1 files changed, 203 insertions, 1 deletions

diff --git a/src/version.c b/src/version.c
index d8f264c..a5e63a0 100644
--- a/src/version.c
+++ b/src/version.c
@@ -21,6 +21,8 @@ const char *const l2_version__messages[] = {
   "Allocation failed",
   "OS error",
   "Error downloading version manifest",
+  "Version not found",
+  "Max recursion depth exceeded",
   NULL
 };
 
@@ -46,12 +48,183 @@ done:
   return r;
 }
 
-unsigned l2_version_load_local(const char *name)
+void l2_version__load_local(const char *id, size_t expectsz, l2_sha1_digest_t *digest, json_t **ojson);
+bool l2_version__download_remote(struct l2_version_remote *remote, json_t **ojson);
+
+unsigned l2_version__load_or_download(const char *name, json_t **ojs)
 {
+  json_t *js = NULL;
+  struct l2_version_remote *remote = NULL;
   
+  for (struct l2_version_remote *cur = l2_state.ver_remote_head; cur; cur = cur->next) {
+    if (!strcmp(cur->id, name)) {
+      remote = cur;
+      break;
+    }
+  }
+
+  if (remote) {
+    l2_version__load_local(remote->id, 0, &remote->sha1, &js);
+    if (!js) {
+      CMD_DEBUG0("local version not found, downloading");
+      if (!l2_version__download_remote(remote, &js) || !js)
+        return VERSION_EDOWNLOAD;
+    }
+  } else {
+    l2_version__load_local(remote->id, 0, NULL, &js);
+    if (!js) return VERSION_ENOTFOUND;
+  }
+
+  *ojs = js;
   return VERSION_SUCCESS;
 }
 
