handler.c

   1 /*
   2  * uhttpd - Tiny single-threaded httpd
   3  *
   4  *   Copyright (C) 2015 Felix Fietkau <nbd@openwrt.org>
   5  *
   6  * Permission to use, copy, modify, and/or distribute this software for any
   7  * purpose with or without fee is hereby granted, provided that the above
   8  * copyright notice and this permission notice appear in all copies.
   9  *
  10  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
  11  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
  12  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
  13  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
  14  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
  15  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
  16  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  17  */
  18
  19 #include <libubox/blobmsg.h>
  20 #include <libubox/blobmsg_json.h>
  21 #include <libubox/json_script.h>
  22
  23 #include "uhttpd.h"
  24
  25 struct handler {
  26         struct list_head list;
  27
  28         struct json_script_file *request;
  29         struct json_script_file *fallback;
  30 };
  31
  32 static LIST_HEAD(handlers);
  33 static struct json_script_ctx handler_ctx;
  34 static struct env_var *cur_vars;
  35 static struct blob_buf b;
  36 static int handler_ret;
  37 static struct client *cur_client;
  38 static char **cur_url;
  39
  40 static void
  41 handle_redirect(struct json_script_ctx *ctx, struct blob_attr *data)
  42 {
  43         struct client *cl = cur_client;
  44         static struct blobmsg_policy policy[3] = {
  45                  { .type = BLOBMSG_TYPE_STRING },
  46                  { .type = BLOBMSG_TYPE_INT32 },
  47                  { .type = BLOBMSG_TYPE_STRING },
  48         };
  49         struct blob_attr *tb[3];
  50         const char *status = "Found";
  51         int code = 302;
  52
  53         blobmsg_parse_array(policy, ARRAY_SIZE(policy), tb, blobmsg_data(data), blobmsg_data_len(data));
  54         if (!tb[0])
  55                 return;
  56
  57         if (tb[1]) {
  58                 code = blobmsg_get_u32(tb[1]);
  59                 if (tb[2])
  60                         status = blobmsg_get_string(tb[2]);
  61         }
  62
  63         uh_http_header(cl, code, status);
  64         if (!uh_use_chunked(cl))
  65                 ustream_printf(cl->us, "Content-Length: 0\r\n");
  66         ustream_printf(cl->us, "Location: %s\r\n\r\n",
  67                        blobmsg_get_string(tb[0]));
  68         uh_request_done(cl);
  69         *cur_url = NULL;
  70
  71         handler_ret = 1;
  72         json_script_abort(ctx);
  73 }
  74
  75 static void
  76 handle_set_uri(struct json_script_ctx *ctx, struct blob_attr *data)
  77 {
  78         struct client *cl = cur_client;
  79         static struct blobmsg_policy policy = {
  80                  .type = BLOBMSG_TYPE_STRING,
  81         };
  82         struct blob_attr *tb;
  83         struct blob_attr *old_url = blob_data(cl->hdr.head);
  84
  85         blobmsg_parse_array(&policy, 1, &tb, blobmsg_data(data), blobmsg_data_len(data));
  86         if (!tb)
  87                 return;
  88
  89         blob_buf_init(&b, 0);
  90         blob_put_raw(&b, blob_next(old_url), blob_len(cl->hdr.head) - blob_pad_len(old_url));
  91
  92         /* replace URL in client header cache */
  93         blob_buf_init(&cl->hdr, 0);
  94         blobmsg_add_string(&cl->hdr, "URL", blobmsg_get_string(tb));
  95         blob_put_raw(&cl->hdr, blob_data(b.head), blob_len(b.head));
  96         *cur_url = blobmsg_data(blob_data(cl->hdr.head));
  97         cur_vars = NULL;
  98
  99         blob_buf_init(&b, 0);
 100
 101         handler_ret = 1;
 102         json_script_abort(ctx);
 103 }
 104
 105 static void
 106 handle_add_header(struct json_script_ctx *ctx, struct blob_attr *data)
 107 {
 108         struct client *cl = cur_client;
 109         static struct blobmsg_policy policy[2] = {
 110                  { .type = BLOBMSG_TYPE_STRING },
 111                  { .type = BLOBMSG_TYPE_STRING },
 112         };
 113         struct blob_attr *tb[2];
 114
 115         blobmsg_parse_array(policy, ARRAY_SIZE(tb), tb, blobmsg_data(data), blobmsg_data_len(data));
 116         if (!tb[0] || !tb[1])
