diff options
Diffstat (limited to 'src/proto_uxdg.c')
| -rw-r--r-- | src/proto_uxdg.c | 159 |
1 files changed, 159 insertions, 0 deletions
diff --git a/src/proto_uxdg.c b/src/proto_uxdg.c new file mode 100644 index 0000000..43cbe5a --- /dev/null +++ b/src/proto_uxdg.c @@ -0,0 +1,159 @@ +/* + * DGRAM protocol layer on top of AF_UNIX + * + * Copyright 2020 HAProxy Technologies, Emeric Brun <ebrun@haproxy.com> + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; either version + * 2 of the License, or (at your option) any later version. + * + */ + +#include <ctype.h> +#include <errno.h> +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <time.h> + +#include <sys/param.h> +#include <sys/socket.h> +#include <sys/types.h> +#include <sys/un.h> + +#include <haproxy/fd.h> +#include <haproxy/listener.h> +#include <haproxy/log.h> +#include <haproxy/namespace.h> +#include <haproxy/protocol.h> +#include <haproxy/sock.h> +#include <haproxy/sock_unix.h> +#include <haproxy/tools.h> + +static int uxdg_bind_listener(struct listener *listener, char *errmsg, int errlen); +static void uxdg_enable_listener(struct listener *listener); +static void uxdg_disable_listener(struct listener *listener); +static int uxdg_suspend_receiver(struct receiver *rx); + +/* Note: must not be declared <const> as its list will be overwritten */ +struct protocol proto_uxdg = { + .name = "uxdg", + + /* connection layer */ + .xprt_type = PROTO_TYPE_DGRAM, + .listen = uxdg_bind_listener, + .enable = uxdg_enable_listener, + .disable = uxdg_disable_listener, + .add = default_add_listener, + .unbind = default_unbind_listener, + .suspend = default_suspend_listener, + .resume = default_resume_listener, + + /* binding layer */ + .rx_suspend = uxdg_suspend_receiver, + + /* address family */ + .fam = &proto_fam_unix, + + /* socket layer */ + .proto_type = PROTO_TYPE_DGRAM, + .sock_type = SOCK_DGRAM, + .sock_prot = 0, + .rx_enable = sock_enable, + .rx_disable = sock_disable, + .rx_unbind = sock_unbind, + .receivers = LIST_HEAD_INIT(proto_uxdg.receivers), + .nb_receivers = 0, +}; + +INITCALL1(STG_REGISTER, protocol_register, &proto_uxdg); + +/* This function tries to bind dgram unix socket listener. It may return a warning or + * an error message in <errmsg> if the message is at most <errlen> bytes long + * (including '\0'). Note that <errmsg> may be NULL if <errlen> is also zero. + * The return value is composed from ERR_ABORT, ERR_WARN, + * ERR_ALERT, ERR_RETRYABLE and ERR_FATAL. ERR_NONE indicates that everything + * was alright and that no message was returned. ERR_RETRYABLE means that an + * error occurred but that it may vanish after a retry (eg: port in use), and + * ERR_FATAL indicates a non-fixable error. ERR_WARN and ERR_ALERT do not alter + * the meaning of the error, but just indicate that a message is present which + * should be displayed with the respective level. Last, ERR_ABORT indicates + * that it's pointless to try to start other listeners. No error message is + * returned if errlen is NULL. + */ +int uxdg_bind_listener(struct listener *listener, char *errmsg, int errlen) +{ + int err = ERR_NONE; + char *msg = NULL; + + /* ensure we never return garbage */ + if (errlen) + *errmsg = 0; + + if (listener->state != LI_ASSIGNED) + return ERR_NONE; /* already bound */ + + if (!(listener->rx.flags & RX_F_BOUND)) { + msg = "receiving socket not bound"; + err |= ERR_FATAL | ERR_ALERT; + goto uxdg_return; + } + + listener_set_state(listener, LI_LISTEN); + + uxdg_return: + if (msg && errlen) { + char *path_str; + + path_str = sa2str((struct sockaddr_storage *)&listener->rx.addr, 0, 0); + snprintf(errmsg, errlen, "%s for [%s]", msg, ((path_str) ? path_str : "")); + ha_free(&path_str); + } + return err; +} + +/* Enable receipt of incoming connections for listener <l>. The receiver must + * still be valid. + */ +static void uxdg_enable_listener(struct listener *l) +{ + fd_want_recv_safe(l->rx.fd); +} + +/* Disable receipt of incoming connections for listener <l>. The receiver must + * still be valid. + */ +static void uxdg_disable_listener(struct listener *l) +{ + fd_stop_recv(l->rx.fd); +} + +/* Suspend a receiver. Returns < 0 in case of failure, 0 if the receiver + * was totally stopped, or > 0 if correctly suspended. For plain unix sockets + * we only disable the listener to prevent data from being handled but nothing + * more is done since currently it's the new process which handles the renaming. + * Abstract sockets are completely unbound and closed so there's no need to stop + * the poller. + */ +static int uxdg_suspend_receiver(struct receiver *rx) +{ + struct listener *l = LIST_ELEM(rx, struct listener *, rx); + + if (((struct sockaddr_un *)&rx->addr)->sun_path[0]) { + uxdg_disable_listener(l); + return 1; + } + + /* Listener's lock already held. Call lockless version of + * unbind_listener. */ + do_unbind_listener(l); + return 0; +} + +/* + * Local variables: + * c-indent-level: 8 + * c-basic-offset: 8 + * End: + */ |