1 #include "first.h" 2 3 #include "base.h" 4 #include "array.h" 5 #include "buffer.h" 6 #include "log.h" 7 8 #include "plugin.h" 9 10 #include <stdlib.h> 11 #include <string.h> 12 13 typedef struct { 14 const array *alias; 15 } plugin_config; 16 17 typedef struct { 18 PLUGIN_DATA; 19 plugin_config defaults; 20 plugin_config conf; 21 } plugin_data; 22 23 INIT_FUNC(mod_alias_init) { 24 return calloc(1, sizeof(plugin_data)); 25 } 26 27 static void mod_alias_merge_config_cpv(plugin_config * const pconf, const config_plugin_value_t * const cpv) { 28 switch (cpv->k_id) { /* index into static config_plugin_keys_t cpk[] */ 29 case 0: /* alias.url */ 30 pconf->alias = cpv->v.a; 31 break; 32 default:/* should not happen */ 33 return; 34 } 35 } 36 37 static void mod_alias_merge_config(plugin_config * const pconf, const config_plugin_value_t *cpv) { 38 do { 39 mod_alias_merge_config_cpv(pconf, cpv); 40 } while ((++cpv)->k_id != -1); 41 } 42 43 static void mod_alias_patch_config(request_st * const r, plugin_data * const p) { 44 p->conf = p->defaults; /* copy small struct instead of memcpy() */ 45 /*memcpy(&p->conf, &p->defaults, sizeof(plugin_config));*/ 46 for (int i = 1, used = p->nconfig; i < used; ++i) { 47 if (config_check_cond(r, (uint32_t)p->cvlist[i].k_id)) 48 mod_alias_merge_config(&p->conf, p->cvlist + p->cvlist[i].v.u2[0]); 49 } 50 } 51 52 static int mod_alias_check_order(server * const srv, const array * const a) { 53 for (uint32_t j = 0; j < a->used; ++j) { 54 const buffer * const prefix = &a->sorted[j]->key; 55 const size_t plen = buffer_string_length(prefix); 56 for (uint32_t k = j + 1; k < a->used; ++k) { 57 const buffer * const key = &a->sorted[k]->key; 58 if (buffer_string_length(key) < plen) { 59 break; 60 } 61 if (memcmp(key->ptr, prefix->ptr, plen) != 0) { 62 break; 63 } 64 /* ok, they have same prefix. check position */ 65 const data_unset *dj = a->sorted[j]; 66 const data_unset *dk = a->sorted[k]; 67 const data_unset **data = (const data_unset **)a->data; 68 while (*data != dj && *data != dk) ++data; 69 if (*data == dj) { 70 log_error(srv->errh, __FILE__, __LINE__, 71 "url.alias: `%s' will never match as `%s' matched first", 72 key->ptr, prefix->ptr); 73 return 0; 74 } 75 } 76 } 77 return 1; 78 } 79 80 SETDEFAULTS_FUNC(mod_alias_set_defaults) { 81 static const config_plugin_keys_t cpk[] = { 82 { CONST_STR_LEN("alias.url"), 83 T_CONFIG_ARRAY_KVSTRING, 84 T_CONFIG_SCOPE_CONNECTION } 85 ,{ NULL, 0, 86 T_CONFIG_UNSET, 87 T_CONFIG_SCOPE_UNSET } 88 }; 89 90 plugin_data * const p = p_d; 91 if (!config_plugin_values_init(srv, p, cpk, "mod_alias")) 92 return HANDLER_ERROR; 93 94 /* process and validate config directives 95 * (init i to 0 if global context; to 1 to skip empty global context) */ 96 for (int i = !p->cvlist[0].v.u2[1]; i < p->nconfig; ++i) { 97 const config_plugin_value_t *cpv = p->cvlist + p->cvlist[i].v.u2[0]; 98 for (; -1 != cpv->k_id; ++cpv) { 99 switch (cpv->k_id) { 100 case 0: /* alias.url */ 101 if (cpv->v.a->used >= 2 && !mod_alias_check_order(srv,cpv->v.a)) 102 return HANDLER_ERROR; 103 break; 104 default:/* should not happen */ 105 break; 106 } 107 } 108 } 109 110 /* initialize p->defaults from global config context */ 111 if (p->nconfig > 0 && p->cvlist->v.u2[1]) { 112 const config_plugin_value_t *cpv = p->cvlist + p->cvlist->v.u2[0]; 113 if (-1 != cpv->k_id) 114 mod_alias_merge_config(&p->defaults, cpv); 115 } 116 117 return HANDLER_GO_ON; 118 } 119 120 PHYSICALPATH_FUNC(mod_alias_physical_handler) { 121 plugin_data *p = p_d; 122 char *uri_ptr; 123 size_t uri_len = buffer_string_length(&r->physical.path); 124 size_t basedir_len, alias_len; 125 data_string *ds; 126 127 if (0 == uri_len) return HANDLER_GO_ON; 128 129 mod_alias_patch_config(r, p); 130 if (NULL == p->conf.alias) return HANDLER_GO_ON; 131 132 /* do not include trailing slash on basedir */ 133 basedir_len = buffer_string_length(&r->physical.basedir); 134 if ('/' == r->physical.basedir.ptr[basedir_len-1]) --basedir_len; 135 uri_len -= basedir_len; 136 uri_ptr = r->physical.path.ptr + basedir_len; 137 138 ds = (!r->conf.force_lowercase_filenames) 139 ? (data_string *)array_match_key_prefix_klen(p->conf.alias, uri_ptr, uri_len) 140 : (data_string *)array_match_key_prefix_nc_klen(p->conf.alias, uri_ptr, uri_len); 141 if (NULL == ds) { return HANDLER_GO_ON; } 142 143 /* matched */ 144 145 /* check for path traversal in url-path following alias if key 146 * does not end in slash, but replacement value ends in slash */ 147 alias_len = buffer_string_length(&ds->key); 148 if (uri_ptr[alias_len] == '.') { 149 char *s = uri_ptr + alias_len + 1; 150 if (*s == '.') ++s; 151 if (*s == '/' || *s == '\0') { 152 size_t vlen = buffer_string_length(&ds->value); 153 if (0 != alias_len && ds->key.ptr[alias_len-1] != '/' 154 && 0 != vlen && ds->value.ptr[vlen-1] == '/') { 155 r->http_status = 403; 156 return HANDLER_FINISHED; 157 } 158 } 159 } 160 161 buffer * const tb = r->tmp_buf; 162 buffer_copy_buffer(&r->physical.basedir, &ds->value); 163 buffer_copy_buffer(tb, &ds->value); 164 buffer_append_string(tb, uri_ptr + alias_len); 165 buffer_copy_buffer(&r->physical.path, tb); 166 167 return HANDLER_GO_ON; 168 } 169 170 171 int mod_alias_plugin_init(plugin *p); 172 int mod_alias_plugin_init(plugin *p) { 173 p->version = LIGHTTPD_VERSION_ID; 174 p->name = "alias"; 175 176 p->init = mod_alias_init; 177 p->handle_physical= mod_alias_physical_handler; 178 p->set_defaults = mod_alias_set_defaults; 179 180 return 0; 181 } 182