file.c

   1 /*
   2  * luci-rpcd - LuCI UBUS RPC server
   3  *
   4  *   Copyright (C) 2013 Jo-Philipp Wich <jow@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 <fcntl.h>
  20 #include <errno.h>
  21 #include <unistd.h>
  22 #include <dirent.h>
  23 #include <sys/stat.h>
  24
  25 #include "file.h"
  26
  27 static struct blob_buf buf;
  28
  29 enum {
  30         RPC_F_PATH,
  31         RPC_F_DATA,
  32         __RPC_F_MAX,
  33 };
  34
  35 static const struct blobmsg_policy file_policy[__RPC_F_MAX] = {
  36         [RPC_F_PATH] = { .name = "path", .type = BLOBMSG_TYPE_STRING },
  37         [RPC_F_DATA] = { .name = "data", .type = BLOBMSG_TYPE_STRING },
  38 };
  39
  40 static const char *d_types[] = {
  41         [DT_BLK]     = "block",
  42         [DT_CHR]     = "char",
  43         [DT_DIR]     = "directory",
  44         [DT_FIFO]    = "fifo",
  45         [DT_LNK]     = "symlink",
  46         [DT_REG]     = "file",
  47         [DT_SOCK]    = "socket",
  48         [DT_UNKNOWN] = "unknown",
  49 };
  50
  51
  52 static int
  53 rpc_errno_status(void)
  54 {
  55         switch (errno)
  56         {
  57         case EACCES:
  58                 return UBUS_STATUS_PERMISSION_DENIED;
  59
  60         case ENOTDIR:
  61                 return UBUS_STATUS_INVALID_ARGUMENT;
  62
  63         case ENOENT:
  64                 return UBUS_STATUS_NOT_FOUND;
  65
  66         case EINVAL:
  67                 return UBUS_STATUS_INVALID_ARGUMENT;
  68
  69         default:
  70                 return UBUS_STATUS_UNKNOWN_ERROR;
  71         }
  72 }
  73
  74 static struct blob_attr **
  75 rpc_check_path(struct blob_attr *msg, char **path, struct stat *s)
  76 {
  77         static struct blob_attr *tb[__RPC_F_MAX];
  78
  79         blobmsg_parse(file_policy, __RPC_F_MAX, tb, blob_data(msg), blob_len(msg));
  80
  81         if (!tb[RPC_F_PATH])
  82         {
  83                 errno = EINVAL;
  84                 return NULL;
  85         }
  86
  87         *path = blobmsg_data(tb[RPC_F_PATH]);
  88
  89         if (stat(*path, s))
  90                 return NULL;
  91
  92         return tb;
  93 }
  94
  95 static int
  96 rpc_handle_read(struct ubus_context *ctx, struct ubus_object *obj,
  97                 struct ubus_request_data *req, const char *method,
  98                 struct blob_attr *msg)
  99 {
 100         int fd, rlen;
 101         char *path;
 102         char buffer[RPC_FILE_MAX_SIZE];
 103         struct stat s;
 104
 105         if (!rpc_check_path(msg, &path, &s))
 106                 return rpc_errno_status();
 107
 108         if (s.st_size >= RPC_FILE_MAX_SIZE)
 109                 return UBUS_STATUS_NOT_SUPPORTED;
 110
 111         if ((fd = open(path, O_RDONLY)) < 0)
 112                 return rpc_errno_status();
 113
 114         if ((rlen = read(fd, buffer, RPC_FILE_MAX_SIZE-1)) > 0)
 115                 buffer[rlen] = 0;
 116
 117         close(fd);
 118
 119         if (rlen <= 0)
 120                 return UBUS_STATUS_NO_DATA;
 121
 122         blob_buf_init(&buf, 0);
 123         blobmsg_add_string(&buf, "data", buffer);
 124         ubus_send_reply(ctx, req, buf.head);
 125
 126         return 0;
 127 }
 128
 129 static int
 130 rpc_handle_write(struct ubus_context *ctx, struct ubus_object *obj,
 131                  struct ubus_request_data *req, const char *method,
 132                  struct blob_attr *msg)
 133 {
 134         int fd, rv;
 135         char *path;
 136         struct stat s;
 137         struct blob_attr **tb;
 138
 139         if (!(tb = rpc_check_path(msg, &path, &s)))
 140                 return rpc_errno_status();
 141
 142         if (!tb[RPC_F_DATA])
 143                 return UBUS_STATUS_INVALID_ARGUMENT;
 144
 145         if ((fd = open(path, O_WRONLY)) < 0)
 146                 return rpc_errno_status();
 147
 148         rv = write(fd, blobmsg_data(tb[RPC_F_DATA]), blobmsg_data_len(tb[RPC_F_DATA]));
 149
 150         close(fd);
 151
 152         if (rv <= 0)
 153                 return UBUS_STATUS_NO_DATA;
 154
 155         return 0;
 156 }
 157
 158 static int
 159 rpc_handle_list(struct ubus_context *ctx, struct ubus_object *obj,
 160                 struct ubus_request_data *req, const char *method,
 161                 struct blob_attr *msg)
 162 {
 163         DIR *fd;
 164         void *c, *d;
 165         char *path;
 166         struct stat s;
 167         struct dirent *e;
 168
 169         if (!rpc_check_path(msg, &path, &s))
 170                 return rpc_errno_status();
 171
 172         if ((fd = opendir(path)) == NULL)
 173                 return rpc_errno_status();
 174
 175         blob_buf_init(&buf, 0);
 176         c = blobmsg_open_array(&buf, "entries");
 177
 178         while ((e = readdir(fd)) != NULL)
 179         {
 180                 if (!strcmp(e->d_name, ".") || !strcmp(e->d_name, ".."))
