A Sept 2021 MESA research report analyzes a Chinese patent (application 200710130726.7) for out-of-path UDP session blocking via forged ICMP destination/port-unreachable packets injected by raw socket, verifies the exact Linux 3.10.0 kernel code path that propagates the resulting ECONNREFUSED to the application layer, and empirically demonstrates it fully blocks Chrome's QUIC connections to Google (effective for all 16 ICMP unreachable subcodes, and through NAT), with Chrome falling back to HTTP/2 within seconds; combining it with TCP RST additionally blocks the HTTP/2 fallback.

sapp's plugin API exposes explicit enforcement primitives -- MESA_kill_tcp()/MESA_rst_tcp() to inject a single RST, and MESA_set_stream_opt() with MSO_TCP_RST_REMEDY/MSO_DROP_STREAM to make RST-injection or packet-dropping persist for the remaining lifetime of a flow -- with a global sapp.toml auto_remedy toggle and a per-stream option controlling whether a lone RST is reinforced repeatedly for as long as the flow keeps sending data.

sapp's internal architecture guide documents three deployment topologies (mirror/passive-tap, inline, dual-arm transparent) and four distinct methods for injecting blocking packets back onto the wire, including a MAC-in-MAC scheme that extracts device/link IDs from mirrored traffic's source MAC field to route an injected packet to the correct physically separate inline device over VXLAN when multiple injection points exist.

A production feature spec ("加密协议JG") requires detection-and-control capability for QUIC, ESNI, and ECH, with a per-connection log field c_encrypt_type explicitly distinguishing ClientHello encryption (0=unencrypted, 1=ESNI, 2=ECH) and a DF_QUIC_REGION rule table matching QUIC by SNI. The system computes a per-rule "CT" (穿透/penetration) rate from paired mirror-vs-functional RST-packet logs (TF-RST-LOG / TF-MIRROR-RST-LOG) to grade each block rule's effectiveness, and runs continuous active-verification probes against its own rules, deliberately varying the probe 4-tuple each run "to ensure it doesn't hit the blacklist" so the verification traffic itself reaches the target.

An official "Geedge Networks Confidential And Proprietary" sapp/mrzcpd operations manual documents the packet-injection API (MESA_kill_tcp / MESA_inject_pkt) used for both out-of-band mirror-tap RST injection (relies on the local box's own IP routing table to send) and inline in-path injection (requires mrtunnat.conf tunnel-tracking state -- use_recent_tunnel, use_link_info_table -- keyed on outer/inner MAC and link_id/link_dir), plus the Marsio DPDK-based driver's I/O sub-modes (marsio4, marsio_vxlan, pag_marsio, agent_smith) and its role extracting VXLAN/GTP encapsulation metadata and stamping link/circuit identifiers into mirrored packets' MAC field for session-log correlation.

Commit history in the core sapp DPI engine repo (MESA_Platform/sapp) shows its RST-style blocking/injection path is internally called "欺骗包" (literally "deceptive/spoofed packet") injection, implemented via a sapp_inject_ctrl_pkt function that sends forged control packets to all devices opened through the marsio packet-I/O layer; ticket TSG-20317 documents active, ongoing optimization of "inject packet duplicate traffic detection" performance in this code path as of 2024.

"stellar" (git.mesalab.cn / geedgenetworks.com) is a C++ core DPI packet-processing engine with protocol decoders (HTTP, FTP, mail, QUIC, RTP, SIP, DTLS, SSL, DNS, SOCKS, stratum) and a dedicated packet-injection module (src/stellar/inject.cpp) with an extensive TCP-RST-injection test suite covering injection timed after SYN, SYN-ACK, first C2S payload, and sub-ACK. It integrates the MAAT rule engine (security_enforcer.cpp / scanner_maat.c, "Security enforcer maat plugin table"), the Marsio packet-I/O framework (marsio_io.cpp), and glimpse_detector as an integrated decoder plugin ("integration glimpse_detector", "rename to lpi plugin").