--- /dev/null
+#include <tools/ccanlint/ccanlint.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <limits.h>
+#include <errno.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <err.h>
+#include <ccan/talloc/talloc.h>
+#include <ccan/str/str.h>
+
+struct ccanlint has_license;
+
+static struct doc_section *find_license(const struct manifest *m)
+{
+ struct doc_section *d;
+
+ list_for_each(m->info_file->doc_sections, d, list) {
+ if (!streq(d->function, m->basename))
+ continue;
+ if (streq(d->type, "license"))
+ return d;
+ }
+ return NULL;
+}
+
+static const char *expected_link(const struct manifest *m,
+ struct doc_section *d)
+{
+ if (streq(d->lines[0], "GPL")
+ || streq(d->lines[0], "GPLv3")
+ || streq(d->lines[0], "GPLv3 or later")
+ || streq(d->lines[0], "GPLv3 (or later)")
+ || streq(d->lines[0], "GPL (3 or any later version)"))
+ return "../../licenses/GPL-3";
+ if (streq(d->lines[0], "GPLv2")
+ || streq(d->lines[0], "GPLv2 or later")
+ || streq(d->lines[0], "GPLv2 (or later)")
+ || streq(d->lines[0], "GPL (2 or any later version)"))
+ return "../../licenses/GPL-3";
+ if (streq(d->lines[0], "LGPL")
+ || streq(d->lines[0], "LGPLv3")
+ || streq(d->lines[0], "LGPLv3 or later")
+ || streq(d->lines[0], "LGPLv3 (or later)")
+ || streq(d->lines[0], "LGPL (3 or any later version)"))
+ return "../../licenses/LGPL-3";
+ if (streq(d->lines[0], "LGPLv2")
+ || streq(d->lines[0], "LGPLv2 or later")
+ || streq(d->lines[0], "LGPLv2 (or later)")
+ || streq(d->lines[0], "LGPL (2 or any later version)"))
+ return "../../licenses/LGPL-2.1";
+ if (streq(d->lines[0], "BSD")
+ || streq(d->lines[0], "BSD-MIT")
+ || streq(d->lines[0], "MIT"))
+ return "../../licenses/BSD-MIT";
+ return NULL;
+}
+
+static void handle_license_link(struct manifest *m, struct score *score)
+{
+ const char *link = talloc_asprintf(m, "%s/LICENSE", m->dir);
+ struct doc_section *d = find_license(m);
+ const char *ldest = expected_link(m, d);
+ char *q;
+
+ printf(
+ "Most modules want a copy of their license, so usually we create a\n"
+ "LICENSE symlink into ../../licenses to avoid too many copies.\n");
+
+ /* FIXME: make ask printf-like */
+ q = talloc_asprintf(m, "Set up link to %s (license is %s)?",
+ ldest, d->lines[0]);
+ if (ask(q)) {
+ if (symlink(ldest, link) != 0)
+ err(1, "Creating symlink %s -> %s", link, ldest);
+ }
+}
+
+static void check_has_license(struct manifest *m,
+ bool keep,
+ unsigned int *timeleft, struct score *score)
+{
+ char buf[PATH_MAX];
+ ssize_t len;
+ char *license = talloc_asprintf(m, "%s/LICENSE", m->dir);
+ const char *expected;
+ struct doc_section *d;
+
+ d = find_license(m);
+ if (!d) {
+ score->error = "No License: tag in _info";
+ return;
+ }
+ expected = expected_link(m, d);
+
+ len = readlink(license, buf, sizeof(buf));
+ if (len < 0) {
+ /* Could be a real file... OK if not a standard license. */
+ if (errno == EINVAL) {
+ if (!expected) {
+ score->pass = true;
+ return;
+ }
+ score->error
+ = talloc_asprintf(score,
+ "License in _info is '%s',"
+ " expect LICENSE symlink '%s'",
+ d->lines[0], expected);
+ return;
+ }
+ if (errno == ENOENT) {
+ score->error = "LICENSE does not exist";
+ if (expected)
+ has_license.handle = handle_license_link;
+ return;
+ }
+ err(1, "readlink on %s", license);
+ }
+ if (len >= sizeof(buf))
+ errx(1, "Reading symlink %s gave huge result", license);
+
+ buf[len] = '\0';
+
+ if (!strstarts(buf, "../../licenses/")) {
+ score->error = talloc_asprintf(score,
+ "Expected symlink to"
+ " ../../licenses/..."
+ " not %s", buf);
+ return;
+ }
+
+ if (!expected) {
+ score->error = talloc_asprintf(score,
+ "License in _info is unknown '%s',"
+ " but LICENSE symlink is '%s'",
+ d->lines[0], buf);
+ return;
+ }
+
+ if (!streq(buf, expected)) {
+ score->error = talloc_asprintf(score,
+ "Expected symlink to %s not %s",
+ expected, buf);
+ return;
+ }
+ score->pass = true;
+ score->score = score->total;
+}
+
+struct ccanlint license_exists = {
+ .key = "license_exists",
+ .name = "Module has License: entry in _info, and LICENSE symlink/file",
+ .check = check_has_license,
+ .needs = "info_exists"
+};
+
+REGISTER_TEST(license_exists);