Passive re-assembly of HTTP2 fragmented segments

A computer system of re-assembling fragmented Hypertext Transfer Protocol Version 2 (HTTP2) fragments comprising one or more processors, one or more computer-readable memories, one or more computer-readable tangible storage media, and program instructions stored on at least one of the one or more computer-readable tangible storage media for execution by at least one of the one or more processors via at least one of the one or more computer-readable memories, wherein the computer system is capable of performing a method comprising:

• in response to receiving a Secure Sockets Layer/Transport Layer Security (SSL/TLS) segment, querying for a Transmission Control Protocol (TCP) sequence number from a TCP sequence number hash table, wherein the TCP sequence number hash table comprises the TCP sequence number and an associated stream identifier, wherein the associated stream identifier identifies a first HTTP2 message segment, and wherein the TCP sequence number hash table is indexed by the TCP sequence number;
• in response to locating a matching TCP sequence number in the TCP sequence number hash table, extracting from the TCP sequence number hash table an associated stream identifier;
• using the associated stream identifier, extracting a HTTP2 stream identifier from a HTTP2 hash table, wherein the HTTP2 stream identifier matches the associated stream identifier;
• extracting from the HTTP2 hash table a HTTP2 buffer and a HTTP2 remaining length, wherein the HTTP2 buffer and the HTTP2 remaining length are associated with the HTTP2 stream identifier;
• based on a SSL/TLS segment length being less than the HTTP2 remaining length, starting fragmented re-assembly;
• and
• based on the SSL/TLS segment length being equal to the HTTP2 remaining length or greater than the HTTP2 remaining length, appending a SSL/TLS remaining length of data from the SSL/TLS segment to the HTTP2 buffer, and processing frame payload using the HTTP2 buffer.

A computer program product comprising a computer readable storage medium having program instructions embodied therewith, the program instructions executable by a processor of a computing device to cause the processor to perform operations comprising:

• in response to receiving a Secure Sockets Layer/Transport Layer Security (SSL/TLS) segment, querying for a Transmission Control Protocol (TCP) sequence number from a TCP sequence number hash table, wherein the TCP sequence number hash table comprises the TCP sequence number and the associated stream identifier, wherein the associated stream identifier identifies a first Hypertext Transfer Protocol Version 2 (HTTP2) message segment, and wherein the TCP sequence number hash table is indexed by the TCP sequence number;
• in response to locating a matching TCP sequence number in the TCP sequence number hash table, extracting from the TCP sequence number hash table the associated stream identifier;
• using the associated stream identifier, extracting the (HTTP2) stream identifier from a HTTP2 hash table, wherein the HTTP2 stream identifier matches the associated stream identifier;
• extracting from the HTTP2 hash table a HTTP2 buffer and a HTTP2 remaining length, wherein the HTTP2 buffer and the HTTP2 remaining length are associated with the HTTP2 stream identifier;
• based on a SSL/TLS segment length being less than the HTTP2 remaining length, starting fragmented re-assembly;
• and
• based on the SSL/TLS segment length being equal to the HTTP2 remaining length or greater than the HTTP2 remaining length, appending a SSL/TLS remaining length of data from the SSL/TLS segment to the HTTP2 buffer, and processing frame payload using the HTTP2 buffer.