mirrors/passt
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity Actions

icmp: Store ping socket information in flow table

Browse source 
Currently icmp_id_map[][] stores information about ping sockets in a
bespoke structure.  Move the same information into new types of flow
in the flow table.  To match that change, replace the existing ICMP
timer with a flow-based timer for expiring ping sockets.  This has the
advantage that we only need to scan the active flows, not all possible
ids.

We convert icmp_id_map[][] to point to the flow table entries, rather
than containing its own information.  We do still use that array for
locating the right ping flows, rather than using a "flow native" form
of lookup for the time being.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
[sbrivio: Update id_sock description in comment to icmp_ping_new()]
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
This commit is contained in:
David Gibson 2024-02-29 15:15:32 +11:00 committed by Stefano Brivio
parent 383a6f67e5
commit 3af5e9fdba
8 changed files with 117 additions and 89 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

6
Makefile
View file

@ -54,9 +54,9 @@ SRCS = $(PASST_SRCS) $(QRAP_SRCS)
MANPAGES = passt.1 pasta.1 qrap.1 MANPAGES = passt.1 pasta.1 qrap.1
PASST_HEADERS = arch.h arp.h checksum.h conf.h dhcp.h dhcpv6.h flow.h fwd.h \ PASST_HEADERS = arch.h arp.h checksum.h conf.h dhcp.h dhcpv6.h flow.h fwd.h \
flow_table.h icmp.h inany.h iov.h ip.h isolation.h lineread.h log.h \ flow_table.h icmp.h icmp_flow.h inany.h iov.h ip.h isolation.h \
ndp.h netlink.h packet.h passt.h pasta.h pcap.h pif.h siphash.h tap.h \ lineread.h log.h ndp.h netlink.h packet.h passt.h pasta.h pcap.h pif.h \
tcp.h tcp_conn.h tcp_splice.h udp.h util.h siphash.h tap.h tcp.h tcp_conn.h tcp_splice.h udp.h util.h
HEADERS = $(PASST_HEADERS) seccomp.h HEADERS = $(PASST_HEADERS) seccomp.h
C := \#include <linux/tcp.h>\nstruct tcp_info x = { .tcpi_snd_wnd = 0 }; C := \#include <linux/tcp.h>\nstruct tcp_info x = { .tcpi_snd_wnd = 0 };

9
flow.c
View file

@ -22,6 +22,8 @@ const char *flow_type_str[] = {
[FLOW_TYPE_NONE] = "<none>", [FLOW_TYPE_NONE] = "<none>",
[FLOW_TCP] = "TCP connection", [FLOW_TCP] = "TCP connection",
[FLOW_TCP_SPLICE] = "TCP connection (spliced)", [FLOW_TCP_SPLICE] = "TCP connection (spliced)",
[FLOW_PING4] = "ICMP ping sequence",
[FLOW_PING6] = "ICMPv6 ping sequence",
}; };
static_assert(ARRAY_SIZE(flow_type_str) == FLOW_NUM_TYPES, static_assert(ARRAY_SIZE(flow_type_str) == FLOW_NUM_TYPES,
"flow_type_str[] doesn't match enum flow_type"); "flow_type_str[] doesn't match enum flow_type");
@ -29,6 +31,8 @@ static_assert(ARRAY_SIZE(flow_type_str) == FLOW_NUM_TYPES,
const uint8_t flow_proto[] = { const uint8_t flow_proto[] = {
[FLOW_TCP] = IPPROTO_TCP, [FLOW_TCP] = IPPROTO_TCP,
[FLOW_TCP_SPLICE] = IPPROTO_TCP, [FLOW_TCP_SPLICE] = IPPROTO_TCP,
[FLOW_PING4] = IPPROTO_ICMP,
[FLOW_PING6] = IPPROTO_ICMPV6,
}; };
static_assert(ARRAY_SIZE(flow_proto) == FLOW_NUM_TYPES, static_assert(ARRAY_SIZE(flow_proto) == FLOW_NUM_TYPES,
"flow_proto[] doesn't match enum flow_type"); "flow_proto[] doesn't match enum flow_type");
@ -295,6 +299,11 @@ void flow_defer_handler(const struct ctx *c, const struct timespec *now)
if (!closed && timer) if (!closed && timer)
tcp_splice_timer(c, flow); tcp_splice_timer(c, flow);
break; break;
case FLOW_PING4:
case FLOW_PING6:
if (timer)
closed = icmp_ping_timer(c, flow, now);
break;
default: default:
/* Assume other flow types don't need any handling */ /* Assume other flow types don't need any handling */
; ;

