diff options
Diffstat (limited to 'indra/llmessage/message.h')
| -rw-r--r-- | indra/llmessage/message.h | 198 |
1 files changed, 158 insertions, 40 deletions
diff --git a/indra/llmessage/message.h b/indra/llmessage/message.h index f6c5d9e228..e25a9ea7ef 100644 --- a/indra/llmessage/message.h +++ b/indra/llmessage/message.h @@ -35,10 +35,6 @@ #include <netinet/in.h> #endif -#if LL_SOLARIS -#include <netinet/in.h> -#endif - #if LL_WINDOWS #include "winsock2.h" // htons etc. #endif @@ -61,6 +57,8 @@ #include "llstoredmessage.h" #include "boost/function.hpp" #include "llpounceable.h" +#include "llcoros.h" +#include LLCOROS_MUTEX_HEADER const U32 MESSAGE_MAX_STRINGS_LENGTH = 64; const U32 MESSAGE_NUMBER_OF_HASH_BUCKETS = 8192; @@ -199,6 +197,91 @@ public: virtual void complete(const LLHost& host, const LLUUID& agent) const = 0; }; +/** + * SL-12204: We've observed crashes when consumer code sets + * LLMessageSystem::mMessageReader, assuming that all subsequent processing of + * the current message will use the same mMessageReader value -- only to have + * a different coroutine sneak in and replace mMessageReader before + * completion. This is a limitation of sharing a stateful global resource for + * message parsing; instead code receiving a new message should instantiate a + * (trivially constructed) local message parser and use that. + * + * Until then, when one coroutine sets a particular LLMessageReader subclass + * as the current message reader, ensure that no other coroutine can replace + * it until the first coroutine has finished with its message. + * + * This is achieved with two helper classes. LLMessageSystem::mMessageReader + * is now an LLMessageReaderPointer instance, which can efficiently compare or + * dereference its contained LLMessageReader* but which cannot be directly + * assigned. To change the value of LLMessageReaderPointer, you must + * instantiate LockMessageReader with the LLMessageReader* you wish to make + * current. mMessageReader will have that value for the lifetime of the + * LockMessageReader instance, then revert to nullptr. Moreover, as its name + * implies, LockMessageReader locks the mutex in LLMessageReaderPointer so + * that any other coroutine instantiating LockMessageReader will block until + * the first coroutine has destroyed its instance. + */ +class LLMessageReaderPointer +{ +public: + LLMessageReaderPointer(): mPtr(nullptr) {} + // It is essential that comparison and dereferencing must be fast, which + // is why we don't check for nullptr when dereferencing. + LLMessageReader* operator->() const { return mPtr; } + bool operator==(const LLMessageReader* other) const { return mPtr == other; } + bool operator!=(const LLMessageReader* other) const { return ! (*this == other); } +private: + // Only LockMessageReader can set mPtr. + friend class LockMessageReader; + LLMessageReader* mPtr; + LLCoros::Mutex mMutex; +}; + +/** + * To set mMessageReader to nullptr: + * + * @code + * // use an anonymous instance that is destroyed immediately + * LockMessageReader(gMessageSystem->mMessageReader, nullptr); + * @endcode + * + * Why do we still require going through LockMessageReader at all? Because it + * would be Bad if any coroutine set mMessageReader to nullptr while another + * coroutine was still parsing a message. + */ +class LockMessageReader +{ +public: + LockMessageReader(LLMessageReaderPointer& var, LLMessageReader* instance): + mVar(var.mPtr), + mLock(var.mMutex) + { + mVar = instance; + } + // Some compilers reportedly fail to suppress generating implicit copy + // operations even though we have a move-only LockType data member. + LockMessageReader(const LockMessageReader&) = delete; + LockMessageReader& operator=(const LockMessageReader&) = delete; + ~LockMessageReader() + { + mVar = nullptr; + } +private: + // capture a reference to LLMessageReaderPointer::mPtr + decltype(LLMessageReaderPointer::mPtr)& mVar; + // while holding a lock on LLMessageReaderPointer::mMutex + LLCoros::LockType mLock; +}; + +/** + * LockMessageReader is great as long as you only need mMessageReader locked + * during a single LLMessageSystem function call. However, empirically the + * sequence from checkAllMessages() through processAcks() need mMessageReader + * locked to LLTemplateMessageReader. Enforce that by making them require an + * instance of LockMessageChecker. + */ +class LockMessageChecker; + class LLMessageSystem : public LLMessageSenderInterface { private: @@ -331,8 +414,8 @@ public: bool addCircuitCode(U32 code, const LLUUID& session_id); BOOL poll(F32 seconds); // Number of seconds that we want to block waiting for data, returns if data was received - BOOL checkMessages( S64 frame_count = 0 ); - void processAcks(F32 collect_time = 0.f); + BOOL checkMessages(LockMessageChecker&, S64 frame_count = 0 ); + void processAcks(LockMessageChecker&, F32 collect_time = 0.f); BOOL isMessageFast(const char *msg); BOOL isMessage(const char *msg) @@ -730,7 +813,7 @@ public: const LLSD& data); // Check UDP messages and pump http_pump to receive HTTP messages. - bool checkAllMessages(S64 frame_count, LLPumpIO* http_pump); + bool checkAllMessages(LockMessageChecker&, S64 frame_count, LLPumpIO* http_pump); // Moved to allow access from LLTemplateMessageDispatcher void clearReceiveState(); @@ -817,12 +900,13 @@ private: LLMessageBuilder* mMessageBuilder; LLTemplateMessageBuilder* mTemplateMessageBuilder; LLSDMessageBuilder* mLLSDMessageBuilder; - LLMessageReader* mMessageReader; + LLMessageReaderPointer mMessageReader; LLTemplateMessageReader* mTemplateMessageReader; LLSDMessageReader* mLLSDMessageReader; friend class LLMessageHandlerBridge; - + friend class LockMessageChecker; + bool callHandler(const char *name, bool trustedSource, LLMessageSystem* msg); @@ -835,6 +919,40 @@ private: // external hook into messaging system extern LLPounceable<LLMessageSystem*, LLPounceableStatic> gMessageSystem; +// Implementation of LockMessageChecker depends on definition of +// LLMessageSystem, hence must follow it. +class LockMessageChecker: public LockMessageReader +{ +public: + LockMessageChecker(LLMessageSystem* msgsystem); + + // For convenience, provide forwarding wrappers so you can call (e.g.) + // checkAllMessages() on your LockMessageChecker instance instead of + // passing the instance to LLMessageSystem::checkAllMessages(). Use + // perfect forwarding to avoid having to maintain these wrappers in sync + // with the target methods. + template <typename... ARGS> + bool checkAllMessages(ARGS&&... args) + { + return mMessageSystem->checkAllMessages(*this, std::forward<ARGS>(args)...); + } + + template <typename... ARGS> + bool