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epoll: Use different epoll types for passt and pasta tap fds

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Currently we have a single epoll event type for the "tap" fd, which could
be either a handle on a /dev/net/tun device (pasta) or a connected Unix
socket (passt).  However for the two modes we call different handler
functions.  Simplify this a little by using different epoll types and
dispatching directly to the correct handler function.

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 15:12:29 +10:00 committed by Stefano Brivio
parent eda4f1997e
commit ae5f6c8e1b
4 changed files with 30 additions and 30 deletions
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10
passt.c
View file

@ -63,7 +63,8 @@ char *epoll_type_str[EPOLL_TYPE_MAX + 1] = {
[EPOLL_TYPE_ICMP] = "ICMP socket", [EPOLL_TYPE_ICMP] = "ICMP socket",
[EPOLL_TYPE_ICMPV6] = "ICMPv6 socket", [EPOLL_TYPE_ICMPV6] = "ICMPv6 socket",
[EPOLL_TYPE_NSQUIT] = "namespace inotify", [EPOLL_TYPE_NSQUIT] = "namespace inotify",
[EPOLL_TYPE_TAP] = "tap device", [EPOLL_TYPE_TAP_PASTA] = "/dev/net/tun device",
[EPOLL_TYPE_TAP_PASST] = "connected qemu socket",
[EPOLL_TYPE_TAP_LISTEN] = "listening qemu socket", [EPOLL_TYPE_TAP_LISTEN] = "listening qemu socket",
}; };
@ -317,8 +318,11 @@ loop:
EPOLL_TYPE_STR(ref.type), ref.fd, eventmask); EPOLL_TYPE_STR(ref.type), ref.fd, eventmask);
switch (ref.type) { switch (ref.type) {
case EPOLL_TYPE_TAP: case EPOLL_TYPE_TAP_PASTA:
tap_handler(&c, events[i].events, &now); tap_handler_pasta(&c, eventmask, &now);
break;
case EPOLL_TYPE_TAP_PASST:
tap_handler_passt(&c, eventmask, &now);
break; break;
case EPOLL_TYPE_TAP_LISTEN: case EPOLL_TYPE_TAP_LISTEN:
tap_listen_handler(&c, eventmask); tap_listen_handler(&c, eventmask);

6
passt.h
View file

@ -61,8 +61,10 @@ enum epoll_type {
EPOLL_TYPE_ICMPV6, EPOLL_TYPE_ICMPV6,
/* inotify fd watching for end of netns (pasta) */ /* inotify fd watching for end of netns (pasta) */
EPOLL_TYPE_NSQUIT, EPOLL_TYPE_NSQUIT,
/* tap char device, or connected qemu socket fd */ /* tuntap character device */
EPOLL_TYPE_TAP, EPOLL_TYPE_TAP_PASTA,
/* socket connected to qemu */
EPOLL_TYPE_TAP_PASST,
/* socket listening for qemu socket connections */ /* socket listening for qemu socket connections */
EPOLL_TYPE_TAP_LISTEN, EPOLL_TYPE_TAP_LISTEN,

