file: support using dynamic script handlers as error pages

Rework the current request handler code to not require an error page path
to be an actual file system entity.

Signed-off-by: Jo-Philipp Wich <jo@mein.io>

diff --git a/file.c b/file.c
index 15489007e460f1ed1cec27921d1276a2c5d9a0e7..ac781c1acce43b60ff9f54363bc3ce5c5a8d32f1 100644 (file)
--- a/file.c
+++ b/file.c
@@ -49,6 +49,7 @@ struct deferred_request {
        struct dispatch_handler *d;
        struct client *cl;
        struct path_info pi;
+       char *url;
        bool called, path;
 };
 
@@ -631,7 +632,7 @@ static void uh_file_data(struct client *cl, struct path_info *pi, int fd)
        file_write_cb(cl);
 }
 
-static bool __handle_file_request(struct client *cl, char *url);
+static bool __handle_file_request(struct client *cl, char *url, bool is_error_handler);
 
 static void uh_file_request(struct client *cl, const char *url,
                            struct path_info *pi, struct blob_attr **tb)
@@ -684,7 +685,7 @@ error:
                req->redirect_status = 403;
                error_handler = alloca(strlen(conf.error_handler) + 1);
                strcpy(error_handler, conf.error_handler);
-               if (__handle_file_request(cl, error_handler))
+               if (__handle_file_request(cl, error_handler, true))
                        return;
        }
 
@@ -728,10 +729,8 @@ dispatch_find(const char *url, struct path_info *pi)
 }
 
 static void
-uh_invoke_script(struct client *cl, struct dispatch_handler *d, struct path_info *pi)
+uh_invoke_script(struct client *cl, struct dispatch_handler *d, char *url, struct path_info *pi)
 {
-       char *url = blobmsg_data(blob_data(cl->hdr.head));
-
        n_requests++;
        d->handle_request(cl, url, pi);
 }
@@ -752,7 +751,7 @@ static void uh_complete_request(struct client *cl)
                cl = dr->cl;
                dr->called = true;
                cl->dispatch.data_blocked = false;
-               uh_invoke_script(cl, dr->d, dr->path ? &dr->pi : NULL);
+               uh_invoke_script(cl, dr->d, dr->url, dr->path ? &dr->pi : NULL);
                client_poll_post_data(cl);
                ustream_poll(cl->us);
        }
@@ -787,10 +786,10 @@ static int field_len(const char *ptr)
        _field(query)
 
 static void
-uh_defer_script(struct client *cl, struct dispatch_handler *d, struct path_info *pi)
+uh_defer_script(struct client *cl, struct dispatch_handler *d, char *url, struct path_info *pi)
 {
        struct deferred_request *dr;
-       char *_root, *_phys, *_name, *_info, *_query;
+       char *_url, *_root, *_phys, *_name, *_info, *_query;
 
        cl->dispatch.req_free = uh_free_pending_request;
 
@@ -798,7 +797,7 @@ uh_defer_script(struct client *cl, struct dispatch_handler *d, struct path_info
                /* allocate enough memory to duplicate all path_info strings in one block */
 #undef _field
 #define _field(_name) &_##_name, field_len(pi->_name),
-               dr = calloc_a(sizeof(*dr), path_info_fields NULL);
+               dr = calloc_a(sizeof(*dr), &_url, strlen(url), path_info_fields NULL);
 
                memcpy(&dr->pi, pi, sizeof(*pi));
                dr->path = true;
@@ -808,11 +807,12 @@ uh_defer_script(struct client *cl, struct dispatch_handler *d, struct path_info
 #define _field(_name) if (pi->_name) dr->pi._name = strcpy(_##_name, pi->_name);
                path_info_fields
        } else {
-               dr = calloc(1, sizeof(*dr));
+               dr = calloc_a(sizeof(*dr), &_url, strlen(url), NULL);
        }
 
        cl->dispatch.req_data = dr;
        cl->dispatch.data_blocked = true;
+       dr->url = strcpy(_url, url);
        dr->cl = cl;
        dr->d = d;
        list_add(&dr->list, &pending_requests);
@@ -825,13 +825,13 @@ uh_invoke_handler(struct client *cl, struct dispatch_handler *d, char *url, stru
                return d->handle_request(cl, url, pi);
 
        if (n_requests >= conf.max_script_requests)
-               return uh_defer_script(cl, d, pi);
+               return uh_defer_script(cl, d, url, pi);
 
        cl->dispatch.req_free = uh_complete_request;
-       uh_invoke_script(cl, d, pi);
+       uh_invoke_script(cl, d, url, pi);
 }
 
-static bool __handle_file_request(struct client *cl, char *url)
+static bool __handle_file_request(struct client *cl, char *url, bool is_error_handler)
 {
        static const struct blobmsg_policy hdr_policy[__HDR_MAX] = {
                [HDR_AUTHORIZATION] = { "authorization", BLOBMSG_TYPE_STRING },
@@ -846,6 +846,16 @@ static bool __handle_file_request(struct client *cl, char *url)
        struct path_info *pi;
        char *user, *pass, *auth;
 
+       if (is_error_handler) {
+               d = dispatch_find(url, NULL);
+
+               if (d) {
+                       uh_invoke_handler(cl, d, url, NULL);
+
+                       return true;
+               }
+       }
+
        pi = uh_path_lookup(cl, url);
        if (!pi)
                return false;
@@ -931,7 +941,7 @@ void uh_handle_request(struct client *cl)
        if (d)
                return uh_invoke_handler(cl, d, url, NULL);
 
-       if (__handle_file_request(cl, url))
+       if (__handle_file_request(cl, url, false))
                return;
 
        if (uh_handler_run(cl, &url, true)) {
@@ -939,7 +949,7 @@ void uh_handle_request(struct client *cl)
                        return;
 
                uh_handler_run(cl, &url, false);
-               if (__handle_file_request(cl, url))
+               if (__handle_file_request(cl, url, false))
                        return;
        }
 
@@ -947,7 +957,7 @@ void uh_handle_request(struct client *cl)
        if (conf.error_handler) {
                error_handler = alloca(strlen(conf.error_handler) + 1);
                strcpy(error_handler, conf.error_handler);
-               if (__handle_file_request(cl, error_handler))
+               if (__handle_file_request(cl, error_handler, true))
                        return;
        }