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Diffstat (limited to 'src/templating/templating_api.c')
| -rw-r--r-- | src/templating/templating_api.c | 524 |
1 files changed, 524 insertions, 0 deletions
diff --git a/src/templating/templating_api.c b/src/templating/templating_api.c new file mode 100644 index 000000000..88a17c682 --- /dev/null +++ b/src/templating/templating_api.c @@ -0,0 +1,524 @@ +/* + This file is part of TALER + Copyright (C) 2020, 2022 Taler Systems SA + + TALER is free software; you can redistribute it and/or modify it under the + terms of the GNU General Public License as published by the Free Software + Foundation; either version 3, or (at your option) any later version. + + TALER is distributed in the hope that it will be useful, but WITHOUT ANY + WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR + A PARTICULAR PURPOSE. See the GNU General Public License for more details. + + You should have received a copy of the GNU General Public License along with + TALER; see the file COPYING. If not, see <http://www.gnu.org/licenses/> +*/ +/** + * @file templating_api.c + * @brief logic to load and complete HTML templates + * @author Christian Grothoff + */ +#include "platform.h" +#include <gnunet/gnunet_util_lib.h> +#include "taler_util.h" +#include "taler_mhd_lib.h" +#include "taler_templating_lib.h" +#include "mustach.h" +#include "mustach-jansson.h" +#include <gnunet/gnunet_mhd_compat.h> + + +/** + * Entry in a key-value array we use to cache templates. + */ +struct TVE +{ + /** + * A name, used as the key. NULL for the last entry. + */ + char *name; + + /** + * Language the template is in. + */ + char *lang; + + /** + * 0-terminated (!) file data to return for @e name and @e lang. + */ + char *value; + +}; + + +/** + * Array of templates loaded into RAM. + */ +static struct TVE *loaded; + +/** + * Length of the #loaded array. + */ +static unsigned int loaded_length; + + +/** + * Load Mustach template into memory. Note that we intentionally cache + * failures, that is if we ever failed to load a template, we will never try + * again. + * + * @param connection the connection we act upon + * @param name name of the template file to load + * (MUST be a 'static' string in memory!) + * @return NULL on error, otherwise the template + */ +static const char * +lookup_template (struct MHD_Connection *connection, + const char *name) +{ + struct TVE *best = NULL; + const char *lang; + + lang = MHD_lookup_connection_value (connection, + MHD_HEADER_KIND, + MHD_HTTP_HEADER_ACCEPT_LANGUAGE); + if (NULL == lang) + lang = "en"; + /* find best match by language */ + for (unsigned int i = 0; i<loaded_length; i++) + { + if (0 != strcmp (loaded[i].name, + name)) + continue; /* does not match by name */ + if ( (NULL == best) || + (TALER_language_matches (lang, + loaded[i].lang) > + TALER_language_matches (lang, + best->lang) ) ) + best = &loaded[i]; + } + if (NULL == best) + { + GNUNET_log (GNUNET_ERROR_TYPE_ERROR, + "No templates found for `%s'\n", + name); + return NULL; + } + return best->value; +} + + +/** + * Get the base URL for static resources. + * + * @param con the MHD connection + * @param instance_id the instance ID + * @returns the static files base URL, guaranteed + * to have a trailing slash. + */ +static char * +make_static_url (struct MHD_Connection *con, + const char *instance_id) +{ + const char *host; + const char *forwarded_host; + const char *uri_path; + struct GNUNET_Buffer buf = { 0 }; + + host = MHD_lookup_connection_value (con, + MHD_HEADER_KIND, + "Host"); + forwarded_host = MHD_lookup_connection_value (con, + MHD_HEADER_KIND, + "X-Forwarded-Host"); + + uri_path = MHD_lookup_connection_value (con, + MHD_HEADER_KIND, + "X-Forwarded-Prefix"); + if (NULL != forwarded_host) + host = forwarded_host; + + if (NULL == host) + { + GNUNET_break (0); + return NULL; + } + + GNUNET_assert (NULL != instance_id); + + if (GNUNET_NO == TALER_mhd_is_https (con)) + GNUNET_buffer_write_str (&buf, + "http://"); + else + GNUNET_buffer_write_str (&buf, + "https://"); + GNUNET_buffer_write_str (&buf, + host); + if (NULL != uri_path) + GNUNET_buffer_write_path (&buf, + uri_path); + if (0 != strcmp ("default", + instance_id)) + { + GNUNET_buffer_write_path (&buf, + "instances"); + GNUNET_buffer_write_path (&buf, + instance_id); + } + GNUNET_buffer_write_path (&buf, + "static/"); + return GNUNET_buffer_reap_str (&buf); +} + + +int +TALER_TEMPLATING_fill (const char *tmpl, + const json_t *root, + void **result, + size_t *result_size) +{ + int eno; + + if (0 != + (eno = mustach_jansson_mem (tmpl, + 0, /* length of tmpl */ + (json_t *) root, + Mustach_With_AllExtensions, + (char **) result, + result_size))) + { + GNUNET_log (GNUNET_ERROR_TYPE_ERROR, + "mustach failed on template with error %d\n", + eno); + *result = NULL; + *result_size = 0; + return eno; + } + return eno; +} + + +enum GNUNET_GenericReturnValue +TALER_TEMPLATING_build (struct MHD_Connection *connection, + unsigned int *http_status, + const char *template, + const char *instance_id, + const char *taler_uri, + const json_t *root, + struct MHD_Response **reply) +{ + char *body; + size_t body_size; + + { + const char *tmpl; + int eno; + + tmpl = lookup_template (connection, + template); + if (NULL == tmpl) + { + GNUNET_log (GNUNET_ERROR_TYPE_ERROR, + "Failed to load template `%s'\n", + template); + *http_status = MHD_HTTP_NOT_ACCEPTABLE; + *reply = TALER_MHD_make_error (TALER_EC_GENERIC_FAILED_TO_LOAD_TEMPLATE, + template); + return GNUNET_NO; + } + /* Add default values to the context */ + if (NULL != instance_id) + { + char *static_url = make_static_url (connection, + instance_id); + + GNUNET_break (0 == + json_object_set_new ((json_t *) root, + "static_url", + json_string (static_url))); + GNUNET_free (static_url); + } + if (0 != + (eno = mustach_jansson_mem (tmpl, + 0, + (json_t *) root, + Mustach_With_NoExtensions, + &body, + &body_size))) + { + GNUNET_log (GNUNET_ERROR_TYPE_ERROR, + "mustach failed on template `%s' with error %d\n", + template, + eno); + *http_status = MHD_HTTP_INTERNAL_SERVER_ERROR; + *reply = TALER_MHD_make_error (TALER_EC_GENERIC_FAILED_TO_EXPAND_TEMPLATE, + template); + return GNUNET_NO; + } + } + + /* try to compress reply if client allows it */ + { + bool compressed = false; + + if (MHD_YES == + TALER_MHD_can_compress (connection)) + { + compressed = TALER_MHD_body_compress ((void **) &body, + &body_size); + } + *reply = MHD_create_response_from_buffer (body_size, + body, + MHD_RESPMEM_MUST_FREE); + if (NULL == *reply) + { + GNUNET_break (0); + return GNUNET_SYSERR; + } + if (compressed) + { + if (MHD_NO == + MHD_add_response_header (*reply, + MHD_HTTP_HEADER_CONTENT_ENCODING, + "deflate")) + { + GNUNET_break (0); + MHD_destroy_response (*reply); + *reply = NULL; + return GNUNET_SYSERR; + } + } + } + + /* Add standard headers */ + if (NULL != taler_uri) + GNUNET_break (MHD_NO != + MHD_add_response_header (*reply, + "Taler", + taler_uri)); + GNUNET_break (MHD_NO != + MHD_add_response_header (*reply, + MHD_HTTP_HEADER_CONTENT_TYPE, + "text/html")); + return GNUNET_OK; +} + + +enum GNUNET_GenericReturnValue +TALER_TEMPLATING_reply (struct MHD_Connection *connection, + unsigned int http_status, + const char *template, + const char *instance_id, + const char *taler_uri, + const json_t *root) +{ + enum GNUNET_GenericReturnValue res; + struct MHD_Response *reply; + MHD_RESULT ret; + + res = TALER_TEMPLATING_build (connection, + &http_status, + template, + instance_id, + taler_uri, + root, + &reply); + if (GNUNET_SYSERR == res) + return res; + ret = MHD_queue_response (connection, + http_status, + reply); + MHD_destroy_response (reply); + if (MHD_NO == ret) + return GNUNET_SYSERR; + return (res == GNUNET_OK) + ? GNUNET_OK + : GNUNET_NO; +} + + +/** + * Function called with a template's filename. + * + * @param cls closure, NULL + * @param filename complete filename (absolute path) + * @return #GNUNET_OK to continue to iterate, + * #GNUNET_NO to stop iteration with no error, + * #GNUNET_SYSERR to abort iteration with error! + */ +static enum GNUNET_GenericReturnValue +load_template (void *cls, + const char *filename) +{ + char *lang; + char *end; + int fd; + struct stat sb; + char *map; + const char *name; + + (void) cls; + if ('.' == filename[0]) + return GNUNET_OK; + name = strrchr (filename, + '/'); + if (NULL == name) + name = filename; + else + name++; + lang = strchr (name, + '.'); + if (NULL == lang) + return GNUNET_OK; /* name must include .$LANG */ + lang++; + end = strchr (lang, + '.'); + if ( (NULL == end) || + (0 != strcmp (end, + ".must")) ) + return GNUNET_OK; /* name must end with '.must' */ + + /* finally open template */ + fd = open (filename, + O_RDONLY); + if (-1 == fd) + { + GNUNET_log_strerror_file (GNUNET_ERROR_TYPE_ERROR, + "open", + filename); + + return GNUNET_SYSERR; + } + if (0 != + fstat (fd, + &sb)) + { + GNUNET_log_strerror_file (GNUNET_ERROR_TYPE_ERROR, + "fstat", + filename); + GNUNET_break (0 == close (fd)); + return GNUNET_OK; + } + map = GNUNET_malloc_large (sb.st_size + 1); + if (NULL == map) + { + GNUNET_log_strerror (GNUNET_ERROR_TYPE_ERROR, + "malloc"); + GNUNET_break (0 == close (fd)); + return GNUNET_SYSERR; + } + if (sb.st_size != + read (fd, + map, + sb.st_size)) + { + GNUNET_log_strerror_file (GNUNET_ERROR_TYPE_ERROR, + "read", + filename); + GNUNET_break (0 == close (fd)); + return GNUNET_OK; + } + GNUNET_break (0 == close (fd)); + GNUNET_array_grow (loaded, + loaded_length, + loaded_length + 1); + loaded[loaded_length - 1].name = GNUNET_strndup (name, + (lang - 1) - name); + loaded[loaded_length - 1].lang = GNUNET_strndup (lang, + end - lang); + loaded[loaded_length - 1].value = map; + return GNUNET_OK; +} + + +MHD_RESULT +TALER_TEMPLATING_reply_error ( + struct MHD_Connection *connection, + const char *template_basename, + unsigned int http_status, + enum TALER_ErrorCode ec, + const char *detail) +{ + json_t *data; + enum GNUNET_GenericReturnValue ret; + + data = GNUNET_JSON_PACK ( + GNUNET_JSON_pack_uint64 ("ec", + ec), + GNUNET_JSON_pack_string ("hint", + TALER_ErrorCode_get_hint (ec)), + GNUNET_JSON_pack_allow_null ( + GNUNET_JSON_pack_string ("detail", + detail)) + ); + ret = TALER_TEMPLATING_reply (connection, + http_status, + template_basename, + NULL, + NULL, + data); + json_decref (data); + switch (ret) + { + case GNUNET_OK: + return MHD_YES; + case GNUNET_NO: + return MHD_YES; + case GNUNET_SYSERR: + return MHD_NO; + } + GNUNET_assert (0); + return MHD_NO; +} + + +enum GNUNET_GenericReturnValue +TALER_TEMPLATING_init (const char *subsystem) +{ + char *dn; + int ret; + + { + char *path; + + path = GNUNET_OS_installation_get_path (GNUNET_OS_IPK_DATADIR); + if (NULL == path) + { + GNUNET_break (0); + return GNUNET_SYSERR; + } + GNUNET_asprintf (&dn, + "%s/%s/templates/", + path, + subsystem); + GNUNET_free (path); + } + ret = GNUNET_DISK_directory_scan (dn, + &load_template, + NULL); + GNUNET_free (dn); + if (-1 == ret) + { + GNUNET_break (0); + return GNUNET_SYSERR; + } + return GNUNET_OK; +} + + +void +TALER_TEMPLATING_done (void) +{ + for (unsigned int i = 0; i<loaded_length; i++) + { + GNUNET_free (loaded[i].name); + GNUNET_free (loaded[i].lang); + GNUNET_free (loaded[i].value); + } + GNUNET_array_grow (loaded, + loaded_length, + 0); +} + + +/* end of templating_api.c */ |