1 files changed, 103 insertions, 0 deletions
diff --git a/src/lib/ipwd.c b/src/lib/ipwd.c
new file mode 100644
index 0000000..8ac81fa
--- /dev/null
+++ b/src/lib/ipwd.c
@@ -0,0 +1,103 @@
+/* Copyright (c) 2011-2018 Dovecot authors, see the included COPYING file */
+
+#define _POSIX_PTHREAD_SEMANTICS /* for Solaris */
+#include "lib.h"
+#include "ipwd.h"
+
+#include <unistd.h>
+
+#define PWBUF_MIN_SIZE 128
+#define GRBUF_MIN_SIZE 128
+
+static void *pwbuf = NULL, *grbuf = NULL;
+static size_t pwbuf_size, grbuf_size;
+
+static void pw_init(void)
+{
+	size_t old_pwbuf_size = pwbuf_size;
+
+	if (pwbuf == NULL || errno == ERANGE) {
+		pwbuf_size = nearest_power(old_pwbuf_size + 1);
+		if (pwbuf_size < PWBUF_MIN_SIZE)
+			pwbuf_size = PWBUF_MIN_SIZE;
+		pwbuf = i_realloc(pwbuf, old_pwbuf_size, pwbuf_size);
+	}
+}
+
+static void gr_init(void)
+{
+	size_t old_grbuf_size = grbuf_size;
+
+	if (grbuf == NULL || errno == ERANGE) {
+		grbuf_size = nearest_power(old_grbuf_size + 1);
+		if (grbuf_size < PWBUF_MIN_SIZE)
+			grbuf_size = PWBUF_MIN_SIZE;
+		grbuf = i_realloc(grbuf, old_grbuf_size, grbuf_size);
+	}
+}
+
+void ipwd_deinit(void)
+{
+	i_free_and_null(pwbuf);
+	i_free_and_null(grbuf);
+}
+
+int i_getpwnam(const char *name, struct passwd *pwd_r)
+{
+	struct passwd *result;
+
+	errno = 0;
+	do {
+		pw_init();
+		errno = getpwnam_r(name, pwd_r, pwbuf, pwbuf_size, &result);
+	} while (errno == ERANGE);
+	if (result != NULL)
+		return 1;
+	if (errno == EINVAL) {
+		/* FreeBSD fails here when name="user@domain" */
+		return 0;
+	}
+	return errno == 0 ? 0 : -1;
+}
+
+int i_getpwuid(uid_t uid, struct passwd *pwd_r)
+{
+	struct passwd *result;
+
+	errno = 0;
+	do {
+		pw_init();
+		errno = getpwuid_r(uid, pwd_r, pwbuf, pwbuf_size, &result);
+	} while (errno == ERANGE);
+	if (result != NULL)
+		return 1;
+	return errno == 0 ? 0 : -1;
+}
+
+int i_getgrnam(const char *name, struct group *grp_r)
+{
+	struct group *result;
+
+	errno = 0;
+	do {
+		gr_init();
+		errno = getgrnam_r(name, grp_r, grbuf, grbuf_size, &result);
+	} while (errno == ERANGE);
+	if (result != NULL)
+		return 1;
+	return errno == 0 ? 0 : -1;
+}
+
+int i_getgrgid(gid_t gid, struct group *grp_r)
+{
+	struct group *result;
+
+	errno = 0;
+	do {
+		gr_init();
+		errno = getgrgid_r(gid, grp_r, grbuf, grbuf_size, &result);
+	} while (errno == ERANGE);
+	if (result != NULL)
+		return 1;
+	return errno == 0 ? 0 : -1;
+}