1 files changed, 69 insertions, 0 deletions
diff --git a/src/lib/hostpid.c b/src/lib/hostpid.c
new file mode 100644
index 0000000..3e91ade
--- /dev/null
+++ b/src/lib/hostpid.c
@@ -0,0 +1,69 @@
+/* Copyright (c) 2002-2018 Dovecot authors, see the included COPYING file */
+
+#include "lib.h"
+#include "hostpid.h"
+
+#include <unistd.h>
+#include <netdb.h>
+
+#define HOSTNAME_DISALLOWED_CHARS "/\r\n\t"
+
+const char *my_hostname = NULL;
+const char *my_pid = NULL;
+
+static char *my_hostname_dup = NULL;
+static char *my_domain = NULL;
+
+void hostpid_init(void)
+{
+	static char pid[MAX_INT_STRLEN];
+	char hostname[256];
+	const char *value;
+
+	/* allow calling hostpid_init() multiple times to reset hostname */
+	i_free_and_null(my_hostname_dup);
+	i_free_and_null(my_domain);
+
+	value = getenv(MY_HOSTNAME_ENV);
+	if (value == NULL) {
+		if (gethostname(hostname, sizeof(hostname)-1) < 0)
+			i_fatal("gethostname() failed: %m");
+		hostname[sizeof(hostname)-1] = '\0';
+		value = hostname;
+	}
+
+	if (value[0] == '\0' ||
+	    strcspn(value, HOSTNAME_DISALLOWED_CHARS) != strlen(value))
+		i_fatal("Invalid system hostname: '%s'", value);
+	my_hostname_dup = i_strdup(value);
+	my_hostname = my_hostname_dup;
+
+	i_snprintf(pid, sizeof(pid), "%lld", (long long)getpid());
+	my_pid = pid;
+}
+
+void hostpid_deinit(void)
+{
+	i_free(my_hostname_dup);
+	i_free(my_domain);
+}
+
+const char *my_hostdomain(void)
+{
+	struct hostent *hent;
+	const char *name;
+
+	if (my_domain == NULL) {
+		name = getenv(MY_HOSTDOMAIN_ENV);
+		if (name == NULL) {
+			hent = gethostbyname(my_hostname);
+			name = hent != NULL ? hent->h_name : NULL;
+			if (name == NULL) {
+				/* failed, use just the hostname */
+				name = my_hostname;
+			}
+		}
+		my_domain = i_strdup(name);
+	}
+	return my_domain;
+}