We have different epoll type values for ICMP and ICMPv6 sockets, but they
both call the same handler function, icmp_sock_handler(). However that
function does essentially nothing in common for the two cases. So, split
it into icmp_sock_handler() and icmpv6_sock_handler() and dispatch them
separately from the top level.
While we're there remove some parameters that the function was never using
anyway. Also move the test for c->no_icmp into the functions, so that all
the logic specific to ICMP is within the handler, rather than in the top
level dispatch code.
Signed-off-by: David Gibson <david(a)gibson.dropbear.id.au>
---
icmp.c | 112 ++++++++++++++++++++++++++++++++------------------------
icmp.h | 9 ++---
passt.c | 5 ++-
3 files changed, 70 insertions(+), 56 deletions(-)
diff --git a/icmp.c b/icmp.c
index a4b6a47..b676a1a 100644
--- a/icmp.c
+++ b/icmp.c
@@ -60,78 +60,94 @@ static struct icmp_id_sock icmp_id_map[IP_VERSIONS][ICMP_NUM_IDS];
static uint8_t icmp_act[IP_VERSIONS][DIV_ROUND_UP(ICMP_NUM_IDS, 8)];
/**
- * icmp_sock_handler() - Handle new data from socket
+ * icmp_sock_handler() - Handle new data from IPv4 ICMP socket
* @c: Execution context
* @ref: epoll reference
- * @events: epoll events bitmap
- * @now: Current timestamp, unused
*/
-void icmp_sock_handler(const struct ctx *c, union epoll_ref ref,
- uint32_t events, const struct timespec *now)
+void icmp_sock_handler(const struct ctx *c, union epoll_ref ref)
{
- union icmp_epoll_ref *iref = &ref.icmp;
- struct sockaddr_storage sr;
- socklen_t sl = sizeof(sr);
char buf[USHRT_MAX];
+ struct icmphdr *ih = (struct icmphdr *)buf;
+ struct sockaddr_in sr;
+ socklen_t sl = sizeof(sr);
uint16_t seq, id;
ssize_t n;
- (void)events;
- (void)now;
+ if (c->no_icmp)
+ return;
+ /* FIXME: Workaround clang-tidy not realizing that recvfrom()
+ * writes the socket address. See
+ * https://github.com/llvm/llvm-project/issues/58992
+ */
+ memset(&sr, 0, sizeof(sr));
n = recvfrom(ref.fd, buf, sizeof(buf), 0, (struct sockaddr *)&sr, &sl);
if (n < 0)
return;
- if (iref->v6) {
- struct sockaddr_in6 *sr6 = (struct sockaddr_in6 *)&sr;
- struct icmp6hdr *ih = (struct icmp6hdr *)buf;
+ id = ntohs(ih->un.echo.id);
+ seq = ntohs(ih->un.echo.sequence);
- id = ntohs(ih->icmp6_identifier);
- seq = ntohs(ih->icmp6_sequence);
+ if (id != ref.icmp.id)
+ ih->un.echo.id = htons(ref.icmp.id);
- /* If bind() fails e.g. because of a broken SELinux policy, this
- * might happen. Fix up the identifier to match the sent one.
- */
- if (id != iref->id)
- ih->icmp6_identifier = htons(iref->id);
+ if (c->mode == MODE_PASTA) {
+ if (icmp_id_map[V4][id].seq == seq)
+ return;
- /* In PASTA mode, we'll get any reply we send, discard them. */
- if (c->mode == MODE_PASTA) {
- if (icmp_id_map[V6][id].seq == seq)
- return;
-
- icmp_id_map[V6][id].seq = seq;
- }
+ icmp_id_map[V4][id].seq = seq;
+ }
- debug("ICMPv6: echo %s to tap, ID: %i, seq: %i",
- (ih->icmp6_type == 128) ? "request" : "reply", id, seq);
+ debug("ICMP: echo %s to tap, ID: %i, seq: %i",
+ (ih->type == ICMP_ECHO) ? "request" : "reply", id, seq);
- tap_icmp6_send(c, &sr6->sin6_addr,
- tap_ip6_daddr(c, &sr6->sin6_addr), buf, n);
- } else {
- struct sockaddr_in *sr4 = (struct sockaddr_in *)&sr;
- struct icmphdr *ih = (struct icmphdr *)buf;
+ tap_icmp4_send(c, sr.sin_addr, tap_ip4_daddr(c), buf, n);
+}
- id = ntohs(ih->un.echo.id);
- seq = ntohs(ih->un.echo.sequence);
+/**
+ * icmpv6_sock_handler() - Handle new data from ICMPv6 socket
+ * @c: Execution context
+ * @ref: epoll reference
+ */
+void icmpv6_sock_handler(const struct ctx *c, union epoll_ref ref)
+{
+ char buf[USHRT_MAX];
+ struct icmp6hdr *ih = (struct icmp6hdr *)buf;
+ struct sockaddr_in6 sr;
+ socklen_t sl = sizeof(sr);
+ uint16_t seq, id;
+ ssize_t n;
- if (id != iref->id)
- ih->un.echo.id = htons(iref->id);
+ if (c->no_icmp)
+ return;
- if (c->mode == MODE_PASTA) {
+ n = recvfrom(ref.fd, buf, sizeof(buf), 0, (struct sockaddr *)&sr, &sl);
+ if (n < 0)
+ return;
- if (icmp_id_map[V4][id].seq == seq)
- return;
+ id = ntohs(ih->icmp6_identifier);
+ seq = ntohs(ih->icmp6_sequence);
- icmp_id_map[V4][id].seq = seq;
- }
+ /* If bind() fails e.g. because of a broken SELinux policy,
+ * this might happen. Fix up the identifier to match the sent
+ * one.
