Re: [Libguestfs] [PATCH nbdkit RFC 2/2] curl: Implement authorization scripts.

+/* This is called with the lock held when we must run or re-run the + * auth script. + */ +static int +run_auth_script (struct curl_handle *h) +{ + int fd; + char tmpfile[] = "/tmp/errorsXXXXXX"; + FILE *fp; + CLEANUP_FREE char *cmd = NULL, *line = NULL; + size_t len = 0, linelen = 0; + + assert (auth_script != NULL); /* checked by caller */ + + /* Reset the list of headers and cookies. */ + string_vector_iter (&script_headers, (void *) free); + string_vector_iter (&script_cookies, (void *) free); + string_vector_reset (&script_headers); + string_vector_reset (&script_cookies); + + /* Create a temporary file for the errors so we can redirect them + * into nbdkit_error. + */ + fd = mkstemp (tmpfile); + if (fd == -1) { + nbdkit_error ("mkstemp"); + return -1; + } + close (fd); + + /* Generate the full script with the local $url variable. */ + fp = open_memstream (&cmd, &len); + if (fp == NULL) { + nbdkit_error ("open_memstream: %m"); + return -1; + } + fprintf (fp, "exec </dev/null\n"); /* Avoid stdin leaking (nbdkit -s). */ + fprintf (fp, "exec 2>%s\n", tmpfile); /* Catch errors to a temporary file. */ + fprintf (fp, "url="); /* Set the shell variable. */ + shell_quote (url, fp); + putc ('\n', fp); + putc ('\n', fp); + fprintf (fp, "%s", auth_script); /* The script or command. */ + if (fclose (fp) == EOF) { + nbdkit_error ("memstream failed"); + return -1; + } + + /* Run the script and read the headers/cookies. */ + nbdkit_debug ("curl: running authorization script"); + fp = popen (cmd, "r"); + if (fp == NULL) { + nbdkit_error ("popen: %m"); + return -1; + } + while ((len = getline (&line, &linelen, fp)) != -1) { + char *p; + + if (len > 0 && line[len-1] == '\n') + line[len-1] = '\0'; + + if (strncasecmp (line, "cookie:", 7) == 0) { + p = strdup (&line[7]); + if (p == NULL || string_vector_append (&script_cookies, p) == -1) { + nbdkit_error ("malloc"); + pclose (fp); + return -1; + } + } + else { + p = strdup (line); + if (p == NULL || string_vector_append (&script_headers, p) == -1) { + nbdkit_error ("malloc"); + pclose (fp); + return -1; + } + } + } + + /* If the command failed, this should return EOF and the error + * message should be in the temporary file (but we only read the + * first line). + */ + if (pclose (fp) == EOF) { + fp = fopen (tmpfile, "r"); + if ((len = getline (&line, &linelen, fp)) >= 0) { + if (len > 0 && line[len-1] == '\n') + line[len-1] = '\0'; + nbdkit_error ("authorization script failed: %s", line); + } + else + nbdkit_error ("authorization script failed"); + return -1; + } + + nbdkit_debug ("authorization script returned %zu header(s) and %zu cookie(s)", + script_headers.size, script_cookies.size); + + return 0; +} + +static int +set_headers (struct curl_handle *h) +{ + struct curl_slist *p; + size_t i; + + /* Curl does not save a copy of the headers passed to + * CURLOPT_HTTPHEADER so we have to store it in the handle ourselves + * and be careful to unset it in the Curl handle before we free the + * list. + */ + if (h->auth_headers) { + curl_easy_setopt (h->c, CURLOPT_HTTPHEADER, NULL); + curl_slist_free_all (h->auth_headers); + h->auth_headers = NULL; + } + + /* Copy the header=... parameters. */ + for (p = headers; p != NULL; p = p->next) { + h->auth_headers = curl_slist_append (h->auth_headers, p->data); + if (h->auth_headers == NULL) { + nbdkit_error ("curl_slist_append: %m"); + return -1; + } + } + + /* Copy the headers output by the script. */ + for (i = 0; i < script_headers.size; ++i) { + h->auth_headers = + curl_slist_append (h->auth_headers, script_headers.ptr[i]); + if (h->auth_headers == NULL) { + nbdkit_error ("curl_slist_append: %m"); + return -1; + } + } + + /* Set them in the handle. */ + curl_easy_setopt (h->c, CURLOPT_HTTPHEADER, h->auth_headers); + return 0; +} + +static int +set_cookies (struct curl_handle *h) +{ + CLEANUP_FREE char *s = NULL; + size_t i; + + /* For cookies we have to append the cookies from the command line + * with the cookies from the auth script. Either might be empty. + */ + if (cookie != NULL) { + s = strdup (cookie); + if (s == NULL) { + nbdkit_error ("strdup: %m"); + return -1; + } + } + + for (i = 0; i < script_cookies.size; ++i) { + char *ns; + + if (asprintf (&ns, "%s%s%s", + s ? s : "", + s ? " ; " : "", + script_cookies.ptr[i]) == -1) { + nbdkit_error ("asprintf: %m"); + return -1; + } + s = ns; + } + + /* Curl saves a copy of this string in the handle so it's OK to free + * it after calling this. + */ + if (s) + curl_easy_setopt (h->c, CURLOPT_COOKIE, s); + + return 0; +}