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From: Stefano Brivio <sbrivio@redhat.com>
To: David Gibson <david@gibson.dropbear.id.au>
Cc: passt-dev@passt.top
Subject: Re: [PATCH 1/9] epoll: Generalize epoll_ref to cover things other than sockets
Date: Wed, 9 Aug 2023 21:59:10 +0200	[thread overview]
Message-ID: <20230809215743.22102e88@elisabeth> (raw)
In-Reply-To: <20230807134631.1400119-2-david@gibson.dropbear.id.au>

On Mon,  7 Aug 2023 23:46:23 +1000
David Gibson <david@gibson.dropbear.id.au> wrote:

> The epoll_ref type includes fields for the IP protocol of a socket, and the
> socket fd.  However, we already have a few things in the epoll which aren't
> protocol sockets, and we may have more in future.  Rename these fields to
> an abstract "fd type" and file descriptor for more generality.
> 
> Similarly, rather than using existing IP protocol numbers for the type,
> introduce our own number space.  For now these just correspond to the
> supported protocols, but we'll expand on that in future.
> 
> Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
> ---
>  icmp.c       |  6 +++---
>  passt.c      | 25 ++++++++++++-------------
>  passt.h      | 40 +++++++++++++++++++++++++++++-----------
>  tcp.c        | 22 +++++++++++-----------
>  tcp_conn.h   |  4 ++--
>  tcp_splice.c |  4 ++--
>  udp.c        | 14 +++++++-------
>  util.c       | 27 ++++++++++++++++++++-------
>  8 files changed, 86 insertions(+), 56 deletions(-)
> 
> diff --git a/icmp.c b/icmp.c
> index 676fa64..a4b6a47 100644
> --- a/icmp.c
> +++ b/icmp.c
> @@ -79,7 +79,7 @@ void icmp_sock_handler(const struct ctx *c, union epoll_ref ref,
>  	(void)events;
>  	(void)now;
>  
> -	n = recvfrom(ref.s, buf, sizeof(buf), 0, (struct sockaddr *)&sr, &sl);
> +	n = recvfrom(ref.fd, buf, sizeof(buf), 0, (struct sockaddr *)&sr, &sl);
>  	if (n < 0)
>  		return;
>  
> @@ -182,7 +182,7 @@ int icmp_tap_handler(const struct ctx *c, int af, const void *addr,
>  				    bind_if, id, iref.u32);
>  			if (s < 0)
>  				goto fail_sock;
> -			if (s > SOCKET_MAX) {
> +			if (s > FD_REF_MAX) {
>  				close(s);
>  				return 1;
>  			}
> @@ -236,7 +236,7 @@ int icmp_tap_handler(const struct ctx *c, int af, const void *addr,
>  				    bind_if, id, iref.u32);
>  			if (s < 0)
>  				goto fail_sock;
> -			if (s > SOCKET_MAX) {
> +			if (s > FD_REF_MAX) {
>  				close(s);
>  				return 1;
>  			}
> diff --git a/passt.c b/passt.c
> index 9123868..b42f42d 100644
> --- a/passt.c
> +++ b/passt.c
> @@ -55,12 +55,11 @@
>  
>  char pkt_buf[PKT_BUF_BYTES]	__attribute__ ((aligned(PAGE_SIZE)));
>  
> -char *ip_proto_str[IPPROTO_SCTP + 1] = {
> -	[IPPROTO_ICMP]		= "ICMP",
> -	[IPPROTO_TCP]		= "TCP",
> -	[IPPROTO_UDP]		= "UDP",
> -	[IPPROTO_ICMPV6]	= "ICMPV6",
> -	[IPPROTO_SCTP]		= "SCTP",
> +char *epoll_type_str[EPOLL_TYPE_MAX+1] = {

For consistency, given you're respinning anyway: [EPOLL_TYPE_MAX + 1]

> +	[EPOLL_TYPE_TCP]	= "TCP socket",
> +	[EPOLL_TYPE_UDP]	= "UDP socket",
> +	[EPOLL_TYPE_ICMP]	= "ICMP socket",
