m misc + most of the gamma-linux-drm stuff

Signed-off-by: Mattias Andrée <maandree@operamail.com>

6 files changed, 249 insertions, 6 deletions

diff --git a/Makefile b/Makefile
index 540b219..0e88e3d 100644
--- a/Makefile
+++ b/Makefile
@@ -66,7 +66,7 @@ LIBS_LD =
 LIBS_C =
 
 # Object files for the library.
-LIBOBJ = libgamma-facade libgamma-method gamma-helper
+LIBOBJ = libgamma-facade libgamma-method libgamma-error gamma-helper
 
 
 # Include configurations from `./configure`.
diff --git a/src/gamma-linux-drm.c b/src/gamma-linux-drm.c
index fa0b517..e5e3482 100644
--- a/src/gamma-linux-drm.c
+++ b/src/gamma-linux-drm.c
@@ -19,13 +19,20 @@
 # error Compiling gamma-linux-drm.c without HAVE_GAMMA_METHOD_LINUX_DRM
 #endif
 
+#define _GNU_SOURCE
+
 #include "gamma-linux-drm.h"
 
 #include "libgamma-error.h"
 
-#include <errno.h>
 #include <limits.h>
+#include <stdlib.h>
+#include <errno.h>
 #include <sys/stat.h>
+#include <fcntl.h>
+#include <grp.h>
+#include <unistd.h>
+#include <stdio.h>
 
 #include <xf86drm.h>
 #include <xf86drmMode.h>
@@ -33,11 +40,34 @@
 #ifndef O_CLOEXEC
 # define O_CLOEXEC  02000000
 #endif
+#ifndef NGROUPS_MAX
+# define NGROUPS_MAX  65536
+#endif
 #ifndef PATH_MAX
 # define PATH_MAX  4096
 #endif
 
 
+
+/**
+ * Graphics card data for the Direct Rendering Manager adjustment method
+ */
+typedef struct libgamma_drm_card_data
+{
+  /**
+   * File descriptor for the connection to the graphics card
+   */
+  int fd;
+  
+  /**
+   * The graphics card's mode resources
+   */
+  drmModeRes* res;
+  
+} libgamma_drm_card_data_t;
+
+
+
 /**
  * Return the capabilities of the adjustment method
  * 
@@ -147,7 +177,110 @@ int libgamma_linux_drm_site_restore(libgamma_site_state_t* restrict this)
  */
 int libgamma_linux_drm_partition_initialise(libgamma_partition_state_t* restrict this,
 					    libgamma_site_state_t* restrict site, size_t partition)
-{
+{ /* FIXME: This function is too large. */
+  int rc = 0;
+  libgamma_drm_card_data_t* data;
+  char pathname[PATH_MAX];
+  
+  /* Check for partition index overflow. */
+  if (partition > INT_MAX)
+    return LIBGAMMA_NO_SUCH_PARTITION;
+  
+  /* Allocate and initialise graphics card data.  */
+  this->data = NULL;
+  data = malloc(sizeof(libgamma_drm_card_data_t));
+  if (data == NULL)
+    return LIBGAMMA_ERRNO_SET;
+  data->fd = -1;
+  data->res = NULL;
+  
+  /* Get the pathname for the graphics card. */
+  snprintf(pathname, sizeof(pathname) / sizeof(char),
+	   DRM_DEV_NAME, DRM_DIR_NAME, (int)partition);
+  
+  /* Acquire access to the graphics card. */
+  data->fd = open(pathname, O_RDWR | O_CLOEXEC);
+  if (data->fd < 0)
+    {
+      if ((errno == ENXIO) || (errno == ENODEV))
+	rc = LIBGAMMA_NO_SUCH_PARTITION;
+      else if (errno == EACCES)
+	{
+	  struct stat attr;
+	  int r;
+	  
+	  r = stat(pathname, &attr);
+	  rc = LIBGAMMA_NO_SUCH_PARTITION;
+
+#define __test(R, W) ((attr.st_mode & (R | W)) == (R | W))
+	  if (r)
+	    rc = errno == EACCES ? LIBGAMMA_NO_SUCH_PARTITION : LIBGAMMA_ERRNO_SET;
+	  else if ((attr.st_uid == geteuid() && __test(S_IRUSR, S_IWUSR)) ||
+		   (attr.st_gid == getegid() && __test(S_IRGRP, S_IWGRP)) ||
+		   __test(S_IROTH, S_IWOTH))
+	    rc = LIBGAMMA_DEVICE_ACCESS_FAILED;
+	  else if (attr.st_gid == 0 /* root group */ || __test(S_IRGRP, S_IWGRP))
+	    rc = LIBGAMMA_DEVICE_RESTRICTED;
+	  else
+	    {
+	      gid_t supplemental_groups[NGROUPS_MAX];
+	      struct group* group;
+	      int i, n;
+	      
+	      n = getgroups(NGROUPS_MAX, supplemental_groups);
+	      if (n < 0)
+		{
+		  rc = LIBGAMMA_ERRNO_SET;
+		  goto fail_data;
+		}
+	      
+	      for (i = 0; i < n; i++)
+		if (supplemental_groups[i] == attr.st_gid)
+		  break;
+	      
+	      if (i != n)
+		{
+		  rc = LIBGAMMA_DEVICE_ACCESS_FAILED;
+		  goto fail_data;
+		}
+	      
+	      rc = LIBGAMMA_DEVICE_REQUIRE_GROUP;
+	      errno = 0;
+	      group = getgrgid(attr.st_gid); /* TODO: Not thread-safe. */
+	      libgamma_group_gid = attr.st_gid;
+	      libgamma_group_name = group != NULL ? group->gr_name : NULL;
+	    }
+#undef __test
+	}
+      else
+	rc = LIBGAMMA_ERRNO_SET;
+      goto fail_data;
+    }
+  
+  /* Acquire mode resources. */
+  data->res = drmModeGetResources(data->fd);
+  if (data->res == NULL)
+    {
+      rc = LIBGAMMA_ACQUIRING_MODE_RESOURCES_FAILED;
+      goto fail_fd;
+    }
+  
+  /* Get the number of CRTC:s that are available in the partition. */
+  if (data->res->count_crtcs < 0)
+    {
+      rc = LIBGAMMA_NEGATIVE_CRTC_COUNT;
+      goto fail_res;
+    }
+  this->crtcs_available = (size_t)(data->res->count_crtcs);
+  return 0;
+  
+ fail_res:
+  drmModeFreeResources(data->res);
+ fail_fd:
+  close(data->fd);
+ fail_data:
+  free(data);
+  return rc;
 }
 