checkMessages(ARGS&&... args) + { + return mMessageSystem->checkMessages(*this, std::forward<ARGS>(args)...); + } + + template <typename... ARGS> + void processAcks(ARGS&&... args) + { + return mMessageSystem->processAcks(*this, std::forward<ARGS>(args)...); + } + +private: + LLMessageSystem* mMessageSystem; +}; + // Must specific overall system version, which is used to determine // if a patch is available in the message template checksum verification. // Return true if able to initialize system. @@ -860,10 +978,10 @@ void null_message_callback(LLMessageSystem *msg, void **data); // #if !defined( LL_BIG_ENDIAN ) && !defined( LL_LITTLE_ENDIAN ) -#error Unknown endianness for htonmemcpy. Did you miss a common include? +#error Unknown endianness for htolememcpy. Did you miss a common include? #endif -static inline void *htonmemcpy(void *vs, const void *vct, EMsgVariableType type, size_t n) +static inline void *htolememcpy(void *vs, const void *vct, EMsgVariableType type, size_t n) { char *s = (char *)vs; const char *ct = (const char *)vct; @@ -886,7 +1004,7 @@ static inline void *htonmemcpy(void *vs, const void *vct, EMsgVariableType type, case MVT_S16: if (n != 2) { - LL_ERRS() << "Size argument passed to htonmemcpy doesn't match swizzle type size" << LL_ENDL; + LL_ERRS() << "Size argument passed to htolememcpy doesn't match swizzle type size" << LL_ENDL; } #ifdef LL_BIG_ENDIAN *(s + 1) = *(ct); @@ -901,7 +1019,7 @@ static inline void *htonmemcpy(void *vs, const void *vct, EMsgVariableType type, case MVT_F32: if (n != 4) { - LL_ERRS() << "Size argument passed to htonmemcpy doesn't match swizzle type size" << LL_ENDL; + LL_ERRS() << "Size argument passed to htolememcpy doesn't match swizzle type size" << LL_ENDL; } #ifdef LL_BIG_ENDIAN *(s + 3) = *(ct); @@ -918,7 +1036,7 @@ static inline void *htonmemcpy(void *vs, const void *vct, EMsgVariableType type, case MVT_F64: if (n != 8) { - LL_ERRS() << "Size argument passed to htonmemcpy doesn't match swizzle type size" << LL_ENDL; + LL_ERRS() << "Size argument passed to htolememcpy doesn't match swizzle type size" << LL_ENDL; } #ifdef LL_BIG_ENDIAN *(s + 7) = *(ct); @@ -938,12 +1056,12 @@ static inline void *htonmemcpy(void *vs, const void *vct, EMsgVariableType type, case MVT_LLQuaternion: // We only send x, y, z and infer w (we set x, y, z to ensure that w >= 0) if (n != 12) { - LL_ERRS() << "Size argument passed to htonmemcpy doesn't match swizzle type size" << LL_ENDL; + LL_ERRS() << "Size argument passed to htolememcpy doesn't match swizzle type size" << LL_ENDL; } #ifdef LL_BIG_ENDIAN - htonmemcpy(s + 8, ct + 8, MVT_F32, 4); - htonmemcpy(s + 4, ct + 4, MVT_F32, 4); - return(htonmemcpy(s, ct, MVT_F32, 4)); + htolememcpy(s + 8, ct + 8, MVT_F32, 4); + htolememcpy(s + 4, ct + 4, MVT_F32, 4); + return(htolememcpy(s, ct, MVT_F32, 4)); #else return(memcpy(s,ct,n)); /* Flawfinder: ignore */ #endif @@ -951,12 +1069,12 @@ static inline void *htonmemcpy(void *vs, const void *vct, EMsgVariableType type, case MVT_LLVector3d: if (n != 24) { - LL_ERRS() << "Size argument passed to htonmemcpy doesn't match swizzle type size" << LL_ENDL; + LL_ERRS() << "Size argument passed to htolememcpy doesn't match swizzle type size" << LL_ENDL; } #ifdef LL_BIG_ENDIAN - htonmemcpy(s + 16, ct + 16, MVT_F64, 8); - htonmemcpy(s + 8, ct + 8, MVT_F64, 8); - return(htonmemcpy(s, ct, MVT_F64, 