4
flow.h
View file

@ -19,6 +19,10 @@ enum flow_type {
FLOW_TCP, FLOW_TCP,
/* A TCP connection between a host socket and ns socket */ /* A TCP connection between a host socket and ns socket */
FLOW_TCP_SPLICE, FLOW_TCP_SPLICE,
/* ICMP echo requests from guest to host and matching replies back */
FLOW_PING4,
/* ICMPv6 echo requests from guest to host and matching replies back */
FLOW_PING6,
FLOW_NUM_TYPES, FLOW_NUM_TYPES,
}; };

2
flow_table.h
View file

@ -8,6 +8,7 @@
#define FLOW_TABLE_H #define FLOW_TABLE_H
#include "tcp_conn.h" #include "tcp_conn.h"
#include "icmp_flow.h"
/** /**
* struct flow_free_cluster - Information about a cluster of free entries * struct flow_free_cluster - Information about a cluster of free entries
@ -33,6 +34,7 @@ union flow {
struct flow_free_cluster free; struct flow_free_cluster free;
struct tcp_tap_conn tcp; struct tcp_tap_conn tcp;
struct tcp_splice_conn tcp_splice; struct tcp_splice_conn tcp_splice;
struct icmp_ping_flow ping;
}; };
/* Global Flow Table */ /* Global Flow Table */

