logd: drop libminijail dependency (c65f2ca8) · Commits · e / os / android_system_core

logd/Android.mk

+1 −1

Original line number	Diff line number	Diff line
		@@ -29,7 +29,7 @@ LOCAL_SHARED_LIBRARIES := \
		libcutils \
		libbase \
		libpackagelistparser \
		libminijail
		libcap

		# This is what we want to do:
		# event_logtags = $(shell \

logd/main.cpp

+46 −8

Original line number	Diff line number	Diff line
		@@ -41,12 +41,10 @@
		#include <cutils/sched_policy.h>
		#include <cutils/files.h>
		#include <cutils/sockets.h>
		#include <libminijail.h>
		#include <log/event_tag_map.h>
		#include <packagelistparser/packagelistparser.h>
		#include <private/android_filesystem_config.h>
		#include <private/android_logger.h>
		#include <scoped_minijail.h>
		#include <utils/threads.h>

		#include "CommandListener.h"
		@@ -112,13 +110,53 @@ static int drop_privs() {
		return -1;
		}

		if (prctl(PR_SET_KEEPCAPS, 1) < 0) {
		android::prdebug("failed to set PR_SET_KEEPCAPS");
		return -1;
		}

		std::unique_ptr<struct _cap_struct, int()(void )> caps(cap_init(), cap_free);
		if (cap_clear(caps.get()) < 0) return -1;
		cap_value_t cap_value[] = {
		CAP_SETGID, // must be first for below
		CAP_SYSLOG,
		CAP_AUDIT_CONTROL
		};
		if (cap_set_flag(caps.get(), CAP_PERMITTED,
		arraysize(cap_value), cap_value,
		CAP_SET) < 0) return -1;
		if (cap_set_flag(caps.get(), CAP_EFFECTIVE,
		arraysize(cap_value), cap_value,
		CAP_SET) < 0) return -1;
		if (cap_set_proc(caps.get()) < 0) {
		android::prdebug("failed to set CAP_SETGID, CAP_SYSLOG or CAP_AUDIT_CONTROL (%d)", errno);
		return -1;
		}

		gid_t groups[] = { AID_READPROC };
		ScopedMinijail j(minijail_new());
		minijail_set_supplementary_gids(j.get(), arraysize(groups), groups);
		minijail_change_uid(j.get(), AID_LOGD);
		minijail_change_gid(j.get(), AID_LOGD);
		minijail_use_caps(j.get(), CAP_TO_MASK(CAP_SYSLOG) \| CAP_TO_MASK(CAP_AUDIT_CONTROL));
		minijail_enter(j.get());

		if (setgroups(arraysize(groups), groups) == -1) {
		android::prdebug("failed to set AID_READPROC groups");
		return -1;
		}

		if (setgid(AID_LOGD) != 0) {
		android::prdebug("failed to set AID_LOGD gid");
		return -1;
		}

		if (setuid(AID_LOGD) != 0) {
		android::prdebug("failed to set AID_LOGD uid");
		return -1;
		}

		if (cap_set_flag(caps.get(), CAP_PERMITTED, 1, cap_value, CAP_CLEAR) < 0) return -1;
		if (cap_set_flag(caps.get(), CAP_EFFECTIVE, 1, cap_value, CAP_CLEAR) < 0) return -1;
		if (cap_set_proc(caps.get()) < 0) {
		android::prdebug("failed to clear CAP_SETGID (%d)", errno);
		return -1;
		}

		return 0;
		}