1 files changed, 66 insertions, 0 deletions
diff --git a/process.c b/process.c
new file mode 100644
index 0000000..8303d01
--- /dev/null
+++ b/process.c
@@ -0,0 +1,66 @@
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+#include <unistd.h>
+#include <pwd.h>
+#include <sys/resource.h>
+#include <sys/prctl.h>
+#include "process.h"
+
+void drop_privileges()
+{
+	struct passwd *user;
+	struct rlimit limit;
+	
+	if (!geteuid()) {
+		user = getpwnam("nobody");
+		if (!user) {
+			perror("getpwnam");
+			exit(EXIT_FAILURE);
+		}
+		if (chroot("/var/empty")) {
+			perror("chroot");
+			exit(EXIT_FAILURE);
+		}
+		if (chdir("/")) {
+			perror("chdir");
+			exit(EXIT_FAILURE);
+		}
+		if (setresgid(user->pw_gid, user->pw_gid, user->pw_gid)) {
+			perror("setresgid");
+			exit(EXIT_FAILURE);
+		}
+		if (setgroups(1, &user->pw_gid)) {
+			perror("setgroups");
+			exit(EXIT_FAILURE);
+		}
+		if (setresuid(user->pw_uid, user->pw_uid, user->pw_uid)) {
+			perror("setresuid");
+			exit(EXIT_FAILURE);
+		}
+	}
+	limit.rlim_cur = limit.rlim_max = 8192;
+	setrlimit(RLIMIT_DATA, &limit);
+	setrlimit(RLIMIT_MEMLOCK, &limit);
+	setrlimit(RLIMIT_AS, &limit);
+	setrlimit(RLIMIT_STACK, &limit);
+	limit.rlim_cur = limit.rlim_max = 0;
+	setrlimit(RLIMIT_CORE, &limit);
+	setrlimit(RLIMIT_NPROC, &limit);
+	if (!geteuid() || !getegid()) {
+		fprintf(stderr, "Mysteriously still running as root... Goodbye.\n");
+		exit(EXIT_FAILURE);
+	}
+}
+
+void set_process_name(const char *name, int argc, char *argv[])
+{
+	char *start, *end;
+	
+	prctl(PR_SET_NAME, name);
+	end = argv[argc - 1] + strlen(argv[argc - 1]);
+	strcpy(argv[0], name);
+	start = argv[0] + strlen(argv[0]);
+	while (start < end)
+		*(start++) = '\0';
+}