1 files changed, 176 insertions, 0 deletions
diff --git a/src/launcherutil.c b/src/launcherutil.c
index f7a38fd..2db6238 100644
--- a/src/launcherutil.c
+++ b/src/launcherutil.c
@@ -281,3 +281,179 @@ int l2_json_merge_objects(json_t *j1, json_t *j2)
 
   return 0;
 }
+
+int l2_launcher_check_integrity(FILE *fp, const 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;
+
+  if (!digest && sz == 0) return 1;
+
+  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;
+  }
+}
+
+int l2_launcher_should_download(const char *path, const l2_sha1_digest_t *expectdigest, size_t expectsize)
+{
+  FILE *lfile = fopen(path, "rb");
+
+  if (!lfile) {
+    if (errno == ENOENT) {
+      return 1;
+    } else {
+      CMD_DEBUG("Failed to open %s for reading: %s", path, strerror(errno));
+      return -1;
+    }
+  }
+
+  int res = l2_launcher_check_integrity(lfile, expectdigest, expectsize);
+  fclose(lfile);
+
+  switch (res) {
+    case 0:
+      CMD_DEBUG("SHOULD redownload %s, the SHA1 or size doesn't match.", path);
+      return 1;
+    case 1:
+      CMD_DEBUG("SHOULDN'T redownload %s.", path);
+      return 0;
+    default:
+      return res;
+  }
+}
+
+struct l2_launcher__download_data {
+  l2_sha1_state_t digest_state;
+  size_t recv_size;
+  FILE *fp;
+};
+
+size_t l2_launcher__download_writecb(char *ptr, size_t size, size_t nmemb, void *user)
+{
+  struct l2_launcher__download_data *data = user;
+  size_t realsz = size * nmemb; /* size should be 1 but whatever */
+
+  if (fwrite(ptr, size, nmemb, data->fp) < nmemb) {
+    return CURL_WRITEFUNC_ERROR;
+  }
+
+  l2_sha1_update(&data->digest_state, ptr, realsz);
+  data->recv_size += realsz;
+
+  return realsz;
+}
+
+int l2_launcher_download_checksummed(const char *url, const char *pathstr, l2_sha1_digest_t *expect_digest, size_t expect_size)
+{
+  int res = -1;
+  CURL *pc = NULL;
+
+  /* check if we even need to redownload the thing */
+  int rdres = l2_launcher_should_download(pathstr, expect_digest, expect_size);
+  if (rdres < 0) {
+    return -1;
+  } else if (!rdres) {
+    CMD_DEBUG("Not downloading %s", pathstr);
+    return 0;
+  }
+
+  if (!url) {
+    CMD_WARN("Cannot redownload %s, even though I need to! (no URL specified)", pathstr);
+    return -1;
+  }
+
+  /* redownload the file */
+  struct l2_launcher__download_data dldata;
+  char errbuf[CURL_ERROR_SIZE];
+
+  memset(&dldata, 0, sizeof(struct l2_launcher__download_data));
+  memset(&errbuf, 0, sizeof(errbuf));
+
+  l2_sha1_init(&dldata.digest_state);
+
+  if (l2_launcher_mkdir_parents_ex(pathstr, 1) < 0) {
+    goto cleanup;
+  }
+
+  dldata.fp = fopen(pathstr, "wb");
+  if (!dldata.fp) {
+    CMD_WARN("Failed to open %s for writing: %s", pathstr, strerror(errno));
+    goto cleanup;
+  }
+
+  pc = curl_easy_init();
+  if (!pc) {
+    goto cleanup;
+  }
+
+  curl_easy_setopt(pc, CURLOPT_USERAGENT, L2_USER_AGENT);
+  curl_easy_setopt(pc, CURLOPT_URL, url);
+  curl_easy_setopt(pc, CURLOPT_WRITEDATA, &dldata);
+  curl_easy_setopt(pc, CURLOPT_WRITEFUNCTION, &l2_launcher__download_writecb);
+  curl_easy_setopt(pc, CURLOPT_ERRORBUFFER, errbuf);
+
+  CURLcode cres = curl_easy_perform(pc);
+  if (cres != CURLE_OK) {
+    CMD_WARN("Failed to download %s: %s: %s", pathstr, curl_easy_strerror(cres), errbuf);
+    goto cleanup;
+  }
+
+  fclose(dldata.fp);
+  dldata.fp = NULL;
+
+  curl_easy_cleanup(pc);
+  pc = NULL;
+
+  l2_sha1_digest_t recvdigest;
+  l2_sha1_finalize(&dldata.digest_state, &recvdigest);
+  
+  if (expect_digest && l2_sha1_digest_compare(&recvdigest, expect_digest)) {
+    char expstr[L2_SHA1_HEX_STRLEN + 1];
+    char gotstr[L2_SHA1_HEX_STRLEN + 1];
+
+    l2_sha1_digest_to_hex(expect_digest, expstr);
+    l2_sha1_digest_to_hex(&recvdigest, gotstr);
+
+    CMD_WARN("Downloaded %s has wrong digest! (expected: %s, got: %s)", pathstr, expstr, gotstr);
+    if (unlink(pathstr) < 0) {
+      CMD_WARN("Failed to delete %s: %s", pathstr, strerror(errno));
+    }
+    goto cleanup;
+  }
+
+  if (expect_size > 0 && expect_size != dldata.recv_size) {
+    CMD_WARN("Downloaded %s has wrong size! (expected: %zu bytes, got: %zu bytes)", pathstr, expect_size, dldata.recv_size);
+    if (unlink(pathstr) < 0) {
+      CMD_WARN("Failed to delete %s: %s", pathstr, strerror(errno));
+    }
+    goto cleanup;
+  }
+  
+  CMD_INFO("Downloaded %s successfully.", pathstr);
+  curl_easy_cleanup(pc);
+  return 1;
+
+cleanup:
+  if (dldata.fp) fclose(dldata.fp);
+  if (pc) curl_easy_cleanup(pc);
+  return res;
+}