+ */
+ if (id != ref.icmp.id)
+ ih->icmp6_identifier = htons(ref.icmp.id);
- debug("ICMP: echo %s to tap, ID: %i, seq: %i",
- (ih->type == ICMP_ECHO) ? "request" : "reply", id, seq);
+ /* In PASTA mode, we'll get any reply we send, discard them. */
+ if (c->mode == MODE_PASTA) {
+ if (icmp_id_map[V6][id].seq == seq)
+ return;
- tap_icmp4_send(c, sr4->sin_addr, tap_ip4_daddr(c), buf, n);
+ icmp_id_map[V6][id].seq = seq;
}
+
+ debug("ICMPv6: echo %s to tap, ID: %i, seq: %i",
+ (ih->icmp6_type == 128) ? "request" : "reply", id, seq);
+
+ tap_icmp6_send(c, &sr.sin6_addr,
+ tap_ip6_daddr(c, &sr.sin6_addr), buf, n);
}
/**
@@ -150,11 +166,11 @@ int icmp_tap_handler(const struct ctx *c, int af, const void *addr,
size_t plen;
if (af == AF_INET) {
- union icmp_epoll_ref iref = { .v6 = 0 };
struct sockaddr_in sa = {
.sin_family = AF_INET,
.sin_addr = { .s_addr = htonl(INADDR_ANY) },
};
+ union icmp_epoll_ref iref;
struct icmphdr *ih;
int id, s;
@@ -204,12 +220,12 @@ int icmp_tap_handler(const struct ctx *c, int af, const void *addr,
id, ntohs(ih->un.echo.sequence));
}
} else if (af == AF_INET6) {
- union icmp_epoll_ref iref = { .v6 = 1 };
struct sockaddr_in6 sa = {
.sin6_family = AF_INET6,
.sin6_addr = IN6ADDR_ANY_INIT,
.sin6_scope_id = c->ifi6,
};
+ union icmp_epoll_ref iref;
struct icmp6hdr *ih;
int id, s;
diff --git a/icmp.h b/icmp.h
index 29c7829..32f0c47 100644
--- a/icmp.h
+++ b/icmp.h
@@ -10,8 +10,8 @@
struct ctx;
-void icmp_sock_handler(const struct ctx *c, union epoll_ref ref,
- uint32_t events, const struct timespec *now);
+void icmp_sock_handler(const struct ctx *c, union epoll_ref ref);
+void icmpv6_sock_handler(const struct ctx *c, union epoll_ref ref);
int icmp_tap_handler(const struct ctx *c, int af, const void *addr,
const struct pool *p, const struct timespec *now);
void icmp_timer(const struct ctx *c, const struct timespec *ts);
@@ -24,10 +24,7 @@ void icmp_init(void);
* @id: Associated echo identifier, needed if bind() fails
*/
union icmp_epoll_ref {
- struct {
- uint32_t v6:1,
- id:16;
- };
+ uint16_t id;
uint32_t u32;
};
diff --git a/passt.c b/passt.c
index 32ea2ca..33c2162 100644
--- a/passt.c
+++ b/passt.c
@@ -329,9 +329,10 @@ loop:
udp_sock_handler(&c, ref, eventmask, &now);
break;
case EPOLL_TYPE_ICMP:
+ icmp_sock_handler(&c, ref);
+ break;
case EPOLL_TYPE_ICMPV6:
- if (!c.no_icmp)
- icmp_sock_handler(&c, ref, eventmask, &now);
+ icmpv6_sock_handler(&c, ref);
break;
default:
/* Can't happen */
--
2.41.0