> +	[EPOLL_TYPE_ICMPV6]	= "ICMPv6 socket",
>  };
>  
>  /**
> @@ -73,16 +72,16 @@ char *ip_proto_str[IPPROTO_SCTP + 1] = {
>  static void sock_handler(struct ctx *c, union epoll_ref ref,
>  			 uint32_t events, const struct timespec *now)
>  {
> -	trace("%s: %s packet from socket %i (events: 0x%08x)",
> +	trace("%s: packet from %s %i (events: 0x%08x)",
>  	      c->mode == MODE_PASST ? "passt" : "pasta",
> -	      IP_PROTO_STR(ref.proto), ref.s, events);
> +	      EPOLL_TYPE_STR(ref.type), ref.fd, events);
>  
> -	if (!c->no_tcp && ref.proto == IPPROTO_TCP)
> -		tcp_sock_handler( c, ref, events, now);
> -	else if (!c->no_udp && ref.proto == IPPROTO_UDP)
> -		udp_sock_handler( c, ref, events, now);
> +	if (!c->no_tcp && ref.type == EPOLL_TYPE_TCP)
> +		tcp_sock_handler(c, ref, events, now);
> +	else if (!c->no_udp && ref.type == EPOLL_TYPE_UDP)
> +		udp_sock_handler(c, ref, events, now);
>  	else if (!c->no_icmp &&
> -		 (ref.proto == IPPROTO_ICMP || ref.proto == IPPROTO_ICMPV6))
> +		 (ref.type == EPOLL_TYPE_ICMP || ref.type == EPOLL_TYPE_ICMPV6))
>  		icmp_sock_handler(c, ref, events, now);
>  }
>  
> diff --git a/passt.h b/passt.h
> index edc4841..2110781 100644
> --- a/passt.h
> +++ b/passt.h
> @@ -42,9 +42,27 @@ union epoll_ref;
>  #include "udp.h"
>  
>  /**
> - * union epoll_ref - Breakdown of reference for epoll socket bookkeeping
> - * @proto:	IP protocol number
> - * @s:		Socket number (implies 2^24-1 limit on number of descriptors)
> + * enum epoll_type - Different types of fds we poll over
> + */
> +enum epoll_type {
> +	/* Special value to indicate an invalid type */
> +	EPOLL_TYPE_NONE = 0,
> +	/* Sockets and timerfds for TCP handling */
> +	EPOLL_TYPE_TCP,
> +	/* UDP sockets */
> +	EPOLL_TYPE_UDP,
> +	/* IPv4 ICMP sockets */
> +	EPOLL_TYPE_ICMP,
> +	/* ICMPv6 sockets */
> +	EPOLL_TYPE_ICMPV6,
> +
> +	EPOLL_TYPE_MAX = EPOLL_TYPE_ICMPV6,
> +};
> +
> +/**
> + * union epoll_ref - Breakdown of reference for epoll fd bookkeeping
> + * @type:	Type of fd (tells us what to do with events)
> + * @fd:		File descriptor number (implies < 2^24 total descriptors)
>   * @tcp:	TCP-specific reference part
>   * @udp:	UDP-specific reference part
>   * @icmp:	ICMP-specific reference part
> @@ -53,10 +71,10 @@ union epoll_ref;
>   */
>  union epoll_ref {
>  	struct {
> -		int32_t		proto:8,
> -#define SOCKET_REF_BITS		24
> -#define SOCKET_MAX		MAX_FROM_BITS(SOCKET_REF_BITS)
> -				s:SOCKET_REF_BITS;
> +		enum epoll_type type:8;
> +#define FD_REF_BITS		24
> +#define FD_REF_MAX		MAX_FROM_BITS(FD_REF_BITS)
> +		int32_t		fd:FD_REF_BITS;
>  		union {
>  			union tcp_epoll_ref tcp;
>  			union udp_epoll_ref udp;
> @@ -78,10 +96,10 @@ static_assert(sizeof(union epoll_ref) <= sizeof(union epoll_data),
>  #define PKT_BUF_BYTES		MAX(TAP_BUF_BYTES, 0)
>  extern char pkt_buf		[PKT_BUF_BYTES];
>  
> -extern char *ip_proto_str[];
> -#define IP_PROTO_STR(n)							\
> -	(((uint8_t)(n) <= IPPROTO_SCTP && ip_proto_str[(n)]) ?		\
> -			  ip_proto_str[(n)] : "?")
