From 74ff5012af950b792731269e9899ae2462edf7da Mon Sep 17 00:00:00 2001 From: Mattias Andrée Date: Sat, 31 May 2014 07:12:07 +0200 Subject: split out error identification for failure of open from libgamma_linux_drm_partition_initialise MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Signed-off-by: Mattias Andrée --- src/gamma-linux-drm.c | 110 ++++++++++++++++++++++++++------------------------ 1 file changed, 58 insertions(+), 52 deletions(-) diff --git a/src/gamma-linux-drm.c b/src/gamma-linux-drm.c index bf47b6a..36ba442 100644 --- a/src/gamma-linux-drm.c +++ b/src/gamma-linux-drm.c @@ -179,6 +179,63 @@ int libgamma_linux_drm_site_restore(libgamma_site_state_t* restrict this) } +/** + * Figure out why `open` failed for a graphics card + * + * @param pathname The pathname of the error card + * @return The error code to report + */ +static int figure_out_card_open_error(const char* pathname) +{ + if ((errno == ENXIO) || (errno == ENODEV)) + return LIBGAMMA_NO_SUCH_PARTITION; + + if (errno == EACCES) + { + gid_t supplemental_groups[NGROUPS_MAX]; + struct group* group; + int i, n; + struct stat attr; + int r; + + + r = stat(pathname, &attr); + +#define __test(R, W) ((attr.st_mode & (R | W)) == (R | W)) + if (r) + return errno == EACCES ? LIBGAMMA_NO_SUCH_PARTITION : LIBGAMMA_ERRNO_SET; + + if ((attr.st_uid == geteuid() && __test(S_IRUSR, S_IWUSR)) || + (attr.st_gid == getegid() && __test(S_IRGRP, S_IWGRP)) || + __test(S_IROTH, S_IWOTH)) + return LIBGAMMA_DEVICE_ACCESS_FAILED; + + if (attr.st_gid == 0 /* root group */ || __test(S_IRGRP, S_IWGRP)) + return LIBGAMMA_DEVICE_RESTRICTED; + + + n = getgroups(NGROUPS_MAX, supplemental_groups); + if (n < 0) + return LIBGAMMA_ERRNO_SET; + + for (i = 0; i < n; i++) + if (supplemental_groups[i] == attr.st_gid) + break; + + if (i != n) + return LIBGAMMA_DEVICE_ACCESS_FAILED; + + 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; + return LIBGAMMA_DEVICE_REQUIRE_GROUP; +#undef __test + } + + return LIBGAMMA_ERRNO_SET; +} + /** * Initialise an allocated partition state. @@ -218,58 +275,7 @@ int libgamma_linux_drm_partition_initialise(libgamma_partition_state_t* restrict 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; + rc = figure_out_card_open_error(pathname); goto fail_data; } -- cgit v1.2.3-70-g09d2