141
icmp.c
View file

@ -40,24 +40,17 @@
#include "siphash.h" #include "siphash.h"
#include "inany.h" #include "inany.h"
#include "icmp.h" #include "icmp.h"
#include "flow_table.h"
#define ICMP_ECHO_TIMEOUT 60 /* s, timeout for ICMP socket activity */ #define ICMP_ECHO_TIMEOUT 60 /* s, timeout for ICMP socket activity */
#define ICMP_NUM_IDS (1U << 16) #define ICMP_NUM_IDS (1U << 16)
/** /* Sides of a flow as we use them for ping streams */
* struct icmp_id_sock - Tracking information for single ICMP echo identifier #define SOCKSIDE 0
* @sock: Bound socket for identifier #define TAPSIDE 1
* @seq: Last sequence number sent to tap, host order, -1: not sent yet
* @ts: Last associated activity from tap, seconds
*/
struct icmp_id_sock {
int sock;
int seq;
time_t ts;
};
/* Indexed by ICMP echo identifier */ /* Indexed by ICMP echo identifier */
static struct icmp_id_sock icmp_id_map[IP_VERSIONS][ICMP_NUM_IDS]; static struct icmp_ping_flow *icmp_id_map[IP_VERSIONS][ICMP_NUM_IDS];
/** /**
* icmp_sock_handler() - Handle new data from ICMP or ICMPv6 socket * icmp_sock_handler() - Handle new data from ICMP or ICMPv6 socket
@ -67,8 +60,8 @@ static struct icmp_id_sock icmp_id_map[IP_VERSIONS][ICMP_NUM_IDS];
*/ */
void icmp_sock_handler(const struct ctx *c, sa_family_t af, union epoll_ref ref) void icmp_sock_handler(const struct ctx *c, sa_family_t af, union epoll_ref ref)
{ {
struct icmp_id_sock *const id_sock = af == AF_INET struct icmp_ping_flow *pingf = af == AF_INET
? &icmp_id_map[V4][ref.icmp.id] : &icmp_id_map[V6][ref.icmp.id]; ? icmp_id_map[V4][ref.icmp.id] : icmp_id_map[V6][ref.icmp.id];
const char *const pname = af == AF_INET ? "ICMP" : "ICMPv6"; const char *const pname = af == AF_INET ? "ICMP" : "ICMPv6";
union sockaddr_inany sr; union sockaddr_inany sr;
socklen_t sl = sizeof(sr); socklen_t sl = sizeof(sr);
@ -79,6 +72,8 @@ void icmp_sock_handler(const struct ctx *c, sa_family_t af, union epoll_ref ref)
if (c->no_icmp) if (c->no_icmp)
return; return;
ASSERT(pingf);
n = recvfrom(ref.fd, buf, sizeof(buf), 0, &sr.sa, &sl); n = recvfrom(ref.fd, buf, sizeof(buf), 0, &sr.sa, &sl);
if (n < 0) { if (n < 0) {
warn("%s: recvfrom() error on ping socket: %s", warn("%s: recvfrom() error on ping socket: %s",
@ -113,10 +108,10 @@ void icmp_sock_handler(const struct ctx *c, sa_family_t af, union epoll_ref ref)
/* In PASTA mode, we'll get any reply we send, discard them. */ /* In PASTA mode, we'll get any reply we send, discard them. */
if (c->mode == MODE_PASTA) { if (c->mode == MODE_PASTA) {
if (id_sock->seq == seq) if (pingf->seq == seq)
return; return;
id_sock->seq = seq; pingf->seq = seq;
} }
debug("%s: echo reply to tap, ID: %"PRIu16", seq: %"PRIu16, pname, debug("%s: echo reply to tap, ID: %"PRIu16", seq: %"PRIu16, pname,
@ -133,36 +128,52 @@ unexpected:
} }
/** /**
* icmp_ping_close() - Close and clean up a ping socket * icmp_ping_close() - Close and clean up a ping flow
* @c: Execution context * @c: Execution context
* @id_sock: Socket number and other info * @pingf: ping flow entry to close
*/ */
static void icmp_ping_close(const struct ctx *c, struct icmp_id_sock *id_sock) static void icmp_ping_close(const struct ctx *c,
const struct icmp_ping_flow *pingf)
{ {
epoll_ctl(c->epollfd, EPOLL_CTL_DEL, id_sock->sock, NULL); uint16_t id = pingf->id;
close(id_sock->sock);
id_sock->sock = -1; epoll_ctl(c->epollfd, EPOLL_CTL_DEL, pingf->sock, NULL);
id_sock->seq = -1; close(pingf->sock);
if (pingf->f.type == FLOW_PING4)
icmp_id_map[V4][id] = NULL;
else
icmp_id_map[V6][id] = NULL;
} }
/** /**
* icmp_ping_new() - Prepare a new ping socket for a new id * icmp_ping_new() - Prepare a new ping socket for a new id
* @c: Execution context * @c: Execution context
* @id_sock: Socket fd and other information * @id_sock: Pointer to ping flow entry slot in icmp_id_map[] to update
* @af: Address family, AF_INET or AF_INET6 * @af: Address family, AF_INET or AF_INET6
* @id: ICMP id for the new socket * @id: ICMP id for the new socket
* *
* Return: Newly opened ping socket fd, or -1 on failure * Return: Newly opened ping flow, or NULL on failure
*/ */
static int icmp_ping_new(const struct ctx *c, struct icmp_id_sock *id_sock, static struct icmp_ping_flow *icmp_ping_new(const struct ctx *c,
struct icmp_ping_flow **id_sock,
sa_family_t af, uint16_t id) sa_family_t af, uint16_t id)
{ {
uint8_t proto = af == AF_INET ? IPPROTO_ICMP : IPPROTO_ICMPV6;
const char *const pname = af == AF_INET ? "ICMP" : "ICMPv6"; const char *const pname = af == AF_INET ? "ICMP" : "ICMPv6";
uint8_t flowtype = af == AF_INET ? FLOW_PING4 : FLOW_PING6;
