First commit

Signed-off-by: Mattias Andrée <maandree@kth.se>

1 files changed, 154 insertions, 0 deletions

diff --git a/libaxl_parse_display.c b/libaxl_parse_display.c
new file mode 100644
index 0000000..1b304e3
--- /dev/null
+++ b/libaxl_parse_display.c
@@ -0,0 +1,154 @@
+/* See LICENSE file for copyright and license details. */
+#include "common.h"
+
+int
+libaxl_parse_display(const char *name, char **hostp, char **protocolp, int *displayp, int *screenp)
+{
+	char *p;
+	size_t n;
+	unsigned long int ul;
+	int err;
+	int saved_errno = errno;
+	struct stat st;
+
+	*hostp     = NULL;
+	*protocolp = NULL;
+	*displayp  = 0;
+	*screenp   = 0;
+
+	/* Get display server name string, if not specified */
+	if (!name || !*name) {
+		name = getenv("DISPLAY");
+		if (!name || !*name) {
+			liberror_save_backtrace(NULL);
+			liberror_set_error("No display server specified", "libaxl_parse_display", "libaxl",
+			                   LIBAXL_ERROR_NO_DISPLAY_SERVER_SPECIFIED);
+			err = LIBAXL_ERROR_NO_DISPLAY_SERVER_SPECIFIED;
+			goto fail;
+		}
+	}
+
+	/* Get path and test if protocol is "unix" */
+	p = strrchr(name, '.');
+	if (p && isdigit(*p)) {
+		errno = 0;
+		ul = strtoul(p, &p, 10);
+		if (errno || ul > (unsigned long int)INT_MAX)
+			p = NULL;
+		else
+			*screenp = (int)ul;
+	}
+	n = p ? (size_t)(p - name) : strlen(name);
+	if (n) {
+		*hostp = liberror_malloc(n + 1);
+		if (!*hostp)
+			goto errno_fail;
+		memcpy(*hostp, name, n);
+		(*hostp)[n] = '\0';
+		if (stat(*hostp, &st) || (st.st_mode & S_IFMT) != S_IFSOCK) {
+			free(*hostp);
+			*hostp = NULL;
+			goto normal;
+		}
+		*protocolp = liberror_malloc(sizeof("unix"));
+		if (!*protocolp)
+			goto errno_fail;
+		stpcpy(*protocolp, "unix");
+		goto done;
+	}
+
+normal:
+	/* Get protocol */
+	p = strrchr(name, '/');
+	if (p) {
+		n = (size_t)(p - name);
+		*protocolp = liberror_malloc(n + 1);
+		if (*protocolp)
+			goto errno_fail;
+		memcpy(*protocolp, name, n);
+		(*protocolp)[n] = '\0';
+		name = &p[1];
+	}
+
+	/* Get host */
+	p = strrchr(name, ':');
+	if (!p) {
+		liberror_save_backtrace(NULL);
+		liberror_set_error("Invalid display name: no display index", "libaxl_parse_display", "libaxl",
+		                   LIBAXL_ERROR_INVALID_DISPLAY_NAME_NO_DISPLAY_INDEX);
+		err = LIBAXL_ERROR_INVALID_DISPLAY_NAME_NO_DISPLAY_INDEX;
+		goto fail;
+	} else {
+		n = (size_t)(p - name);
+		*hostp = liberror_malloc(n + 1);
+		if (!*hostp)
+			goto errno_fail;
+		memcpy(*hostp, name, n);
+		(*hostp)[n] = '\0';
+		name = &p[1];
+	}
+
+	/* Get display */
+	if (!isdigit(*name)) {
+		liberror_save_backtrace(NULL);
+		liberror_set_error("Invalid display name: no display index", "libaxl_parse_display", "libaxl",
+		                   LIBAXL_ERROR_INVALID_DISPLAY_NAME_NO_DISPLAY_INDEX);
+		err = LIBAXL_ERROR_INVALID_DISPLAY_NAME_NO_DISPLAY_INDEX;
+		goto fail;
+	}
+	saved_errno = errno;
+	errno = 0;
+	ul = strtoul(name, (void *)&name, 10);
+	if (errno || ul > (unsigned long int)(*hostp ? 65535 - X_TCP_PORT : INT_MAX)) {
+		liberror_save_backtrace(NULL);
+		liberror_set_error("Invalid display name: display index is out of domain", "libaxl_parse_display", "libaxl",
+		                   LIBAXL_ERROR_INVALID_DISPLAY_NAME_DISPLAY_INDEX_OUT_OF_DOMAIN);
+		err = LIBAXL_ERROR_INVALID_DISPLAY_NAME_DISPLAY_INDEX_OUT_OF_DOMAIN;
+		goto fail;
+	}
+	*displayp = (int)ul;
+	errno = saved_errno;
+
+	/* Get screen */
+	if (*name)
+		goto done;
+	if (!isdigit(*name)) {
+		liberror_save_backtrace(NULL);
+		liberror_set_error("Invalid display name: invalid screen index", "libaxl_parse_display", "libaxl",
+		                   LIBAXL_ERROR_INVALID_DISPLAY_NAME_INVALID_SCREEN_INDEX);
+		err = LIBAXL_ERROR_INVALID_DISPLAY_NAME_INVALID_SCREEN_INDEX;
+		goto fail;
+	}
+	errno = 0;
+	ul = strtoul(name, (void *)&name, 10);
+	if (errno || ul > (unsigned long int)INT_MAX) {
+		liberror_save_backtrace(NULL);
+		liberror_set_error("Invalid display name: screen index is out of domain", "libaxl_parse_display", "libaxl",
+		                   LIBAXL_ERROR_INVALID_DISPLAY_NAME_SCREEN_INDEX_OUT_OF_DOMAIN);
+		err = LIBAXL_ERROR_INVALID_DISPLAY_NAME_SCREEN_INDEX_OUT_OF_DOMAIN;
+		goto fail;
+	}
+	*screenp = (int)ul;
+	if (*name) {
+		liberror_save_backtrace(NULL);
+		liberror_set_error("Invalid display name: invalid screen index", "libaxl_parse_display", "libaxl",
+		                   LIBAXL_ERROR_INVALID_DISPLAY_NAME_INVALID_SCREEN_INDEX);
+		err = LIBAXL_ERROR_INVALID_DISPLAY_NAME_INVALID_SCREEN_INDEX;
+		goto fail;
+	}
+
+done:
+	errno = saved_errno;
+	return 0;
+
+errno_fail:
+	err = LIBAXL_ERROR_SYSTEM;
+fail:
+	free(*protocolp);
+	*protocolp = NULL;
+	free(*hostp);
+	*hostp = NULL;
+	if (err != LIBAXL_ERROR_SYSTEM)
+		errno = EINVAL;
+	return err;
+}