toolbox: add prlimit command

adb shell prlimit <pid> <cur> <max>

prlimit uses prlimit internally to allow you to set the limits on an arbitrary
process, if you have the privileges to.

Change-Id: Ie9a5dc510c7c695debd8f948361d4c51befa5604
Signed-off-by: Iliyan Malchev <malchev@google.com>
diff --git a/toolbox/prlimit.c b/toolbox/prlimit.c
new file mode 100644
index 0000000..8cf202a
--- /dev/null
+++ b/toolbox/prlimit.c
@@ -0,0 +1,76 @@
+/*
+ * Copyright (c) 2014, The Android Open Source Project
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *  * Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ *  * Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ *  * Neither the name of Google, Inc. nor the names of its contributors
+ *    may be used to endorse or promote products derived from this
+ *    software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
+ * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#include <stdio.h>
+#include <unistd.h>
+#include <stdlib.h>
+#include <sys/time.h>
+#include <sys/resource.h>
+
+static void
+usage(const char *s)
+{
+    fprintf(stderr, "usage: %s pid resource cur max\n", s);
+    exit(EXIT_FAILURE);
+}
+
+int prlimit_main(int argc, char *argv[])
+{
+    pid_t pid;
+    struct rlimit64 rl;
+    int resource;
+    int rc;
+
+    if (argc != 5)
+        usage(*argv);
+
+    if (sscanf(argv[1], "%d", &pid) != 1)
+        usage(*argv);
+
+    if (sscanf(argv[2], "%d", &resource) != 1)
+        usage(*argv);
+
+    if (sscanf(argv[3], "%llu", &rl.rlim_cur) != 1)
+        usage(*argv);
+
+    if (sscanf(argv[4], "%llu", &rl.rlim_max) != 1)
+        usage(*argv);
+
+    printf("setting resource %d of pid %d to [%llu,%llu]\n", resource, pid,
+            rl.rlim_cur, rl.rlim_max);
+    rc = prlimit64(pid, resource, &rl, NULL);
+    if (rc < 0) {
+        perror("prlimit");
+        exit(EXIT_FAILURE);
+    }
+
+    return 0;
+}