Include meminfo-writer

It is common for dom0 and VM, so keep in one place for both of them.

Makefile

@@ -16,10 +16,12 @@ rpms:
 	rpmbuild --define "_rpmdir rpm/" --define "_builddir ." -bb rpm_spec/qubes-utils.spec
 all: 
 	$(MAKE) -C qrexec-lib all
+	$(MAKE) -C qmemman all
 
 install:
 	$(MAKE) -C udev install
 	$(MAKE) -C qrexec-lib install
+	$(MAKE) -C qmemman install
 
 clean:
 	$(MAKE) -C qrexec-lib clean

qmemman/Makefile

@@ -0,0 +1,11 @@
+CC=gcc
+CFLAGS=-Wall -g -O3
+all:	meminfo-writer
+meminfo-writer: meminfo-writer.o
+	$(CC) -g -o meminfo-writer meminfo-writer.o -lxenstore
+install:
+	install -D meminfo-writer $(DESTDIR)/usr/sbin/meminfo-writer
+	install -d $(DESTDIR)/usr/lib/systemd/system/
+	install qubes-meminfo-writer*service $(DESTDIR)/usr/lib/systemd/system/
+clean:
+	rm -f meminfo-writer xenstore-watch *.o

qmemman/meminfo-writer.c

@@ -0,0 +1,176 @@
+#include <fcntl.h>
+#include <unistd.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <xs.h>
+#include <syslog.h>
+#include <string.h>
+#include <signal.h>
+
+unsigned long prev_used_mem;
+int used_mem_change_threshold;
+int delay;
+int usr1_received;
+
+char *parse(char *buf)
+{
+	char *ptr = buf;
+	char name[256];
+	static char outbuf[4096];
+	int val;
+	int len;
+	int MemTotal = 0, MemFree = 0, Buffers = 0, Cached = 0, SwapTotal =
+	    0, SwapFree = 0;
+	unsigned long long key;
+	long used_mem, used_mem_diff;
+	int nitems = 0;
+
+	while (nitems != 6) {
+		sscanf(ptr, "%s %d kB\n%n", name, &val, &len);
+		key = *(unsigned long long *) ptr;
+		if (key == *(unsigned long long *) "MemTotal:") {
+			MemTotal = val;
+			nitems++;
+		} else if (key == *(unsigned long long *) "MemFree:") {
+			MemFree = val;
+			nitems++;
+		} else if (key == *(unsigned long long *) "Buffers:") {
+			Buffers = val;
+			nitems++;
+		} else if (key == *(unsigned long long *) "Cached:  ") {
+			Cached = val;
+			nitems++;
+		} else if (key == *(unsigned long long *) "SwapTotal:") {
+			SwapTotal = val;
+			nitems++;
+		} else if (key == *(unsigned long long *) "SwapFree:") {
+			SwapFree = val;
+			nitems++;
+		}
+
+		ptr += len;
+	}
+
+	used_mem =
+	    MemTotal - Buffers - Cached - MemFree + SwapTotal - SwapFree;
+	if (used_mem < 0)
+		return NULL;
+
+	used_mem_diff = used_mem - prev_used_mem;
+	if (used_mem_diff < 0)
+		used_mem_diff = -used_mem_diff;
+	if (used_mem_diff > used_mem_change_threshold
+	    || (used_mem > prev_used_mem && used_mem * 13 / 10 > MemTotal
+		&& used_mem_diff > used_mem_change_threshold/2)) {
+		prev_used_mem = used_mem;
+		sprintf(outbuf,
+			"MemTotal: %d kB\nMemFree: %d kB\nBuffers: %d kB\nCached: %d kB\n"
+			"SwapTotal: %d kB\nSwapFree: %d kB\n", MemTotal,
+			MemFree, Buffers, Cached, SwapTotal, SwapFree);
+		return outbuf;
+	}
+	return NULL;
+}
+
+void usage()
+{
+	fprintf(stderr,
+		"usage: meminfo_writer threshold_in_kb delay_in_us [pidfile]\n");
+	fprintf(stderr, "  When pidfile set, meminfo-writer will:\n");
+    fprintf(stderr, "   - fork into background\n");
+	fprintf(stderr, "   - wait for SIGURS1 (in background) before starting main work\n");
+	exit(1);
+}
+
+void send_to_qmemman(struct xs_handle *xs, char *data)
+{
+	if (!xs_write(xs, XBT_NULL, "memory/meminfo", data, strlen(data))) {
+		syslog(LOG_DAEMON | LOG_ERR, "error writing xenstore ?");
+		exit(1);
+	}
+}
+
+void usr1_handler(int sig) {
+	usr1_received = 1;
+}
+
+int main(int argc, char **argv)
+{
+	char buf[4096];
+	int n;
+	char *meminfo_data;
+	int fd;
+	struct xs_handle *xs;
+
+	if (argc != 3 && argc != 4)
+		usage();
+	used_mem_change_threshold = atoi(argv[1]);
+	delay = atoi(argv[2]);
+	if (!used_mem_change_threshold || !delay)
+		usage();
+
+	if (argc == 4) {
+		pid_t pid;
+		sigset_t mask, oldmask;
+
+		switch (pid = fork()) {
+			case -1:
+				perror("fork");
+				exit(1);
+			case 0:
+				sigemptyset (&mask); 
+				sigaddset (&mask, SIGUSR1);
+				/* Wait for a signal to arrive. */
+				sigprocmask (SIG_BLOCK, &mask, &oldmask);
+				usr1_received = 0;
+				signal(SIGUSR1, usr1_handler);
+				while (!usr1_received)
+					  sigsuspend (&oldmask);
+				sigprocmask (SIG_UNBLOCK, &mask, NULL);
+				break;
+			default:
+				fd = open(argv[3], O_CREAT | O_TRUNC | O_WRONLY, 0666);
+				if (fd < 0) {
+					perror("open pidfile");
+					exit(1);
+				}
+				n = sprintf(buf, "%d\n", pid);
+				if (write(fd, buf, n) != n) {
+					perror("write pid");
+					exit(1);
+				}
+				close(fd);
+				exit(0);
+		}
+	}
+
+	fd = open("/proc/meminfo", O_RDONLY);
+	if (fd < 0) {
+		perror("open meminfo");
+		exit(1);
+	}
+	xs = xs_domain_open();
+	if (!xs) {
+		perror("xs_domain_open");
+		exit(1);
+	}
+	if (argc == 3) {
+		/* if not waiting for signal, fork after first info written to xenstore */
+		n = pread(fd, buf, sizeof(buf), 0);
+		buf[n] = 0;
+		meminfo_data = parse(buf);
+		if (meminfo_data)
+			send_to_qmemman(xs, meminfo_data);
+		if (fork() > 0)
+			exit(0);
+	}
+
+	for (;;) {
+		n = pread(fd, buf, sizeof(buf), 0);
+		buf[n] = 0;
+		meminfo_data = parse(buf);
+		if (meminfo_data)
+			send_to_qmemman(xs, meminfo_data);
+		usleep(delay);
+	}
+}