union icmp_epoll_ref iref = { .id = id }; union icmp_epoll_ref iref = { .id = id };
union flow *flow = flow_alloc();
struct icmp_ping_flow *pingf;
const void *bind_addr; const void *bind_addr;
const char *bind_if; const char *bind_if;
int s;
if (!flow)
return NULL;
pingf = FLOW_START(flow, flowtype, ping, TAPSIDE);
pingf->seq = -1;
pingf->id = id;
if (af == AF_INET) { if (af == AF_INET) {
bind_addr = &c->ip4.addr_out; bind_addr = &c->ip4.addr_out;
@ -172,28 +183,28 @@ static int icmp_ping_new(const struct ctx *c, struct icmp_id_sock *id_sock,
bind_if = c->ip6.ifname_out; bind_if = c->ip6.ifname_out;
} }
s = sock_l4(c, af, proto, bind_addr, bind_if, 0, iref.u32); pingf->sock = sock_l4(c, af, flow_proto[flowtype], bind_addr, bind_if,
0, iref.u32);
if (s < 0) { if (pingf->sock < 0) {
warn("Cannot open \"ping\" socket. You might need to:"); warn("Cannot open \"ping\" socket. You might need to:");
warn(" sysctl -w net.ipv4.ping_group_range=\"0 2147483647\""); warn(" sysctl -w net.ipv4.ping_group_range=\"0 2147483647\"");
warn("...echo requests/replies will fail."); warn("...echo requests/replies will fail.");
goto cancel; goto cancel;
} }
if (s > FD_REF_MAX) if (pingf->sock > FD_REF_MAX)
goto cancel; goto cancel;
id_sock->sock = s; *id_sock = pingf;
debug("%s: new socket %i for echo ID %"PRIu16, pname, s, id); debug("%s: new socket %i for echo ID %"PRIu16, pname, pingf->sock, id);
return s; return pingf;
cancel: cancel:
if (s >= 0) flow_alloc_cancel(flow);
close(s); return NULL;
return -1;
} }
/** /**
@ -215,14 +226,13 @@ int icmp_tap_handler(const struct ctx *c, uint8_t pif, sa_family_t af,
const char *const pname = af == AF_INET ? "ICMP" : "ICMPv6"; const char *const pname = af == AF_INET ? "ICMP" : "ICMPv6";
union sockaddr_inany sa = { .sa_family = af }; union sockaddr_inany sa = { .sa_family = af };
const socklen_t sl = af == AF_INET ? sizeof(sa.sa4) : sizeof(sa.sa6); const socklen_t sl = af == AF_INET ? sizeof(sa.sa4) : sizeof(sa.sa6);
struct icmp_id_sock *id_sock; struct icmp_ping_flow *pingf, **id_sock;
uint16_t id, seq; uint16_t id, seq;
size_t plen; size_t plen;
void *pkt; void *pkt;
int s;
(void)saddr; (void)saddr;
(void)pif; ASSERT(pif == PIF_TAP);
if (af == AF_INET) { if (af == AF_INET) {
const struct icmphdr *ih; const struct icmphdr *ih;
@ -261,13 +271,13 @@ int icmp_tap_handler(const struct ctx *c, uint8_t pif, sa_family_t af,
ASSERT(0); ASSERT(0);
} }
if ((s = id_sock->sock) < 0) if (!(pingf = *id_sock))
if ((s = icmp_ping_new(c, id_sock, af, id)) < 0) if (!(pingf = icmp_ping_new(c, id_sock, af, id)))
return 1; return 1;
id_sock->ts = now->tv_sec; pingf->ts = now->tv_sec;
if (sendto(s, pkt, plen, MSG_NOSIGNAL, &sa.sa, sl) < 0) { if (sendto(pingf->sock, pkt, plen, MSG_NOSIGNAL, &sa.sa, sl) < 0) {
debug("%s: failed to relay request to socket: %s", debug("%s: failed to relay request to socket: %s",
pname, strerror(errno)); pname, strerror(errno));
} else { } else {
@ -279,44 +289,21 @@ int icmp_tap_handler(const struct ctx *c, uint8_t pif, sa_family_t af,
} }
/** /**
* icmp_timer_one() - Handler for timed events related to a given identifier * icmp_ping_timer() - Handler for timed events related to a given flow
* @c: Execution context * @c: Execution context
* @id_sock: Socket fd and activity timestamp * @flow: flow table entry to check for timeout
* @now: Current timestamp * @now: Current timestamp
*
* Return: true if the flow is ready to free, false otherwise
*/ */
static void icmp_timer_one(const struct ctx *c, struct icmp_id_sock *id_sock, bool icmp_ping_timer(const struct ctx *c, union flow *flow,
const struct timespec *now) const struct timespec *now)
{ {
if (id_sock->sock < 0 || now->tv_sec - id_sock->ts <= ICMP_ECHO_TIMEOUT) const struct icmp_ping_flow *pingf = &flow->ping;
return;
icmp_ping_close(c, id_sock); if (now->tv_sec - pingf->ts <= ICMP_ECHO_TIMEOUT)
} return false;
/** icmp_ping_close(c, pingf);
* icmp_timer() - Scan activity bitmap for identifiers with timed events return true;
* @c: Execution context
* @now: Current timestamp
*/
void icmp_timer(const struct ctx *c, const struct timespec *now)
{
unsigned int i;
for (i = 0; i < ICMP_NUM_IDS; i++) {
icmp_timer_one(c, &icmp_id_map[V4][i], now);
icmp_timer_one(c, &icmp_id_map[V6][i], now);
}
}
/**
* icmp_init() - Initialise sequences in ID map to -1 (no sequence sent yet)
*/
void icmp_init(void)
{
unsigned i;
for (i = 0; i < ICMP_NUM_IDS; i++) {
icmp_id_map[V4][i].seq = icmp_id_map[V6][i].seq = -1;
icmp_id_map[V4][i].sock = icmp_id_map[V6][i].sock = -1;
}
} }