> +extern char *epoll_type_str[];
> +#define EPOLL_TYPE_STR(n)						\
> +	(((uint8_t)(n) <= EPOLL_TYPE_MAX && epoll_type_str[(n)]) ?	\
> +	                                    epoll_type_str[(n)] : "?")
>  
>  #include <resolv.h>	/* For MAXNS below */
>  
> diff --git a/tcp.c b/tcp.c
> index d9ecee5..18b781a 100644
> --- a/tcp.c
> +++ b/tcp.c
> @@ -643,7 +643,7 @@ static void conn_flag_do(const struct ctx *c, struct tcp_tap_conn *conn,
>  static int tcp_epoll_ctl(const struct ctx *c, struct tcp_tap_conn *conn)
>  {
>  	int m = conn->c.in_epoll ? EPOLL_CTL_MOD : EPOLL_CTL_ADD;
> -	union epoll_ref ref = { .proto = IPPROTO_TCP, .s = conn->sock,
> +	union epoll_ref ref = { .type = EPOLL_TYPE_TCP, .fd = conn->sock,
>  				.tcp.index = CONN_IDX(conn) };
>  	struct epoll_event ev = { .data.u64 = ref.u64 };
>  
> @@ -663,8 +663,8 @@ static int tcp_epoll_ctl(const struct ctx *c, struct tcp_tap_conn *conn)
>  	conn->c.in_epoll = true;
>  
>  	if (conn->timer != -1) {
> -		union epoll_ref ref_t = { .proto = IPPROTO_TCP,
> -					  .s = conn->sock,
> +		union epoll_ref ref_t = { .type = EPOLL_TYPE_TCP,
> +					  .fd = conn->sock,
>  					  .tcp.timer = 1,
>  					  .tcp.index = CONN_IDX(conn) };
>  		struct epoll_event ev_t = { .data.u64 = ref_t.u64,
> @@ -692,8 +692,8 @@ static void tcp_timer_ctl(const struct ctx *c, struct tcp_tap_conn *conn)
>  		return;
>  
>  	if (conn->timer == -1) {
> -		union epoll_ref ref = { .proto = IPPROTO_TCP,
> -					.s = conn->sock,
> +		union epoll_ref ref = { .type = EPOLL_TYPE_TCP,
> +					.fd = conn->sock,
>  					.tcp.timer = 1,
>  					.tcp.index = CONN_IDX(conn) };
>  		struct epoll_event ev = { .data.u64 = ref.u64,
> @@ -701,7 +701,7 @@ static void tcp_timer_ctl(const struct ctx *c, struct tcp_tap_conn *conn)
>  		int fd;
>  
>  		fd = timerfd_create(CLOCK_MONOTONIC, 0);
> -		if (fd == -1 || fd > SOCKET_MAX) {
> +		if (fd == -1 || fd > FD_REF_MAX) {
>  			debug("TCP: failed to get timer: %s", strerror(errno));
>  			if (fd > -1)
>  				close(fd);
> @@ -1908,7 +1908,7 @@ int tcp_conn_new_sock(const struct ctx *c, sa_family_t af)
>  
>  	s = socket(af, SOCK_STREAM | SOCK_NONBLOCK, IPPROTO_TCP);
>  
> -	if (s > SOCKET_MAX) {
> +	if (s > FD_REF_MAX) {
>  		close(s);
>  		return -EIO;
>  	}
> @@ -2791,7 +2791,7 @@ static void tcp_conn_from_sock(struct ctx *c, union epoll_ref ref,
>  	 * https://github.com/llvm/llvm-project/issues/58992
>  	 */
>  	memset(&sa, 0, sizeof(struct sockaddr_in6));
> -	s = accept4(ref.s, (struct sockaddr *)&sa, &sl, SOCK_NONBLOCK);
> +	s = accept4(ref.fd, (struct sockaddr *)&sa, &sl, SOCK_NONBLOCK);
>  	if (s < 0)
>  		return;