 181                         continue;
 182
 183                 d = blobmsg_open_table(&buf, NULL);
 184                 blobmsg_add_string(&buf, "name", e->d_name);
 185                 blobmsg_add_string(&buf, "type", d_types[e->d_type]);
 186                 blobmsg_close_table(&buf, d);
 187         }
 188
 189         blobmsg_close_array(&buf, c);
 190         ubus_send_reply(ctx, req, buf.head);
 191
 192         return 0;
 193 }
 194
 195 static int
 196 rpc_handle_stat(struct ubus_context *ctx, struct ubus_object *obj,
 197                 struct ubus_request_data *req, const char *method,
 198                 struct blob_attr *msg)
 199 {
 200         int type;
 201         char *path;
 202         struct stat s;
 203
 204         if (!rpc_check_path(msg, &path, &s))
 205                 return rpc_errno_status();
 206
 207         blob_buf_init(&buf, 0);
 208
 209         type = S_ISREG(s.st_mode) ? DT_REG :
 210                 S_ISDIR(s.st_mode) ? DT_DIR :
 211                          S_ISCHR(s.st_mode) ? DT_CHR :
 212                           S_ISBLK(s.st_mode) ? DT_BLK :
 213                            S_ISFIFO(s.st_mode) ? DT_FIFO :
 214                             S_ISLNK(s.st_mode) ? DT_LNK :
 215                                  S_ISSOCK(s.st_mode) ? DT_SOCK :
 216                                   DT_UNKNOWN;
 217
 218         blobmsg_add_string(&buf, "path", path);
 219         blobmsg_add_string(&buf, "type", d_types[type]);
 220         blobmsg_add_u32(&buf, "size",  s.st_size);
 221         blobmsg_add_u32(&buf, "mode",  s.st_mode);
 222         blobmsg_add_u32(&buf, "atime", s.st_atime);
 223         blobmsg_add_u32(&buf, "mtime", s.st_mtime);
 224         blobmsg_add_u32(&buf, "ctime", s.st_ctime);
 225         blobmsg_add_u32(&buf, "inode", s.st_ino);
 226         blobmsg_add_u32(&buf, "uid",   s.st_uid);
 227         blobmsg_add_u32(&buf, "gid",   s.st_gid);
 228
 229         ubus_send_reply(ctx, req, buf.head);
 230
 231         return 0;
 232 }
 233
 234
 235 int rpc_file_api_init(struct ubus_context *ctx)
 236 {
 237         static const struct ubus_method file_methods[] = {
 238                 UBUS_METHOD("read",    rpc_handle_read,  file_policy),
 239                 UBUS_METHOD("write",   rpc_handle_write, file_policy),
 240                 UBUS_METHOD("list",    rpc_handle_list,  file_policy),
 241                 UBUS_METHOD("stat",    rpc_handle_stat,  file_policy),
 242         };
 243
 244         static struct ubus_object_type file_type =
 245                 UBUS_OBJECT_TYPE("luci-rpc-file", file_methods);
 246
 247         static struct ubus_object obj = {
 248                 .name = "file",
 249                 .type = &file_type,
 250                 .methods = file_methods,
 251                 .n_methods = ARRAY_SIZE(file_methods),
 252         };
 253
 254         return ubus_add_object(ctx, &obj);
 255 }