 
@@ -158,6 +291,12 @@ int libgamma_linux_drm_partition_initialise(libgamma_partition_state_t* restrict
  */
 void libgamma_linux_drm_partition_destroy(libgamma_partition_state_t* restrict this)
 {
+  libgamma_drm_card_data_t* data = this->data;
+  if (data->res != NULL)
+    drmModeFreeResources(data->res);
+  if (data->fd >= 0)
+    close(data->fd);
+  free(data);
 }
 
 
@@ -188,6 +327,16 @@ int libgamma_linux_drm_partition_restore(libgamma_partition_state_t* restrict th
 int libgamma_linux_drm_crtc_initialise(libgamma_crtc_state_t* restrict this,
 				       libgamma_partition_state_t* restrict partition, size_t crtc)
 {
+  libgamma_drm_card_data_t* card;
+  uint32_t crtc_id;
+  
+  if (crtc >= partition->crtcs_available)
+    return LIBGAMMA_NO_SUCH_CRTC;
+  
+  card = partition->data;
+  crtc_id = card->res->crtcs[crtc];
+  this->data = (void*)(size_t)crtc_id;
+  return 0;
 }
 
 
@@ -242,6 +391,18 @@ int libgamma_linux_drm_get_crtc_information(libgamma_crtc_information_t* restric
 int libgamma_linux_drm_crtc_get_gamma_ramps(libgamma_crtc_state_t* restrict this,
 					    libgamma_gamma_ramps_t* restrict ramps)
 {
+  libgamma_drm_card_data_t* card = this->partition->data;
+  int r;
+#ifdef DEBUG
+  if ((ramps->red_size != ramps->green_size) ||
+      (ramps->red_size != ramps->blue_size))
+    return LIBGAMMA_MIXED_GAMMA_RAMP_SIZE;
+#endif
+  r = drmModeCrtcGetGamma(card->fd, (uint32_t)(this->crtc), (uint32_t)(ramps->red_size),
+			  ramps->red, ramps->green, ramps->blue);
+  if (r < 0)
+    return LIBGAMMA_GAMMA_RAMP_READ_FAILED;
+  return 0;
 }
 
 
diff --git a/src/gamma-linux-drm.h b/src/gamma-linux-drm.h
index 2f757bf..91707ae 100644
--- a/src/gamma-linux-drm.h
+++ b/src/gamma-linux-drm.h
@@ -54,7 +54,7 @@ int libgamma_linux_drm_site_initialise(libgamma_site_state_t* restrict this,
  * 
  * @param  this  The site state
  */
-void libgamma_linux_drm_site_destroy(libgamma_site_state_t* restrict this);
+void libgamma_linux_drm_site_destroy(libgamma_site_state_t* restrict this) __attribute__((const));
 