>  
> @@ -2948,7 +2948,7 @@ void tcp_sock_handler(struct ctx *c, union epoll_ref ref, uint32_t events,
>  	conn = tc + ref.tcp.index;
>  
>  	if (conn->c.spliced)
> -		tcp_splice_sock_handler(c, &conn->splice, ref.s, events);
> +		tcp_splice_sock_handler(c, &conn->splice, ref.fd, events);
>  	else
>  		tcp_tap_sock_handler(c, &conn->tap, events);
>  }
> @@ -2999,7 +2999,7 @@ static int tcp_sock_init_af(const struct ctx *c, int af, in_port_t port,
>  int tcp_sock_init(const struct ctx *c, sa_family_t af, const void *addr,
>  		  const char *ifname, in_port_t port)
>  {
> -	int r4 = SOCKET_MAX + 1, r6 = SOCKET_MAX + 1;
> +	int r4 = FD_REF_MAX + 1, r6 = FD_REF_MAX + 1;
>  
>  	if (af == AF_UNSPEC && c->ifi4 && c->ifi6)
>  		/* Attempt to get a dual stack socket */
> @@ -3013,7 +3013,7 @@ int tcp_sock_init(const struct ctx *c, sa_family_t af, const void *addr,
>  	if ((af == AF_INET6 || af == AF_UNSPEC) && c->ifi6)
>  		r6 = tcp_sock_init_af(c, AF_INET6, port, addr, ifname);
>  
> -	if (IN_INTERVAL(0, SOCKET_MAX, r4) || IN_INTERVAL(0, SOCKET_MAX, r6))
> +	if (IN_INTERVAL(0, FD_REF_MAX, r4) || IN_INTERVAL(0, FD_REF_MAX, r6))
>  		return 0;
>  
>  	return r4 < 0 ? r4 : r6;
> diff --git a/tcp_conn.h b/tcp_conn.h
> index 9e2b1bf..0b36940 100644
> --- a/tcp_conn.h
> +++ b/tcp_conn.h
> @@ -62,7 +62,7 @@ struct tcp_tap_conn {
>  	unsigned int	ws_to_tap	:TCP_WS_BITS;
>  
>  
> -	int		sock		:SOCKET_REF_BITS;
> +	int		sock		:FD_REF_BITS;
>  
>  	uint8_t		events;
>  #define CLOSED			0
> @@ -80,7 +80,7 @@ struct tcp_tap_conn {
>  	(SOCK_ACCEPTED | TAP_SYN_RCVD | ESTABLISHED)
>  
>  
> -	int		timer		:SOCKET_REF_BITS;
> +	int		timer		:FD_REF_BITS;
>  
>  	uint8_t		flags;
>  #define STALLED			BIT(0)
> diff --git a/tcp_splice.c b/tcp_splice.c
> index 03e14c1..24995e2 100644
> --- a/tcp_splice.c
> +++ b/tcp_splice.c
> @@ -173,9 +173,9 @@ static int tcp_splice_epoll_ctl(const struct ctx *c,
>  				struct tcp_splice_conn *conn)
>  {
>  	int m = conn->c.in_epoll ? EPOLL_CTL_MOD : EPOLL_CTL_ADD;
> -	union epoll_ref ref_a = { .proto = IPPROTO_TCP, .s = conn->a,
> +	union epoll_ref ref_a = { .type = EPOLL_TYPE_TCP, .fd = conn->a,
>  				  .tcp.index = CONN_IDX(conn) };
> -	union epoll_ref ref_b = { .proto = IPPROTO_TCP, .s = conn->b,
> +	union epoll_ref ref_b = { .type = EPOLL_TYPE_TCP, .fd = conn->b,
>  				  .tcp.index = CONN_IDX(conn) };
>  	struct epoll_event ev_a = { .data.u64 = ref_a.u64 };
>  	struct epoll_event ev_b = { .data.u64 = ref_b.u64 };
> diff --git a/udp.c b/udp.c
> index 5a852fb..62f8360 100644
> --- a/udp.c
> +++ b/udp.c
> @@ -388,9 +388,9 @@ static void udp_sock6_iov_init(const struct ctx *c)