+unsigned l2_version__load_recursive(const char *name, json_t *target, int depth)
+{
+  json_t *other = NULL;
+  json_t *inherit;
+
+  if (depth <= 0) return VERSION_ERECURSE;
+
+  unsigned res = l2_version__load_or_download(name, &other);
+
+  if (res != VERSION_SUCCESS) return res;
+  l2_json_merge_objects(target, other);
+
+  inherit = json_object_get(other, "inheritsFrom");
+  if (!json_is_string(inherit)) {
+    json_decref(other);
+    return VERSION_SUCCESS;
+  }
+
+  json_decref(other);
+  return l2_version__load_recursive(json_string_value(inherit), target, depth - 1);
+}
+
+unsigned l2_version_load_local(const char *name, json_t **ojson)
+{
+  json_t *js = json_object();
+  if (!js) return VERSION_EJSON;
+
+  unsigned res = l2_version__load_recursive(name, js, 10);
+  *ojson = js;
+  return res;
+}
+
+void l2_version__load_local(const char *id, size_t expectsz, l2_sha1_digest_t *digest, json_t **ojson)
+{
+  char *path;
+  size_t temp;
+  L2_ASPRINTF(path, temp, "%s/versions/%s/%s.json", l2_state.paths.data, id, id);
+ 
+  FILE *ver = fopen(path, "r");
+  if (!ver) return;
+
+  int res = l2_version_check_integrity(ver, digest, expectsz);
+  if (res < 0) {
+    CMD_WARN("Error checking version file integrity for %s", id);
+    return;
+  } else if (res == 0) {
+    CMD_DEBUG("Version %s (%s) has bad integrity", id, path);
+    return;
+  }
+
+  json_t *js;
+  json_error_t jerr;
+
+  rewind(ver);
+  js = json_loadf(ver, JSON_REJECT_DUPLICATES, &jerr);
+  if (!js) {
+    CMD_WARN("JSON error loading %s: %s", id, jerr.text);
+    return;
+  }
+
+  *ojson = js;
+}
+
+/* downloads a remote version */
+bool l2_version__download_remote(struct l2_version_remote *remote, json_t **ojson)
+{
+  char *dirname;
+  char *fname;
+  size_t temp;
+  FILE *save = NULL;
+  json_t *js = NULL;
+  L2_ASPRINTF(dirname, temp, "%s/versions/%s", l2_state.paths.data, remote->id);
+  L2_ASPRINTF(fname, temp, "%s/%s.json", dirname, remote->id);
+
+  if (l2_launcher_mkdir_parents(dirname) < 0) {
+    CMD_ERROR("Could not create directory for %s: %s", remote->id, strerror(errno));
+    return false;
+  }
+
+  CURL *cu = curl_easy_init();
+  l2_sha1_state_t st;
+  l2_sha1_digest_t dig;
+  json_error_t err;
+  if (!cu) return false;
+
+  void *data = NULL;
+  char errbuf[CURL_ERROR_SIZE];
+  size_t sz;
+
+  memset(errbuf, 0, CURL_ERROR_SIZE * sizeof(char));
+
+  curl_easy_setopt(cu, CURLOPT_ERRORBUFFER, errbuf);
+  CURLcode code = l2_launcher_download(cu, remote->url, &data, &sz);
+
+  if (code != CURLE_OK) {
+    CMD_WARN("Error downloading version %s: %s: %s", remote->id, curl_easy_strerror(code), errbuf);
+    goto cleanup;
+  }
+
+  l2_sha1_init(&st);
+  l2_sha1_update(&st, data, sz);
+  l2_sha1_finalize(&st, &dig);
+
+  if (l2_sha1_digest_compare(&dig, &remote->sha1)) {
+    char d1[L2_SHA1_DIGESTLEN + 1];
+    char d2[L2_SHA1_DIGESTLEN + 1];
+
+    l2_sha1_digest_to_hex(&dig, d1);
+    l2_sha1_digest_to_hex(&remote->sha1, d2);
+
+    CMD_WARN("Downloaded file for %s has incorrect hash: expected %s, got %s!", remote->id, d2, d1);
+    goto cleanup;
+  }
+
+  js = json_loadb(data, sz, JSON_REJECT_DUPLICATES, &err);
+  if (!js) {
+    CMD_WARN("JSON parse error reading version %s: %s", remote->id, err.text);
+    goto cleanup;
+  }
+
+  save = fopen(fname, "w");
+  if (!save) {
+    CMD_WARN("Error opening version file %s", fname);
+    goto cleanup;
+  }
+
+  if (fwrite(data, sz, 1, save) < 1) {
+    CMD_WARN("Error saving version info to %s", fname);
+    goto cleanup;
+  }
+
+  *ojson = js;
+
+  curl_easy_cleanup(cu);
+  fclose(save);
+  free(data);
+  return true;
+
+cleanup:
+  curl_easy_cleanup(cu);
+  free(data);
+  if (save) fclose(save);
+  if (js) json_decref(js);
+  return false;
+}
+
 char *l2_version__read_etag(time_t *lastmod)
 {
   size_t dpathlen = strlen(l2_state.paths.data);
@@ -386,3 +559,32 @@ cleanup:
 
   return res;
 }
+
+int l2_version_check_integrity(FILE *fp, l2_sha1_digest_t *digest, size_t sz)
+{
+  #define VER_READBUF_SZ (1024)
+
+  size_t len = 0, nread;
+  uint8_t buf[VER_READBUF_SZ];
+  l2_sha1_digest_t rdigest;
+  l2_sha1_state_t st;
+
+  l2_sha1_init(&st);
+
+  while ((nread = fread(buf, 1, VER_READBUF_SZ, fp)) > 0) {
+    len += nread;
+    l2_sha1_update(&st, buf, nread);
+  }
+
+  if (ferror(fp)) return -1;
+
+  l2_sha1_finalize(&st, &rdigest);
+
+  if (sz > 0 && sz != len) return 0;
+
+  if (digest) {
+    return !l2_sha1_digest_compare(&rdigest, digest) ? 1 : 0;
+  } else {
+    return 1;
+  }
+}