2
icmp.h
View file

@ -9,12 +9,12 @@
#define ICMP_TIMER_INTERVAL 10000 /* ms */ #define ICMP_TIMER_INTERVAL 10000 /* ms */
struct ctx; struct ctx;
struct icmp_ping_flow;
void icmp_sock_handler(const struct ctx *c, sa_family_t af, union epoll_ref ref); void icmp_sock_handler(const struct ctx *c, sa_family_t af, union epoll_ref ref);
int icmp_tap_handler(const struct ctx *c, uint8_t pif, sa_family_t af, int icmp_tap_handler(const struct ctx *c, uint8_t pif, sa_family_t af,
const void *saddr, const void *daddr, const void *saddr, const void *daddr,
const struct pool *p, const struct timespec *now); const struct pool *p, const struct timespec *now);
void icmp_timer(const struct ctx *c, const struct timespec *now);
void icmp_init(void); void icmp_init(void);
/** /**

31
icmp_flow.h Normal file
View file

@ -0,0 +1,31 @@
/* SPDX-License-Identifier: GPL-2.0-or-later
* Copyright Red Hat
* Author: David Gibson <david@gibson.dropbear.id.au>
*
* ICMP flow tracking data structures
*/
#ifndef ICMP_FLOW_H
#define ICMP_FLOW_H
/**
* struct icmp_ping_flow - Descriptor for a flow of ping requests/replies
* @f: Generic flow information
* @seq: Last sequence number sent to tap, host order, -1: not sent yet
* @sock: "ping" socket
* @ts: Last associated activity from tap, seconds
* @id: ICMP id for the flow as seen by the guest
*/
struct icmp_ping_flow {
/* Must be first element */
struct flow_common f;
int seq;
int sock;
time_t ts;
uint16_t id;
};
bool icmp_ping_timer(const struct ctx *c, union flow *flow,
const struct timespec *now);
#endif /* ICMP_FLOW_H */

5
passt.c
View file

@ -106,8 +106,6 @@ static void post_handler(struct ctx *c, const struct timespec *now)
CALL_PROTO_HANDLER(c, now, tcp, TCP); CALL_PROTO_HANDLER(c, now, tcp, TCP);
/* NOLINTNEXTLINE(bugprone-branch-clone): intervals can be the same */ /* NOLINTNEXTLINE(bugprone-branch-clone): intervals can be the same */
CALL_PROTO_HANDLER(c, now, udp, UDP); CALL_PROTO_HANDLER(c, now, udp, UDP);
/* NOLINTNEXTLINE(bugprone-branch-clone): intervals can be the same */
CALL_PROTO_HANDLER(c, now, icmp, ICMP);
flow_defer_handler(c, now); flow_defer_handler(c, now);
#undef CALL_PROTO_HANDLER #undef CALL_PROTO_HANDLER
@ -288,9 +286,6 @@ int main(int argc, char **argv)
if ((!c.no_udp && udp_init(&c)) || (!c.no_tcp && tcp_init(&c))) if ((!c.no_udp && udp_init(&c)) || (!c.no_tcp && tcp_init(&c)))
exit(EXIT_FAILURE); exit(EXIT_FAILURE);
if (!c.no_icmp)
icmp_init();
proto_update_l2_buf(c.mac_guest, c.mac); proto_update_l2_buf(c.mac_guest, c.mac);
if (c.ifi4 && !c.no_dhcp) if (c.ifi4 && !c.no_dhcp)