>  int udp_splice_new(const struct ctx *c, int v6, in_port_t src, bool ns)
>  {
>  	struct epoll_event ev = { .events = EPOLLIN | EPOLLRDHUP | EPOLLHUP };
> -	union epoll_ref ref = { .proto = IPPROTO_UDP,
> +	union epoll_ref ref = { .type = EPOLL_TYPE_UDP,
>  				.udp = { .splice = true, .ns = ns,
> -					     .v6 = v6, .port = src }
> +					 .v6 = v6, .port = src }
>  			      };
>  	struct udp_splice_port *sp;
>  	int act, s;
> @@ -406,7 +406,7 @@ int udp_splice_new(const struct ctx *c, int v6, in_port_t src, bool ns)
>  	s = socket(v6 ? AF_INET6 : AF_INET, SOCK_DGRAM | SOCK_NONBLOCK,
>  		   IPPROTO_UDP);
>  
> -	if (s > SOCKET_MAX) {
> +	if (s > FD_REF_MAX) {
>  		close(s);
>  		return -EIO;
>  	}
> @@ -414,7 +414,7 @@ int udp_splice_new(const struct ctx *c, int v6, in_port_t src, bool ns)
>  	if (s < 0)
>  		return s;
>  
> -	ref.s = s;
> +	ref.fd = s;
>  
>  	if (v6) {
>  		struct sockaddr_in6 addr6 = {
> @@ -767,7 +767,7 @@ void udp_sock_handler(struct ctx *c, union epoll_ref ref, uint32_t events,
>  		udp4_localname.sin_port = htons(dstport);
>  	}
>  
> -	n = recvmmsg(ref.s, mmh_recv, n, 0, NULL);
> +	n = recvmmsg(ref.fd, mmh_recv, n, 0, NULL);
>  	if (n <= 0)
>  		return;
>  
> @@ -980,7 +980,7 @@ int udp_sock_init(const struct ctx *c, int ns, sa_family_t af,
>  		  const void *addr, const char *ifname, in_port_t port)
>  {
>  	union udp_epoll_ref uref = { .u32 = 0 };
> -	int s, r4 = SOCKET_MAX + 1, r6 = SOCKET_MAX + 1;
> +	int s, r4 = FD_REF_MAX + 1, r6 = FD_REF_MAX + 1;
>  
>  	if (ns) {
>  		uref.port = (in_port_t)(port + c->udp.fwd_out.f.delta[port]);
> @@ -1030,7 +1030,7 @@ int udp_sock_init(const struct ctx *c, int ns, sa_family_t af,
>  		}
>  	}
>  
> -	if (IN_INTERVAL(0, SOCKET_MAX, r4) || IN_INTERVAL(0, SOCKET_MAX, r6))
> +	if (IN_INTERVAL(0, FD_REF_MAX, r4) || IN_INTERVAL(0, FD_REF_MAX, r6))
>  		return 0;
>  
>  	return r4 < 0 ? r4 : r6;
> diff --git a/util.c b/util.c
> index 019c56c..2cac7ba 100644
> --- a/util.c
> +++ b/util.c
> @@ -102,7 +102,7 @@ int sock_l4(const struct ctx *c, int af, uint8_t proto,
>  	    const void *bind_addr, const char *ifname, uint16_t port,
>  	    uint32_t data)
>  {
> -	union epoll_ref ref = { .proto = proto, .data = data };
> +	union epoll_ref ref = { .data = data };
>  	struct sockaddr_in addr4 = {
>  		.sin_family = AF_INET,
>  		.sin_port = htons(port),
> @@ -118,9 +118,22 @@ int sock_l4(const struct ctx *c, int af, uint8_t proto,
>  	int fd, sl, y = 1, ret;
>  	struct epoll_event ev;
>  
> -	if (proto != IPPROTO_TCP && proto != IPPROTO_UDP &&
> -	    proto != IPPROTO_ICMP && proto != IPPROTO_ICMPV6)