8)); + htolememcpy(s + 16, ct + 16, MVT_F64, 8); + htolememcpy(s + 8, ct + 8, MVT_F64, 8); + return(htolememcpy(s, ct, MVT_F64, 8)); #else return(memcpy(s,ct,n)); /* Flawfinder: ignore */ #endif @@ -964,13 +1082,13 @@ static inline void *htonmemcpy(void *vs, const void *vct, EMsgVariableType type, case MVT_LLVector4: if (n != 16) { - LL_ERRS() << "Size argument passed to htonmemcpy doesn't match swizzle type size" << LL_ENDL; + LL_ERRS() << "Size argument passed to htolememcpy doesn't match swizzle type size" << LL_ENDL; } #ifdef LL_BIG_ENDIAN - htonmemcpy(s + 12, ct + 12, MVT_F32, 4); - htonmemcpy(s + 8, ct + 8, MVT_F32, 4); - htonmemcpy(s + 4, ct + 4, MVT_F32, 4); - return(htonmemcpy(s, ct, MVT_F32, 4)); + htolememcpy(s + 12, ct + 12, MVT_F32, 4); + htolememcpy(s + 8, ct + 8, MVT_F32, 4); + htolememcpy(s + 4, ct + 4, MVT_F32, 4); + return(htolememcpy(s, ct, MVT_F32, 4)); #else return(memcpy(s,ct,n)); /* Flawfinder: ignore */ #endif @@ -978,12 +1096,12 @@ static inline void *htonmemcpy(void *vs, const void *vct, EMsgVariableType type, case MVT_U16Vec3: if (n != 6) { - LL_ERRS() << "Size argument passed to htonmemcpy doesn't match swizzle type size" << LL_ENDL; + LL_ERRS() << "Size argument passed to htolememcpy doesn't match swizzle type size" << LL_ENDL; } #ifdef LL_BIG_ENDIAN - htonmemcpy(s + 4, ct + 4, MVT_U16, 2); - htonmemcpy(s + 2, ct + 2, MVT_U16, 2); - return(htonmemcpy(s, ct, MVT_U16, 2)); + htolememcpy(s + 4, ct + 4, MVT_U16, 2); + htolememcpy(s + 2, ct + 2, MVT_U16, 2); + return(htolememcpy(s, ct, MVT_U16, 2)); #else return(memcpy(s,ct,n)); /* Flawfinder: ignore */ #endif @@ -991,13 +1109,13 @@ static inline void *htonmemcpy(void *vs, const void *vct, EMsgVariableType type, case MVT_U16Quat: if (n != 8) { - LL_ERRS() << "Size argument passed to htonmemcpy doesn't match swizzle type size" << LL_ENDL; + LL_ERRS() << "Size argument passed to htolememcpy doesn't match swizzle type size" << LL_ENDL; } #ifdef LL_BIG_ENDIAN - htonmemcpy(s + 6, ct + 6, MVT_U16, 2); - htonmemcpy(s + 4, ct + 4, MVT_U16, 2); - htonmemcpy(s + 2, ct + 2, MVT_U16, 2); - return(htonmemcpy(s, ct, MVT_U16, 2)); + htolememcpy(s + 6, ct + 6, MVT_U16, 2); + htolememcpy(s + 4, ct + 4, MVT_U16, 2); + htolememcpy(s + 2, ct + 2, MVT_U16, 2); + return(htolememcpy(s, ct, MVT_U16, 2)); #else return(memcpy(s,ct,n)); /* Flawfinder: ignore */ #endif @@ -1005,15 +1123,15 @@ static inline void *htonmemcpy(void *vs, const void *vct, EMsgVariableType type, case MVT_S16Array: if (n % 2) { - LL_ERRS() << "Size argument passed to htonmemcpy doesn't match swizzle type size" << LL_ENDL; + LL_ERRS() << "Size argument passed to htolememcpy doesn't match swizzle type size" << LL_ENDL; } #ifdef LL_BIG_ENDIAN length = n % 2; for (i = 1; i < length; i++) { - htonmemcpy(s + i*2, ct + i*2, MVT_S16, 2); + htolememcpy(s + i*2, ct + i*2, MVT_S16, 2); } - return(htonmemcpy(s, ct, MVT_S16, 2)); + return(htolememcpy(s, ct, MVT_S16, 2)); #else return(memcpy(s,ct,n)); #endif @@ -1025,7 +1143,7 @@ static inline void *htonmemcpy(void *vs, const void *vct, EMsgVariableType type, inline void *ntohmemcpy(void *s, const void *ct, EMsgVariableType type, size_t n) { - return(htonmemcpy(s,ct,type, n)); + return(htolememcpy(s,ct,type, n)); } inline const LLHost& LLMessageSystem::getReceivingInterface() const {return mLastReceivingIF;} |