias, arg);

        return 0;
}

/*
 * Iterate over all devices in a class (/sys/class/CLASS/<*>)
 * and remembers all module aliases for those devices on
 * the linked modalias list passed in in ARG.
 */
static int
iterate_class(const char *dir, const char *file, void *arg)
{
        char path[PATH_MAX];

        snprintf(path, sizeof(path), "%s/%s", dir, file);
        (void) foreach_file(path, read_modalias, arg);

        return 0;
}

//
//      CLASS NAME : Modalias::Impl
//
struct Modalias::Impl
{
    struct modalias_list *_modaliases;

    Impl()
        : _modaliases(0)
    {
        const char *dir;
        char path[PATH_MAX];

        dir = getenv("ZYPP_MODALIAS_SYSFS");
        if (!dir)
                dir = "/sys";
        DBG << "Using /sys directory : " << dir << endl;

        snprintf(path, sizeof(path), "%s/bus", dir);
        foreach_file( path, iterate_bus, &_modaliases );

        snprintf(path, sizeof(path), "%s/class", dir);
        foreach_file( path, iterate_class, &_modaliases );
    }

    ~Impl()
    {
        while (_modaliases != NULL) {
            struct modalias_list *l = _modaliases;
            _modaliases = _modaliases->next;
            free(l->modalias);
            free(l);
        }
    }

    bool query( const std::string & cap_r ) const
    { return query( cap_r, Rel::ANY, std::string() ); }

    bool  query( const std::string & cap_r,
               Rel op_r,
               const std::string & val_r ) const
    {

        /*
         * Check if a device on the system matches a modalias PATTERN.
         *
         * Returns NULL if no matching device is found, and the modalias
         * of the first matching device otherwise. (More than one device
         * may match a given pattern.)
         *
         * On a system that has the following device,
         *
         *   pci:v00008086d0000265Asv00008086sd00004556bc0Csc03i00
         *
         * modalias_matches("pci:v00008086d0000265Asv*sd*bc*sc*i*") will
         * return a non-NULL value.
         */

        struct modalias_list *l;
        for (l = _modaliases; l; l = l->next) {
            if ( fnmatch( cap_r.c_str(), l->modalias, 0 ) == 0 )
                return true;
        }
        return false;

#if 0           // once we get a capabilities values, we can compare it ...
            if (value) {
                string lhs (value);
                int cmp = (lhs != rhs) ? ((lhs < rhs) ? -1 : 1) : 0;

                switch ( relation.inSwitch() )
                {
                    case Rel::EQ_e:
                        res = (cmp == 0);
                        break;
                    case Rel::NE_e:
                        res = (cmp != 0);
                        break;
                    case Rel::LT_e:
                        res = (cmp == -1);
                        break;
                    case Rel::LE_e:
                        res = (cmp != 1);
                        break;
                    case Rel::GT_e:
                        res = (cmp == 1);
                        break;
                    case Rel::GE_e:
                        res = (cmp != -1);
                        break;
                    case Rel::ANY_e:
                        res = true;
                        break;
                    case Rel::NONE_e:
                        res = false;
                        break;
                    default:
                        // We shouldn't get here.
                        INT << "Unknown relational opertor '" << relation << "' treated as  'NONE'" << endl;
                        break;
                }
            }
#endif

    }

  public:
    static shared_ptr<Impl> nullimpl()
    {
        static shared_ptr<Impl> _nullimpl( new Impl );
        return _nullimpl;
    }

};  // struct Modalias::Impl


inline std::ostream & operator<<( std::ostream & str, const Modalias::Impl & obj )
{
  return str << "Modalias::Impl";
}

//
//      CLASS NAME : Modalias
//

//
//      METHOD NAME : Modalias::Modalias
//      METHOD TYPE : Ctor
//
Modalias::Modalias()
: _pimpl( Impl::nullimpl() )
{}

//
//      METHOD NAME : Modalias::~Modalias
//      METHOD TYPE : Dtor
//
Modalias::~Modalias()
{}

//
//      METHOD NAME : Modalias::instance
//      METHOD TYPE : Modalias &
//
Modalias & Modalias::instance()
{
  static Modalias _singleton;
  return _singleton;
}

// Foreward to implenemtation

bool Modalias::query( const std::string & cap_r ) const
{ return _pimpl->query( cap_r ); }

bool Modalias::query( const std::string & cap_r,
                 Rel op_r,
                 const std::string & val_r ) const
{ return _pimpl->query( cap_r, op_r, val_r ); }

/******************************************************************
**
**      FUNCTION NAME : operator<<
**      FUNCTION TYPE : std::ostream &
*/
std::ostream & operator<<( std::ostream & str, const Modalias & obj )
{
  return str << *obj._pimpl;
}

    } // namespace modalias
  } // namespace target
} // namespace zypp

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