epoll: Split handling of TCP timerfds into its own handler function

tcp_sock_handler() actually handles several different types of fd events.
This includes timerfds that aren't sockets at all.  The handling of these
has essentially nothing in common with the other cases.  So, give the
TCP timers there own epoll_type value and dispatch directly to their
handler.  This also means we can remove the timer field from tcp_epoll_ref,
the information it encoded is now implicit in the epoll_type value.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
This commit is contained in:
David Gibson 2023-08-11 15:12:26 +10:00 committed by Stefano Brivio
parent 8271a2ed57
commit e6f81e5578
4 changed files with 12 additions and 14 deletions

View file

@ -57,6 +57,7 @@ char pkt_buf[PKT_BUF_BYTES] __attribute__ ((aligned(PAGE_SIZE)));
char *epoll_type_str[EPOLL_TYPE_MAX + 1] = { char *epoll_type_str[EPOLL_TYPE_MAX + 1] = {
[EPOLL_TYPE_TCP] = "TCP socket", [EPOLL_TYPE_TCP] = "TCP socket",
[EPOLL_TYPE_TCP_TIMER] = "TCP timer",
[EPOLL_TYPE_UDP] = "UDP socket", [EPOLL_TYPE_UDP] = "UDP socket",
[EPOLL_TYPE_ICMP] = "ICMP socket", [EPOLL_TYPE_ICMP] = "ICMP socket",
[EPOLL_TYPE_ICMPV6] = "ICMPv6 socket", [EPOLL_TYPE_ICMPV6] = "ICMPv6 socket",
@ -324,6 +325,9 @@ loop:
if (!c.no_tcp) if (!c.no_tcp)
tcp_sock_handler(&c, ref, eventmask, &now); tcp_sock_handler(&c, ref, eventmask, &now);
break; break;
case EPOLL_TYPE_TCP_TIMER:
tcp_timer_handler(&c, ref);
break;
case EPOLL_TYPE_UDP: case EPOLL_TYPE_UDP:
udp_sock_handler(&c, ref, eventmask, &now); udp_sock_handler(&c, ref, eventmask, &now);
break; break;

View file

@ -47,8 +47,10 @@ union epoll_ref;
enum epoll_type { enum epoll_type {
/* Special value to indicate an invalid type */ /* Special value to indicate an invalid type */
EPOLL_TYPE_NONE = 0, EPOLL_TYPE_NONE = 0,
/* Sockets and timerfds for TCP handling */ /* TCP sockets */
EPOLL_TYPE_TCP, EPOLL_TYPE_TCP,
/* timerfds used for TCP timers */
EPOLL_TYPE_TCP_TIMER,
/* UDP sockets */ /* UDP sockets */
EPOLL_TYPE_UDP, EPOLL_TYPE_UDP,
/* IPv4 ICMP sockets */ /* IPv4 ICMP sockets */

15
tcp.c
View file

@ -663,9 +663,8 @@ static int tcp_epoll_ctl(const struct ctx *c, struct tcp_tap_conn *conn)
conn->c.in_epoll = true; conn->c.in_epoll = true;
if (conn->timer != -1) { if (conn->timer != -1) {
union epoll_ref ref_t = { .type = EPOLL_TYPE_TCP, union epoll_ref ref_t = { .type = EPOLL_TYPE_TCP_TIMER,
.fd = conn->sock, .fd = conn->sock,
.tcp.timer = 1,
.tcp.index = CONN_IDX(conn) }; .tcp.index = CONN_IDX(conn) };
struct epoll_event ev_t = { .data.u64 = ref_t.u64, struct epoll_event ev_t = { .data.u64 = ref_t.u64,
.events = EPOLLIN | EPOLLET }; .events = EPOLLIN | EPOLLET };
@ -692,9 +691,8 @@ static void tcp_timer_ctl(const struct ctx *c, struct tcp_tap_conn *conn)
return; return;
if (conn->timer == -1) { if (conn->timer == -1) {
union epoll_ref ref = { .type = EPOLL_TYPE_TCP, union epoll_ref ref = { .type = EPOLL_TYPE_TCP_TIMER,
.fd = conn->sock, .fd = conn->sock,
.tcp.timer = 1,
.tcp.index = CONN_IDX(conn) }; .tcp.index = CONN_IDX(conn) };
struct epoll_event ev = { .data.u64 = ref.u64, struct epoll_event ev = { .data.u64 = ref.u64,
.events = EPOLLIN | EPOLLET }; .events = EPOLLIN | EPOLLET };
@ -2813,12 +2811,12 @@ static void tcp_conn_from_sock(struct ctx *c, union epoll_ref ref,
* *
* #syscalls timerfd_gettime * #syscalls timerfd_gettime
*/ */
static void tcp_timer_handler(struct ctx *c, union epoll_ref ref) void tcp_timer_handler(struct ctx *c, union epoll_ref ref)
{ {
struct tcp_tap_conn *conn = conn_at_idx(ref.tcp.index); struct tcp_tap_conn *conn = conn_at_idx(ref.tcp.index);
struct itimerspec check_armed = { { 0 }, { 0 } }; struct itimerspec check_armed = { { 0 }, { 0 } };
if (!conn) if (c->no_tcp || !conn)
return; return;
/* We don't reset timers on ~ACK_FROM_TAP_DUE, ~ACK_TO_TAP_DUE. If the /* We don't reset timers on ~ACK_FROM_TAP_DUE, ~ACK_TO_TAP_DUE. If the
@ -2935,11 +2933,6 @@ void tcp_sock_handler(struct ctx *c, union epoll_ref ref, uint32_t events,
{ {
union tcp_conn *conn; union tcp_conn *conn;
if (ref.tcp.timer) {
tcp_timer_handler(c, ref);
return;
}
if (ref.tcp.listen) { if (ref.tcp.listen) {
tcp_conn_from_sock(c, ref, now); tcp_conn_from_sock(c, ref, now);
return; return;

3
tcp.h
View file

@ -13,6 +13,7 @@
struct ctx; struct ctx;
void tcp_timer_handler(struct ctx *c, union epoll_ref ref);
void tcp_sock_handler(struct ctx *c, union epoll_ref ref, uint32_t events, void tcp_sock_handler(struct ctx *c, union epoll_ref ref, uint32_t events,
const struct timespec *now); const struct timespec *now);
int tcp_tap_handler(struct ctx *c, int af, const void *addr, int tcp_tap_handler(struct ctx *c, int af, const void *addr,
@ -31,7 +32,6 @@ void tcp_update_l2_buf(const unsigned char *eth_d, const unsigned char *eth_s,
* union tcp_epoll_ref - epoll reference portion for TCP connections * union tcp_epoll_ref - epoll reference portion for TCP connections
* @listen: Set if this file descriptor is a listening socket * @listen: Set if this file descriptor is a listening socket
* @outbound: Listening socket maps to outbound, spliced connection * @outbound: Listening socket maps to outbound, spliced connection
* @timer: Reference is a timerfd descriptor for connection
* @index: Index of connection in table, or port for bound sockets * @index: Index of connection in table, or port for bound sockets
* @u32: Opaque u32 value of reference * @u32: Opaque u32 value of reference
*/ */
@ -39,7 +39,6 @@ union tcp_epoll_ref {
struct { struct {
uint32_t listen:1, uint32_t listen:1,
outbound:1, outbound:1,
timer:1,
index:20; index:20;
}; };
uint32_t u32; uint32_t u32;