Commit c77b37a319fc698a43cdde6568d83d251a31753b
Factor out recursive CNAME lookups
Prevent infinite recursion using a stack argumentcel committed on 11/26/2016, 5:42:33 PM
Parent: c384b4a399e23b0210261e731e0ca78d6c84983f
Files changed
| lib/query.js | changed |
| lib/query.js | ||
|---|---|---|
| @@ -173,8 +173,60 @@ | ||
| 173 | 173 … | }); |
| 174 | 174 … | }; |
| 175 | 175 … | |
| 176 | 176 … | Query.query = function (sbot, question, cb) { |
| 177 … | + Query.queryRecursive(sbot, question, [], cb) | |
| 178 … | +} | |
| 179 … | + | |
| 180 … | +// recursive query | |
| 181 … | +Query.queryRecursive = function (sbot, question, stack, cb) { | |
| 182 … | + var result = { | |
| 183 … | + answers: [], | |
| 184 … | + authorities: [], | |
| 185 … | + additionals: [], | |
| 186 … | + expires: Date.now() + 60*60e3, | |
| 187 … | + }; | |
| 188 … | + | |
| 189 … | + // avoid infinite recursion | |
| 190 … | + if (stack.some(function (q) { | |
| 191 … | + return isRecordEqual(q, question); | |
| 192 … | + })) { | |
| 193 … | + return cb(null, result) | |
| 194 … | + } | |
| 195 … | + | |
| 196 … | + var waiting = 1; | |
| 197 … | + Query.querySingle(sbot, question, next); | |
| 198 … | + | |
| 199 … | + function next(err, res) { | |
| 200 … | + if (err) return waiting = 0, cb(err); | |
| 201 … | + | |
| 202 … | + merge(result.additionals, res.additionals); | |
| 203 … | + merge(result.answers, res.answers); | |
| 204 … | + merge(result.authorities, res.authorities); | |
| 205 … | + if (res.expires < result.expires) result.expires = res.expires; | |
| 206 … | + | |
| 207 … | + // recurse on CNAMEs | |
| 208 … | + if (question.type !== 'CNAME') { | |
| 209 … | + var stack2 = stack.concat(question) | |
| 210 … | + res.answers.filter(function (answer) { | |
| 211 … | + return answer.type === 'CNAME'; | |
| 212 … | + }).map(function (record) { | |
| 213 … | + return { | |
| 214 … | + class: question.class, | |
| 215 … | + type: question.type, | |
| 216 … | + name: record.data.replace(/\.$/, '') | |
| 217 … | + } | |
| 218 … | + }).forEach(function (q) { | |
| 219 … | + waiting++ | |
| 220 … | + Query.queryRecursive(sbot, q, stack2, next) | |
| 221 … | + }); | |
| 222 … | + } | |
| 223 … | + | |
| 224 … | + if (!--waiting) cb(null, result); | |
| 225 … | + } | |
| 226 … | +} | |
| 227 … | + | |
| 228 … | +Query.querySingle = function (sbot, question, cb) { | |
| 177 | 229 … | // look up records that match a question, including wildcard records |
| 178 | 230 … | // and zone authority records |
| 179 | 231 … | var authorityDomains = expandName(question.name); |
| 180 | 232 … | var wildcardDomains = expandName(question.name, '*'); |
| @@ -230,30 +282,7 @@ | ||
| 230 | 282 … | } |
| 231 | 283 … | }); |
| 232 | 284 … | result.expires = Date.now() + ttl * 60e3; |
| 233 | 285 … | result.additionals = []; |
| 234 | - // resolve cnames with another query | |
| 235 | - if (question.type !== 'CNAME') { | |
| 236 | - var cnames = result.answers.filter(function (answer) { | |
| 237 | - return answer.type === 'CNAME'; | |
| 238 | - }); | |
| 239 | - var waiting = cnames.length; | |
| 240 | - if (waiting > 0) { | |
| 241 | - return cnames.forEach(function (record) { | |
| 242 | - Query.query(sbot, { | |
| 243 | - class: question.class, | |
| 244 | - type: question.type, | |
| 245 | - name: record.data.replace(/\.$/, '') | |
| 246 | - }, next); | |
| 247 | - }) | |
| 248 | - function next(err, res) { | |
| 249 | - if (err) return waiting = 0, cb(err) | |
| 250 | - merge(result.additionals, res.additionals); | |
| 251 | - merge(result.answers, res.answers); | |
| 252 | - merge(result.authorities, res.authorities); | |
| 253 | - if (!--waiting) cb(err, result); | |
| 254 | - } | |
| 255 | - } | |
| 256 | - } | |
| 257 | 286 … | cb(null, result); |
| 258 | 287 … | })); |
| 259 | 288 … | }; |
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