From 322660b0b931e5fc1873659182559284e7a0946a Mon Sep 17 00:00:00 2001 From: David Gibson Date: Tue, 16 Jan 2024 16:16:18 +1100 Subject: [PATCH] icmp: Dedicated functions for starting and closing ping sequences ICMP sockets are cleaned up on a timeout implemented in icmp_timer_one(), and the logic to do that cleanup is open coded in that function. Similarly new sockets are opened when we discover we don't have an existing one in icmp_tap_handler(), and again the logic is open-coded. That's not the worst thing, but it's a bit cleaner to have dedicated functions for the creation and destruction of ping sockets. This will also make things a bit easier for future changes we have in mind. Signed-off-by: David Gibson Signed-off-by: Stefano Brivio --- icmp.c | 102 +++++++++++++++++++++++++++++++++++++-------------------- 1 file changed, 67 insertions(+), 35 deletions(-) diff --git a/icmp.c b/icmp.c index a9dc436..9434fc5 100644 --- a/icmp.c +++ b/icmp.c @@ -133,6 +133,70 @@ unexpected: warn("%s: Unexpected packet on ping socket", pname); } +/** + * icmp_ping_close() - Close and clean up a ping socket + * @c: Execution context + * @id_sock: Socket number and other info + */ +static void icmp_ping_close(const struct ctx *c, struct icmp_id_sock *id_sock) +{ + epoll_ctl(c->epollfd, EPOLL_CTL_DEL, id_sock->sock, NULL); + close(id_sock->sock); + id_sock->sock = -1; + id_sock->seq = -1; +} + +/** + * icmp_ping_new() - Prepare a new ping socket for a new id + * @c: Execution context + * @id_sock: Socket fd and other information + * @af: Address family, AF_INET or AF_INET6 + * @id: ICMP id for the new socket + * + * Return: Newly opened ping socket fd, or -1 on failure + */ +static int icmp_ping_new(const struct ctx *c, struct icmp_id_sock *id_sock, + int af, uint16_t id) +{ + uint8_t proto = af == AF_INET ? IPPROTO_ICMP : IPPROTO_ICMPV6; + const char *const pname = af == AF_INET ? "ICMP" : "ICMPv6"; + union icmp_epoll_ref iref = { .id = id }; + const void *bind_addr; + const char *bind_if; + int s; + + if (af == AF_INET) { + bind_addr = &c->ip4.addr_out; + bind_if = c->ip4.ifname_out; + } else { + bind_addr = &c->ip6.addr_out; + bind_if = c->ip6.ifname_out; + } + + s = sock_l4(c, af, proto, bind_addr, bind_if, 0, iref.u32); + + if (s < 0) { + warn("Cannot open \"ping\" socket. You might need to:"); + warn(" sysctl -w net.ipv4.ping_group_range=\"0 2147483647\""); + warn("...echo requests/replies will fail."); + goto cancel; + } + + if (s > FD_REF_MAX) + goto cancel; + + id_sock->sock = s; + + debug("%s: new socket %i for echo ID %"PRIu16, pname, s, id); + + return s; + +cancel: + if (s >= 0) + close(s); + return -1; +} + /** * icmp_tap_handler() - Handle packets from tap * @c: Execution context @@ -149,7 +213,6 @@ int icmp_tap_handler(const struct ctx *c, uint8_t pif, int af, const void *saddr, const void *daddr, const struct pool *p, const struct timespec *now) { - uint8_t proto = af == AF_INET ? IPPROTO_ICMP : IPPROTO_ICMPV6; const char *const pname = af == AF_INET ? "ICMP" : "ICMPv6"; union { struct sockaddr sa; @@ -203,37 +266,9 @@ int icmp_tap_handler(const struct ctx *c, uint8_t pif, int af, ASSERT(0); } - if ((s = id_sock->sock) < 0) { - union icmp_epoll_ref iref = { .id = id }; - const void *bind_addr; - const char *bind_if; - - if (af == AF_INET) { - bind_addr = &c->ip4.addr_out; - bind_if = c->ip4.ifname_out; - } else { - bind_addr = &c->ip6.addr_out; - bind_if = c->ip6.ifname_out; - } - - s = sock_l4(c, af, proto, bind_addr, bind_if, 0, iref.u32); - - if (s < 0) { - warn("Cannot open \"ping\" socket. You might need to:"); - warn(" sysctl -w net.ipv4.ping_group_range=\"0 2147483647\""); - warn("...echo requests/replies will fail."); + if ((s = id_sock->sock) < 0) + if ((s = icmp_ping_new(c, id_sock, af, id)) < 0) return 1; - } - - if (s > FD_REF_MAX) { - close(s); - return 1; - } - - id_sock->sock = s; - - debug("%s: new socket %i for echo ID %"PRIu16, pname, s, id); - } id_sock->ts = now->tv_sec; @@ -260,10 +295,7 @@ static void icmp_timer_one(const struct ctx *c, struct icmp_id_sock *id_sock, if (id_sock->sock < 0 || now->tv_sec - id_sock->ts <= ICMP_ECHO_TIMEOUT) return; - epoll_ctl(c->epollfd, EPOLL_CTL_DEL, id_sock->sock, NULL); - close(id_sock->sock); - id_sock->sock = -1; - id_sock->seq = -1; + icmp_ping_close(c, id_sock); } /**