src/util.c

   1 /*
   2  * Copyright (c) 2014 Ian Sutton <ian@kremlin.cc>
   3  *
   4  * Permission to use, copy, modify, and distribute this software for any
   5  * purpose with or without fee is hereby granted, provided that the above
   6  * copyright notice and this permission notice appear in all copies.
   7  *
   8  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
   9  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
  10  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
  11  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
  12  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
  13  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
  14  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  15  */
  16
  17 #include <unistd.h>
  18 #include <limits.h>
  19 #include <string.h>
  20
  21 #include <glib/gprintf.h>
  22 #include <glib-unix.h>
  23 #include <polkit/polkit.h>
  24
  25 #include "util.h"
  26
  27 const gint MAX_TOKENS = 20;
  28
  29 /* return must be g_free()'d */
  30 gchar *get_file_sha256(const gchar *path) {
  31
  32     gchar *checksum;
  33     GMappedFile *file;
  34     GBytes *data;
  35     GError *err = NULL;
  36
  37     file = g_mapped_file_new(path, FALSE, &err);
  38
  39     if(file) {
  40
  41         data = g_mapped_file_get_bytes(file);
  42         g_mapped_file_unref(file);
  43         checksum = g_compute_checksum_for_bytes(G_CHECKSUM_SHA256, data);
  44         return checksum;
  45     } else
  46         return NULL;
  47 }
  48
  49 /* return must be g_free()'d */
  50 gchar *config_get(const gchar *path, gchar *key) {
  51
  52     gchar  *content, **split_content, *cur, **cur_split, *ret;
  53     GError *err;
  54     int incr = 0;
  55     gboolean breaker = TRUE;
  56
  57     ret = (gchar *) g_malloc0(4096);
  58
  59     if(!g_file_get_contents(path, &content, NULL, &err))
  60         return NULL;
  61
  62     split_content = g_strsplit(content, "\n", MAX_TOKENS);
  63
  64     while(breaker && (cur = split_content[incr]) && (cur_split = g_strsplit(cur, "=", 2))) {
  65
  66         if(!g_strcmp0(key, cur_split[0])) {
  67
  68             g_strlcpy(ret, cur_split[1], 2048);
  69             breaker = FALSE;
  70         }
  71
  72         incr++;
  73         g_strfreev(cur_split);
  74     }
  75
  76     if(split_content)
  77         g_strfreev(split_content);
  78     if(content)
  79         g_free(content);
  80
  81     return (ret ? ret : NULL);
  82 }
  83
  84 gboolean config_set(const gchar *path, gchar *key, gchar *value) {
  85
  86     gchar  *content, **split_content, *cur, **cur_split, *rewrite;
  87     GError *err_set, *err_get;
  88     gboolean ret = FALSE;
  89     int incr = 0;
  90     gboolean breaker = TRUE;
  91
  92     err_get = err_set = NULL;
  93
  94     if(!g_file_get_contents(path, &content, NULL, &err_get))
  95         return FALSE;
  96
  97     split_content = g_strsplit(content, "\n", MAX_TOKENS);
  98
  99     while(breaker && (cur = split_content[incr]) && (cur_split = g_strsplit(cur, "=", 2))) {
 100
 101         if(!g_strcmp0(key, cur_split[0])) {
 102
 103             cur_split[1] = value;
 104             split_content[incr] = g_strjoinv("=", cur_split);
 105             ret = TRUE;
 106             breaker = FALSE;
 107         }
 108
 109         incr++;
 110     }
 111
 112     if(ret) {
 113
 114         rewrite = g_strjoinv("\n", split_content);
 115         ret = g_file_set_contents(path, rewrite, -1, &err_set);
 116         g_free(rewrite);
 117     }
 118
 119     if(cur_split)
 120         g_strfreev(cur_split);
 121     if(split_content)
 122         g_strfreev(split_content);
 123     if(content)
 124         g_free(content);
 125
 126     return ret;
 127 }
 128
 129 static gboolean is_valid_action(GList *action_list, const gchar *action) {
 130
 131     PolkitActionDescription *action_descr;
 132     const gchar *action_descr_id;
 133     GList *cur;
 134     gboolean ret;
 135
 136     ret = FALSE;
 137     cur = g_list_first(action_list);
 138
 139     while(cur && (action_descr = ((PolkitActionDescription *)(cur->data))) && (action_descr_id = polkit_action_description_get_action_id(action_descr))) {
 140
 141         if(!g_strcmp0(action, action_descr_id)) {
 142             ret = TRUE;
 143             break;
 144         }
 145
 146         cur = cur->next;
 147     }
 148
 149     g_list_free(action_list);
 150
 151     return ret;
 152 }
 153
 154 check_auth_result polkit_try_auth(const gchar *bus, const gchar *action, gboolean prompt) {
 155
 156     GList           *valid_actions;
 157     PolkitAuthority *auth;
 158     PolkitSubject   *subj;
 159     PolkitAuthorizationResult *result;
 160     PolkitCheckAuthorizationFlags prompt_flag;
 161     gboolean authorized, challenge;
 162
 163     auth  = NULL;
 164     subj  = NULL;
 165     result = NULL;
 166     valid_actions = NULL;
 167     authorized = challenge = FALSE;
 168     prompt_flag = prompt ? POLKIT_CHECK_AUTHORIZATION_FLAGS_ALLOW_USER_INTERACTION : POLKIT_CHECK_AUTHORIZATION_FLAGS_NONE;
 169
 170     auth = polkit_authority_get_sync(NULL, NULL); /* TODO timeout for this */
 171     subj = polkit_system_bus_name_new(bus);
 172     valid_actions = polkit_authority_enumerate_actions_sync(auth, NULL, NULL);
 173
 174    if(!auth || !valid_actions)
 175         return ERROR_GENERIC; /* extremely unlikely */
 176     else if(!subj)
 177         return ERROR_BADBUS;
 178     else if(!is_valid_action(valid_actions, action))
 179         return ERROR_BADACTION;
 180
 181    if(!(result = polkit_authority_check_authorization_sync(auth, subj, action, NULL, prompt_flag, NULL, NULL)))
 182         return ERROR_GENERIC; /* TODO pass, check gerror and return more relevant error */
 183
 184     authorized = polkit_authorization_result_get_is_authorized(result);
 185     challenge = polkit_authorization_result_get_is_challenge(result);
 186
 187     /* free()'s before return */
 188     if(auth)
 189         g_object_unref(auth);
 190     if(subj)
 191         g_object_unref(subj);
 192     if(result)
 193         g_object_unref(result);
 194
 195     if(authorized) {
 196
 197         if(challenge)
 198             return AUTHORIZED_BY_PROMPT;
 199
 200         return AUTHORIZED_NATIVELY;
 201
 202     } else if(challenge)
 203         return UNAUTHORIZED_FAILED_PROMPT;
 204
 205     return UNAUTHORIZED_NATIVELY;
 206 }