# HG changeset patch # User maxime <mu...@live.be> # Date 1715859913 -7200 # Thu May 16 13:45:13 2024 +0200 # Node ID 71a8642308e94bf1005a8f4927506c142742260b # Parent 74012b4ab947ce4b3e42cb75a7239f0447aacffc Mail: added MPTCP support.
Multipath TCP (MPTCP), standardized in RFC8684 [1], is a TCP extension that enables a TCP connection to use different paths. Multipath TCP has been used for several use cases. On smartphones, MPTCP enables seamless handovers between cellular and Wi-Fi networks while preserving established connections. This use-case is what pushed Apple to use MPTCP since 2013 in multiple applications [2]. On dual-stack hosts, Multipath TCP enables the TCP connection to automatically use the best performing path, either IPv4 or IPv6. If one path fails, MPTCP automatically uses the other path. To benefit from MPTCP, both the client and the server have to support it. Multipath TCP is a backward-compatible TCP extension that is enabled by default on recent Linux distributions (Debian, Ubuntu, Redhat, ...). Multipath TCP is included in the Linux kernel since version 5.6 [3]. To use it on Linux, an application must explicitly enable it when creating the socket. No need to change anything else in the application. Even if MPTCP is supported by different OS, only Linux supports the `IPPROTO_MPTCP` protocol, which is why this feature is currently limited to Linux only. This patch adds a new parameter 'mptcp' to the 'listen' directive in the Mail module. Link: https://www.rfc-editor.org/rfc/rfc8684.html [1] Link: https://www.tessares.net/apples-mptcp-story-so-far/ [2] Link: https://www.mptcp.dev [3] diff --git a/src/mail/ngx_mail.c b/src/mail/ngx_mail.c --- a/src/mail/ngx_mail.c +++ b/src/mail/ngx_mail.c @@ -332,6 +332,7 @@ ngx_mail_optimize_servers(ngx_conf_t *cf ls->log.data = &ls->addr_text; ls->log.handler = ngx_accept_log_error; + ls->protocol = addr[i].opt.protocol; ls->backlog = addr[i].opt.backlog; ls->rcvbuf = addr[i].opt.rcvbuf; ls->sndbuf = addr[i].opt.sndbuf; diff --git a/src/mail/ngx_mail.h b/src/mail/ngx_mail.h --- a/src/mail/ngx_mail.h +++ b/src/mail/ngx_mail.h @@ -47,6 +47,7 @@ typedef struct { int tcp_keepintvl; int tcp_keepcnt; #endif + int protocol; int backlog; int rcvbuf; int sndbuf; diff --git a/src/mail/ngx_mail_core_module.c b/src/mail/ngx_mail_core_module.c --- a/src/mail/ngx_mail_core_module.c +++ b/src/mail/ngx_mail_core_module.c @@ -10,6 +10,10 @@ #include <ngx_event.h> #include <ngx_mail.h> +#ifndef IPPROTO_MPTCP +#define IPPROTO_MPTCP 262 +#endif + static void *ngx_mail_core_create_main_conf(ngx_conf_t *cf); static void *ngx_mail_core_create_srv_conf(ngx_conf_t *cf); @@ -477,6 +481,12 @@ ngx_mail_core_listen(ngx_conf_t *cf, ngx #endif } + if (ngx_strcmp(value[i].data, "mptcp") == 0) { + ls->protocol = IPPROTO_MPTCP; + continue; + } + + if (ngx_strncmp(value[i].data, "so_keepalive=", 13) == 0) { if (ngx_strcmp(&value[i].data[13], "on") == 0) { -- nginx-devel mailing list nginx-devel@freenginx.org https://freenginx.org/mailman/listinfo/nginx-devel