35
tap.c
View file

@ -914,7 +914,7 @@ static void tap_sock_reset(struct ctx *c)
* @events: epoll events * @events: epoll events
* @now: Current timestamp * @now: Current timestamp
*/ */
static void tap_handler_passt(struct ctx *c, uint32_t events, void tap_handler_passt(struct ctx *c, uint32_t events,
const struct timespec *now) const struct timespec *now)
{ {
struct ethhdr *eh; struct ethhdr *eh;
@ -996,12 +996,12 @@ next:
} }
/** /**
* tap_handler_pasta() - Packet handler for tuntap file descriptor * tap_handler_pasta() - Packet handler for /dev/net/tun file descriptor
* @c: Execution context * @c: Execution context
* @events: epoll events * @events: epoll events
* @now: Current timestamp * @now: Current timestamp
*/ */
static void tap_handler_pasta(struct ctx *c, uint32_t events, void tap_handler_pasta(struct ctx *c, uint32_t events,
const struct timespec *now) const struct timespec *now)
{ {
ssize_t n, len; ssize_t n, len;
@ -1143,7 +1143,7 @@ static void tap_sock_unix_init(struct ctx *c)
*/ */
void tap_listen_handler(struct ctx *c, uint32_t events) void tap_listen_handler(struct ctx *c, uint32_t events)
{ {
union epoll_ref ref = { .type = EPOLL_TYPE_TAP }; union epoll_ref ref = { .type = EPOLL_TYPE_TAP_PASST };
struct epoll_event ev = { 0 }; struct epoll_event ev = { 0 };
int v = INT_MAX / 2; int v = INT_MAX / 2;
struct ucred ucred; struct ucred ucred;
@ -1225,12 +1225,12 @@ static int tap_ns_tun(void *arg)
} }
/** /**
* tap_sock_init_tun() - Set up tuntap file descriptor * tap_sock_tun_init() - Set up /dev/net/tun file descriptor
* @c: Execution context * @c: Execution context
*/ */
static void tap_sock_tun_init(struct ctx *c) static void tap_sock_tun_init(struct ctx *c)
{ {
union epoll_ref ref = { .type = EPOLL_TYPE_TAP }; union epoll_ref ref = { .type = EPOLL_TYPE_TAP_PASTA };
struct epoll_event ev = { 0 }; struct epoll_event ev = { 0 };
NS_CALL(tap_ns_tun, c); NS_CALL(tap_ns_tun, c);
@ -1263,11 +1263,16 @@ void tap_sock_init(struct ctx *c)
} }
if (c->fd_tap != -1) { /* Passed as --fd */ if (c->fd_tap != -1) { /* Passed as --fd */
union epoll_ref ref = { .type = EPOLL_TYPE_TAP };
struct epoll_event ev = { 0 }; struct epoll_event ev = { 0 };
ASSERT(c->one_off); union epoll_ref ref;
ASSERT(c->one_off);
ref.fd = c->fd_tap; ref.fd = c->fd_tap;
if (c->mode == MODE_PASST)
ref.type = EPOLL_TYPE_TAP_PASST;
else
ref.type = EPOLL_TYPE_TAP_PASTA;
ev.events = EPOLLIN | EPOLLET | EPOLLRDHUP; ev.events = EPOLLIN | EPOLLET | EPOLLRDHUP;
ev.data.u64 = ref.u64; ev.data.u64 = ref.u64;
epoll_ctl(c->epollfd, EPOLL_CTL_ADD, c->fd_tap, &ev); epoll_ctl(c->epollfd, EPOLL_CTL_ADD, c->fd_tap, &ev);
@ -1281,17 +1286,3 @@ void tap_sock_init(struct ctx *c)
tap_sock_tun_init(c); tap_sock_tun_init(c);
} }
} }
/**
* tap_handler() - Packet handler for AF_UNIX or tuntap file descriptor
* @c: Execution context
* @events: epoll events
* @now: Current timestamp, can be NULL on EPOLLERR
*/
void tap_handler(struct ctx *c, uint32_t events, const struct timespec *now)
{
if (c->mode == MODE_PASST)
tap_handler_passt(c, events, now);
else if (c->mode == MODE_PASTA)
tap_handler_pasta(c, events, now);
}

5
tap.h
View file

@ -77,7 +77,10 @@ void tap_send_frames(struct ctx *c, const struct iovec *iov, size_t n);
void tap_update_mac(struct tap_hdr *taph, void tap_update_mac(struct tap_hdr *taph,
const unsigned char *eth_d, const unsigned char *eth_s); const unsigned char *eth_d, const unsigned char *eth_s);
void tap_listen_handler(struct ctx *c, uint32_t events); void tap_listen_handler(struct ctx *c, uint32_t events);
void tap_handler(struct ctx *c, uint32_t events, const struct timespec *now); void tap_handler_pasta(struct ctx *c, uint32_t events,
const struct timespec *now);
void tap_handler_passt(struct ctx *c, uint32_t events,
const struct timespec *now);
void tap_sock_init(struct ctx *c); void tap_sock_init(struct ctx *c);
#endif /* TAP_H */ #endif /* TAP_H */