From bbdd82e2953e8aad8eaa432a93e631422da17470 Mon Sep 17 00:00:00 2001
From: netblue30 <netblue30@protonmail.com>
Date: Fri, 20 May 2022 10:50:21 -0400
Subject: --oom

---
 src/firejail/oom.c | 87 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 87 insertions(+)
 create mode 100644 src/firejail/oom.c

(limited to 'src')

diff --git a/src/firejail/oom.c b/src/firejail/oom.c
new file mode 100644
index 000000000..11d08fc48
--- /dev/null
+++ b/src/firejail/oom.c
@@ -0,0 +1,87 @@
+/*
+ * Copyright (C) 2014-2022 Firejail Authors
+ *
+ * This file is part of firejail project
+ *
+ * This program 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 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program 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 program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+#include "firejail.h"
+#include <sys/wait.h>
+
+void oom_set(const char *oom_string) {
+	int oom = atoi(oom_string);
+	uid_t uid = getuid();
+	if (uid == 0) {
+		if (oom < -1000 || oom > 1000) {
+			fprintf(stderr, "Error: invalid oom value (-1000 to 1000)\n");
+			exit(1);
+		}
+	}
+	else {
+		if (oom < 0 || oom > 1000) {
+			fprintf(stderr, "Error: invalid oom value (0 to 1000)\n");
+			exit(1);
+		}
+	}
+
+	pid_t parent = getpid();
+	pid_t child = fork();
+	if (child == -1)
+		errExit("fork");
+	if (child == 0) {
+		EUID_ROOT();
+		// elevate privileges
+		if (setreuid(0, 0))
+			errExit("setreuid");
+		if (setregid(0, 0))
+			errExit("setregid");
+
+		char *fname;
+		if (asprintf(&fname, "/proc/%d/oom_score_adj", parent) == -1)
+			errExit("asprintf");
+		FILE *fp = fopen(fname, "w");
+		if (!fp) {
+			fprintf(stderr, "Error: cannot open %s\n", fname);
+			exit(1);
+		}
+		fprintf(fp, "%d", oom);
+		fclose(fp);
+		free(fname);
+
+		if (asprintf(&fname, "/proc/%d/oom_score", parent) == -1)
+			errExit("asprintf");
+		fp = fopen(fname, "r");
+		if (!fp) {
+			fprintf(stderr, "Error: cannot open %s\n", fname);
+			exit(1);
+		}
+		int newoom;
+		if (1 != fscanf(fp, "%d", &newoom)) {
+			fprintf(stderr, "Error: connot read from %s\n", fname);
+			exit(1);
+		}
+		fclose(fp);
+		free(fname);
+
+		if (!arg_quiet)
+			printf("Out-Of-Memory score adjusted, new value %d\n", newoom);
+		exit(0);
+	}
+
+	int status;
+	if (waitpid(child, &status, 0) == -1 )
+		errExit("waitpid");
+}
+
-- 
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