qmemman/qubes-meminfo-writer-dom0.service

@@ -0,0 +1,13 @@
+[Unit]
+Description=Qubes memory information reporter
+After=qubes-core.service qubes-qmemman.service
+ConditionPathExists=/var/run/qubes/qmemman.sock
+
+[Service]
+Type=simple
+ExecStart=/usr/sbin/meminfo-writer 30000 100000
+StandardOutput=syslog
+RemainAfterExit=yes
+
+[Install]
+WantedBy=multi-user.target

qmemman/qubes-meminfo-writer.service

@@ -0,0 +1,12 @@
+[Unit]
+Description=Qubes memory information reporter
+ConditionPathExists=/var/run/qubes-service/meminfo-writer
+
+[Service]
+Type=forking
+ExecStart=/usr/sbin/meminfo-writer 30000 100000 /var/run/meminfo-writer.pid
+PIDFile=/var/run/meminfo-writer.pid
+StandardOutput=syslog
+
+[Install]
+WantedBy=multi-user.target

rpm_spec/qubes-utils.spec

@@ -34,6 +34,21 @@ make all
 %install
 make install DESTDIR=%{buildroot}
 
+%post
+if [ -r /etc/qubes-release ]; then
+    # dom0
+    /bin/systemctl enable qubes-meminfo-writer-dom0.service > /dev/null 2>&1
+else
+    # VM
+    /bin/systemctl enable qubes-meminfo-writer.service > /dev/null 2>&1
+fi
+
+%postun
+if [ $1 -eq 0 ]; then
+    /bin/systemctl disable qubes-meminfo-writer.service > /dev/null 2>&1
+    /bin/systemctl disable qubes-meminfo-writer.service > /dev/null 2>&1
+fi
+
 %clean
 rm -rf $RPM_BUILD_ROOT
 
@@ -41,6 +56,9 @@ rm -rf $RPM_BUILD_ROOT
 %defattr(-,root,root,-)
 /etc/udev/rules.d/99-qubes-*.rules
 /usr/libexec/qubes/udev-*
+%{_sbindir}/meminfo-writer
+%{_unitdir}/qubes-meminfo-writer.service
+%{_unitdir}/qubes-meminfo-writer-dom0.service
 
 
 %files devel