Merge "liblog: remove client side permissions checking" (ef0b0de7) · Commits · e / os / android_system_core

liblog/pmsg_reader.cpp

+24 −88

Original line number	Diff line number	Diff line
		@@ -62,59 +62,10 @@ static int pmsgAvailable(log_id_t logId) {
		return -EBADF;
		}

		/* Determine the credentials of the caller */
		static bool uid_has_log_permission(uid_t uid) {
		return (uid == AID_SYSTEM) \|\| (uid == AID_LOG) \|\| (uid == AID_ROOT) \|\| (uid == AID_LOGD);
		}

		static uid_t get_best_effective_uid() {
		uid_t euid;
		uid_t uid;
		gid_t gid;
		ssize_t i;
		static uid_t last_uid = (uid_t)-1;

		if (last_uid != (uid_t)-1) {
		return last_uid;
		}
		uid = __android_log_uid();
		if (uid_has_log_permission(uid)) {
		return last_uid = uid;
		}
		euid = geteuid();
		if (uid_has_log_permission(euid)) {
		return last_uid = euid;
		}
		gid = getgid();
		if (uid_has_log_permission(gid)) {
		return last_uid = gid;
		}
		gid = getegid();
		if (uid_has_log_permission(gid)) {
		return last_uid = gid;
		}
		i = getgroups((size_t)0, NULL);
		if (i > 0) {
		gid_t list[i];

		getgroups(i, list);
		while (--i >= 0) {
		if (uid_has_log_permission(list[i])) {
		return last_uid = list[i];
		}
		}
		}
		return last_uid = uid;
		}

		static int pmsgClear(struct android_log_logger* logger __unused,
		struct android_log_transport_context* transp __unused) {
		if (uid_has_log_permission(get_best_effective_uid())) {
		return unlink("/sys/fs/pstore/pmsg-ramoops-0");
		}
		errno = EPERM;
		return -1;
		}

		/*
		* returns the logger version
		@@ -128,14 +79,12 @@ static int pmsgRead(struct android_log_logger_list* logger_list,
		struct android_log_transport_context* transp, struct log_msg* log_msg) {
		ssize_t ret;
		off_t current, next;
		uid_t uid;
		struct __attribute__((__packed__)) {
		android_pmsg_log_header_t p;
		android_log_header_t l;
		uint8_t prio;
		} buf;
		static uint8_t preread_count;
		bool is_system;

		memset(log_msg, 0, sizeof(*log_msg));

		@@ -195,10 +144,7 @@ static int pmsgRead(struct android_log_logger_list* logger_list,
		((logger_list->start.tv_sec != buf.l.realtime.tv_sec) \|\|
		(logger_list->start.tv_nsec <= buf.l.realtime.tv_nsec)))) &&
		(!logger_list->pid \|\| (logger_list->pid == buf.p.pid))) {
		uid = get_best_effective_uid();
		is_system = uid_has_log_permission(uid);
		if (is_system \|\| (uid == buf.p.uid)) {
		char* msg = is_system ? log_msg->entry_v4.msg : log_msg->entry_v3.msg;
		char* msg = log_msg->entry_v4.msg;
		*msg = buf.prio;
		fd = atomic_load(&transp->context.fd);
		if (fd <= 0) {
		@@ -213,20 +159,16 @@ static int pmsgRead(struct android_log_logger_list* logger_list,
		}

		log_msg->entry_v4.len = buf.p.len - sizeof(buf) + sizeof(buf.prio);
		log_msg->entry_v4.hdr_size =
		is_system ? sizeof(log_msg->entry_v4) : sizeof(log_msg->entry_v3);
		log_msg->entry_v4.hdr_size = sizeof(log_msg->entry_v4);
		log_msg->entry_v4.pid = buf.p.pid;
		log_msg->entry_v4.tid = buf.l.tid;
		log_msg->entry_v4.sec = buf.l.realtime.tv_sec;
		log_msg->entry_v4.nsec = buf.l.realtime.tv_nsec;
		log_msg->entry_v4.lid = buf.l.id;
		if (is_system) {
		log_msg->entry_v4.uid = buf.p.uid;
		}

		return ret + sizeof(buf.prio) + log_msg->entry_v4.hdr_size;
		}
		}

		fd = atomic_load(&transp->context.fd);
		if (fd <= 0) {
		@@ -273,13 +215,7 @@ ssize_t __android_log_pmsg_file_read(log_id_t logId, char prio, const char* pref
		struct android_log_transport_context transp;
		struct content {
		struct listnode node;
		union {
		struct logger_entry_v4 entry;
		struct logger_entry_v4 entry_v4;
		struct logger_entry_v3 entry_v3;
		struct logger_entry_v2 entry_v2;
		struct logger_entry entry_v1;
		};
		} * content;
		struct names {
		struct listnode node;