> +	switch (proto) {
> +	case IPPROTO_TCP:
> +		ref.type = EPOLL_TYPE_TCP;
> +		break;
> +	case IPPROTO_UDP:
> +		ref.type = EPOLL_TYPE_UDP;
> +		break;
> +	case IPPROTO_ICMP:
> +		ref.type = EPOLL_TYPE_ICMP;
> +		break;
> +	case IPPROTO_ICMPV6:
> +		ref.type = EPOLL_TYPE_ICMPV6;
> +		break;
> +	default:
>  		return -EPFNOSUPPORT;	/* Not implemented. */
> +	}
>  
>  	if (af == AF_UNSPEC) {
>  		if (!DUAL_STACK_SOCKETS || bind_addr)
> @@ -140,12 +153,12 @@ int sock_l4(const struct ctx *c, int af, uint8_t proto,
>  		return ret;
>  	}
>  
> -	if (fd > SOCKET_MAX) {
> +	if (fd > FD_REF_MAX) {
>  		close(fd);
>  		return -EBADF;
>  	}
>  
> -	ref.s = fd;
> +	ref.fd = fd;
>  
>  	if (af == AF_INET) {
>  		if (bind_addr)
> @@ -188,8 +201,8 @@ int sock_l4(const struct ctx *c, int af, uint8_t proto,
>  		if (setsockopt(fd, SOL_SOCKET, SO_BINDTODEVICE,
>  			       ifname, strlen(ifname))) {
>  			ret = -errno;
> -			warn("Can't bind socket for %s port %u to %s, closing",
> -			     ip_proto_str[proto], port, ifname);
> +			warn("Can't bind %s socket for port %u to %s, closing",
> +			     EPOLL_TYPE_STR(proto), port, ifname);
>  			close(fd);
>  			return ret;
>  		}


  reply	other threads:[~2023-08-09 19:59 UTC|newest]

Thread overview: 17+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-08-07 13:46 [PATCH 0/9] Clean up to epoll dispatch David Gibson
2023-08-07 13:46 ` [PATCH 1/9] epoll: Generalize epoll_ref to cover things other than sockets David Gibson
2023-08-09 19:59   ` Stefano Brivio [this message]
2023-08-10  0:23     ` David Gibson
2023-08-07 13:46 ` [PATCH 2/9] epoll: Always use epoll_ref for the epoll data variable David Gibson
2023-08-07 13:46 ` [PATCH 3/9] epoll: Fold sock_handler into general switch on epoll event fd David Gibson
2023-08-07 13:46 ` [PATCH 4/9] epoll: Split handling of ICMP and ICMPv6 sockets David Gibson
2023-08-07 13:46 ` [PATCH 5/9] epoll: Tiny cleanup to udp_sock_handler() David Gibson
2023-08-07 13:46 ` [PATCH 6/9] epoll: Split handling of TCP timerfds into its own handler function David Gibson
2023-08-07 13:46 ` [PATCH 7/9] epoll: Split handling of listening TCP sockets into their own handler David Gibson
2023-08-09  6:29   ` David Gibson
2023-08-07 13:46 ` [PATCH 8/9] epoll: Split listening Unix domain socket into its own type David Gibson
2023-08-09 19:59   ` Stefano Brivio
2023-08-10  1:08     ` David Gibson
2023-08-10  7:50       ` Stefano Brivio
2023-08-11  3:17         ` David Gibson
2023-08-07 13:46 ` [PATCH 9/9] epoll: Use different epoll types for passt and pasta tap fds David Gibson

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