 117                 return;
 118
 119         blobmsg_add_string(&cl->hdr_response, blobmsg_get_string(tb[0]),
 120                            blobmsg_get_string(tb[1]));
 121 }
 122
 123 static void
 124 handle_command(struct json_script_ctx *ctx, const char *name,
 125                struct blob_attr *data, struct blob_attr *vars)
 126 {
 127         static const struct {
 128                 const char *name;
 129                 void (*func)(struct json_script_ctx *ctx, struct blob_attr *data);
 130         } cmds[] = {
 131                 { "redirect", handle_redirect },
 132                 { "rewrite", handle_set_uri },
 133                 { "add-header", handle_add_header },
 134         };
 135         int i;
 136
 137         for (i = 0; i < ARRAY_SIZE(cmds); i++) {
 138                 if (!strcmp(cmds[i].name, name)) {
 139                         cmds[i].func(ctx, data);
 140                         return;
 141                 }
 142         }
 143 }
 144
 145 static const char *
 146 handle_var(struct json_script_ctx *ctx, const char *name,
 147            struct blob_attr *vars)
 148 {
 149         struct client *cl = cur_client;
 150         struct env_var *cur;
 151         static struct path_info empty_path;
 152
 153         if (!cur_vars) {
 154                 struct path_info *p = uh_path_lookup(cl, *cur_url);
 155
 156                 if (!p)
 157                         p = &empty_path;
 158
 159                 cur_vars = uh_get_process_vars(cl, p);
 160         }
 161
 162         for (cur = cur_vars; cur->name; cur++) {
 163                 if (!strcmp(cur->name, name))
 164                         return cur->value;
 165         }
 166         return NULL;
 167 }
 168
 169 static void
 170 handler_init(void)
 171 {
 172         if (handler_ctx.handle_command)
 173                 return;
 174
 175         json_script_init(&handler_ctx);
 176         handler_ctx.handle_command = handle_command;
 177         handler_ctx.handle_var = handle_var;
 178 }
 179
 180 static bool set_handler(struct json_script_file **dest, struct blob_attr *data)
 181 {
 182         if (!data)
 183                 return true;
 184
 185         *dest = json_script_file_from_blobmsg(NULL, blobmsg_data(data), blobmsg_data_len(data));
 186         return *dest;
 187 }
 188
 189 int uh_handler_add(const char *file)
 190 {
 191         enum {
 192                 H_REQUEST,
 193                 H_FALLBACK,
 194                 __H_MAX,
 195         };
 196         struct blobmsg_policy policy[__H_MAX] = {
 197                 [H_REQUEST] = { "request", BLOBMSG_TYPE_ARRAY },
 198                 [H_FALLBACK] = { "fallback", BLOBMSG_TYPE_ARRAY },
 199         };
 200         struct blob_attr *tb[__H_MAX];
 201         struct handler *h;
 202
 203         handler_init();
 204         blob_buf_init(&b, 0);
 205
 206         if (!blobmsg_add_json_from_file(&b, file))
 207                 return -1;
 208
 209         blobmsg_parse(policy, __H_MAX, tb, blob_data(b.head), blob_len(b.head));
 210         if (!tb[H_REQUEST] && !tb[H_FALLBACK])
 211                 return -1;
 212
 213         h = calloc(1, sizeof(*h));
 214         if (!set_handler(&h->request, tb[H_REQUEST]) ||
 215             !set_handler(&h->fallback, tb[H_FALLBACK])) {
 216                 free(h->request);
 217                 free(h->fallback);
 218                 free(h);
 219                 return -1;
 220         }
 221
 222         list_add_tail(&h->list, &handlers);
 223         return 0;
 224 }
 225
 226 int uh_handler_run(struct client *cl, char **url, bool fallback)
 227 {
 228         struct json_script_file *f;
 229         struct handler *h;
 230
 231         cur_client = cl;
 232         cur_url = url;
 233         cur_vars = NULL;
 234
 235         handler_ret = 0;
 236
 237         list_for_each_entry(h, &handlers, list) {
 238                 f = fallback ? h->fallback : h->request;
 239                 if (!f)
 240                         continue;
 241
 242                 blob_buf_init(&b, 0);
 243                 json_script_run_file(&handler_ctx, f, b.head);
 244                 if (handler_ctx.abort)
 245                         break;
 246         }
 247
 248         return handler_ret;
 249 }