 /**
  * Restore the gamma ramps all CRTCS with a site to the system settings
@@ -112,7 +112,7 @@ int libgamma_linux_drm_crtc_initialise(libgamma_crtc_state_t* restrict this,
  * 
  * @param  this  The CRTC state
  */
-void libgamma_linux_drm_crtc_destroy(libgamma_crtc_state_t* restrict this);
+void libgamma_linux_drm_crtc_destroy(libgamma_crtc_state_t* restrict this) __attribute__((const));
 
 /**
  * Restore the gamma ramps for a CRTC to the system settings for that CRTC
diff --git a/src/gamma-quartz-cg.c b/src/gamma-quartz-cg.c
index 99d46e1..9bbe0a1 100644
--- a/src/gamma-quartz-cg.c
+++ b/src/gamma-quartz-cg.c
@@ -342,7 +342,8 @@ int libgamma_quartz_cg_crtc_set_gamma_rampsf(libgamma_crtc_state_t* restrict thi
   CGDirectDisplayID crtc_id = crtcs[this->crtc];
   CGError r;
 #ifdef DEBUG
-  if ((ramps.red_size != ramps.green_size) || (ramps.red_size != ramps.blue_size))
+  if ((ramps.red_size != ramps.green_size) ||
+      (ramps.red_size != ramps.blue_size))
     return LIBGAMMA_MIXED_GAMMA_RAMP_SIZE;
 #endif
   r = CGSetDisplayTransferByTable(crtc_id, (uint32_t)(ramps.red_size),
diff --git a/src/libgamma-error.c b/src/libgamma-error.c
new file mode 100644
index 0000000..cd63282
--- /dev/null
+++ b/src/libgamma-error.c
@@ -0,0 +1,35 @@
+/**
+ * libgamma — Display server abstraction layer for gamma ramp adjustments
+ * Copyright © 2014  Mattias Andrée (maandree@member.fsf.org)
+ * 
+ * This library is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ * 
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ * 
+ * You should have received a copy of the GNU General Public License
+ * along with this library.  If not, see <http://www.gnu.org/licenses/>.
+ */
+#include "libgamma-error.h"
+
+
+#include <stddef.h>
+#include <sys/types.h>
+
+
+/**
+ * Group that the user needs to be a member of if `LIBGAMMA_DEVICE_REQUIRE_GROUP` is returned
+ */
+gid_t libgamma_group_gid = 0;
+
+/**
+ * Group that the user needs to be a member of if `LIBGAMMA_DEVICE_REQUIRE_GROUP` is returned,
+ * `NULL` if the name of the group `libgamma_group_gid` cannot be determined
+ */
+const char* libgamma_group_name = NULL;
+
diff --git a/src/libgamma-error.h b/src/libgamma-error.h
index c3c3c2f..5223207 100644
--- a/src/libgamma-error.h
+++ b/src/libgamma-error.h
@@ -22,6 +22,20 @@
 # error libgamma-error.h should not be included directly, include libgamma.h instead
 #endif
 
+#include <sys/types.h>
+
+
+/**
+ * Group that the user needs to be a member of if `LIBGAMMA_DEVICE_REQUIRE_GROUP` is returned
+ */
+extern gid_t libgamma_group_gid;
+
+/**
+ * Group that the user needs to be a member of if `LIBGAMMA_DEVICE_REQUIRE_GROUP` is returned,
+ * `NULL` if the name of the group `libgamma_group_gid` cannot be determined
+ */
+extern const char* libgamma_group_name;
+
 
 /**
  * The selected adjustment method does not exist
@@ -108,6 +122,38 @@
  */
 #define LIBGAMMA_LIST_CRTCS_FAILED  (-16)
 
+/**
+ * Failed to acquire mode resources from the adjustment method
+ */
+#define LIBGAMMA_ACQUIRING_MODE_RESOURCES_FAILED  (-17)
+
+/**
+ * The adjustment method reported that a negative number of partitions exists in the site
+ */
+#define LIBGAMMA_NEGATIVE_PARTITION_COUNT  (-18)
+
+/**
+ * The adjustment method reported that a negative number of CRTC:s exists in the partition
+ */
+#define LIBGAMMA_NEGATIVE_CRTC_COUNT  (-19)
+
+/**
+ * Device cannot be access becauses of insufficient permissions
+ */
+#define LIBGAMMA_DEVICE_RESTRICTED  (-20)
+
+/**
+ * Device cannot be access, reason unknown
+ */
+#define LIBGAMMA_DEVICE_ACCESS_FAILED  (-21)
+
+/**
+ * Device cannot be access, membership of the `libgamma_group_gid`
+ * (named by `libgamma_group_name` (can be `NULL`, if so `errno` may
+ * have been set to tell why)) is required
+ */
+#define LIBGAMMA_DEVICE_REQUIRE_GROUP  (-22)
+
 
 
 #endif