diff options
author | David Herrmann <dh.herrmann@googlemail.com> | 2015-10-16 13:05:39 +0200 |
---|---|---|
committer | David Herrmann <dh.herrmann@googlemail.com> | 2015-10-16 13:05:39 +0200 |
commit | 7a1e5abbc6e741e5b6995288c607522faa69c8b4 (patch) | |
tree | 2fd03f08cb9aa275e1846c1aa9e24aa8ec615e3d | |
parent | 8ee07361d0065a2d4ab9c4bf6aeb0893b05b2b6c (diff) | |
parent | 9c5a882b7fc256ddc0b227677fa06546f0e944a8 (diff) |
Merge pull request #1581 from teg/netlink-broadcast-leave
sd-netlink: refcount multicast groups
-rw-r--r-- | src/basic/missing.h | 4 | ||||
-rw-r--r-- | src/libsystemd/sd-netlink/netlink-internal.h | 6 | ||||
-rw-r--r-- | src/libsystemd/sd-netlink/netlink-socket.c | 155 | ||||
-rw-r--r-- | src/libsystemd/sd-netlink/sd-netlink.c | 56 |
4 files changed, 205 insertions, 16 deletions
diff --git a/src/basic/missing.h b/src/basic/missing.h index 59e835a466..5fb9951a84 100644 --- a/src/basic/missing.h +++ b/src/basic/missing.h @@ -126,6 +126,10 @@ #define SOL_NETLINK 270 #endif +#ifndef NETLINK_LIST_MEMBERSHIPS +#define NETLINK_LIST_MEMBERSHIPS 9 +#endif + #if !HAVE_DECL_PIVOT_ROOT static inline int pivot_root(const char *new_root, const char *put_old) { return syscall(SYS_pivot_root, new_root, put_old); diff --git a/src/libsystemd/sd-netlink/netlink-internal.h b/src/libsystemd/sd-netlink/netlink-internal.h index 4026e2c341..b9cb80668d 100644 --- a/src/libsystemd/sd-netlink/netlink-internal.h +++ b/src/libsystemd/sd-netlink/netlink-internal.h @@ -64,6 +64,9 @@ struct sd_netlink { struct sockaddr_nl nl; } sockaddr; + Hashmap *broadcast_group_refs; + bool broadcast_group_dont_leave:1; /* until we can rely on 4.2 */ + sd_netlink_message **rqueue; unsigned rqueue_size; size_t rqueue_allocated; @@ -124,7 +127,8 @@ int message_new_empty(sd_netlink *rtnl, sd_netlink_message **ret); int socket_open(int family); int socket_bind(sd_netlink *nl); -int socket_join_broadcast_group(sd_netlink *nl, unsigned group); +int socket_broadcast_group_ref(sd_netlink *nl, unsigned group); +int socket_broadcast_group_unref(sd_netlink *nl, unsigned group); int socket_write_message(sd_netlink *nl, sd_netlink_message *m); int socket_read_message(sd_netlink *nl); diff --git a/src/libsystemd/sd-netlink/netlink-socket.c b/src/libsystemd/sd-netlink/netlink-socket.c index 84ff7c38c9..e1b14c3ed2 100644 --- a/src/libsystemd/sd-netlink/netlink-socket.c +++ b/src/libsystemd/sd-netlink/netlink-socket.c @@ -44,6 +44,65 @@ int socket_open(int family) { return fd; } +static int broadcast_groups_get(sd_netlink *nl) { + _cleanup_free_ uint32_t *groups = NULL; + socklen_t len = 0, old_len; + unsigned i, j; + int r; + + assert(nl); + assert(nl->fd > 0); + + r = getsockopt(nl->fd, SOL_NETLINK, NETLINK_LIST_MEMBERSHIPS, NULL, &len); + if (r < 0) { + if (errno == ENOPROTOOPT) { + nl->broadcast_group_dont_leave = true; + return 0; + } else + return -errno; + } + + if (len == 0) + return 0; + + groups = new0(uint32_t, len); + if (!groups) + return -ENOMEM; + + old_len = len; + + r = getsockopt(nl->fd, SOL_NETLINK, NETLINK_LIST_MEMBERSHIPS, groups, &len); + if (r < 0) + return -errno; + + if (old_len != len) + return -EIO; + + r = hashmap_ensure_allocated(&nl->broadcast_group_refs, NULL); + if (r < 0) + return r; + + for (i = 0; i < len; i++) { + for (j = 0; j < sizeof(uint32_t) * 8; j ++) { + uint32_t offset; + unsigned group; + + offset = 1U << j; + + if (!(groups[i] & offset)) + continue; + + group = i * sizeof(uint32_t) * 8 + j + 1; + + r = hashmap_put(nl->broadcast_group_refs, UINT_TO_PTR(group), UINT_TO_PTR(1)); + if (r < 0) + return r; + } + } + + return 0; +} + int socket_bind(sd_netlink *nl) { socklen_t addrlen; int r, one = 1; @@ -63,11 +122,32 @@ int socket_bind(sd_netlink *nl) { if (r < 0) return -errno; + r = broadcast_groups_get(nl); + if (r < 0) + return r; + return 0; } +static unsigned broadcast_group_get_ref(sd_netlink *nl, unsigned group) { + assert(nl); + + return PTR_TO_UINT(hashmap_get(nl->broadcast_group_refs, UINT_TO_PTR(group))); +} -int socket_join_broadcast_group(sd_netlink *nl, unsigned group) { +static int broadcast_group_set_ref(sd_netlink *nl, unsigned group, unsigned n_ref) { + int r; + + assert(nl); + + r = hashmap_replace(nl->broadcast_group_refs, UINT_TO_PTR(group), UINT_TO_PTR(n_ref)); + if (r < 0) + return r; + + return 0; +} + +static int broadcast_group_join(sd_netlink *nl, unsigned group) { int r; assert(nl); @@ -81,6 +161,79 @@ int socket_join_broadcast_group(sd_netlink *nl, unsigned group) { return 0; } +int socket_broadcast_group_ref(sd_netlink *nl, unsigned group) { + unsigned n_ref; + int r; + + assert(nl); + + n_ref = broadcast_group_get_ref(nl, group); + + n_ref ++; + + r = hashmap_ensure_allocated(&nl->broadcast_group_refs, NULL); + if (r < 0) + return r; + + r = broadcast_group_set_ref(nl, group, n_ref); + if (r < 0) + return r; + + if (n_ref > 1) + /* not yet in the group */ + return 0; + + r = broadcast_group_join(nl, group); + if (r < 0) + return r; + + return 0; +} + +static int broadcast_group_leave(sd_netlink *nl, unsigned group) { + int r; + + assert(nl); + assert(nl->fd >= 0); + assert(group > 0); + + if (nl->broadcast_group_dont_leave) + return 0; + + r = setsockopt(nl->fd, SOL_NETLINK, NETLINK_DROP_MEMBERSHIP, &group, sizeof(group)); + if (r < 0) + return -errno; + + return 0; +} + +int socket_broadcast_group_unref(sd_netlink *nl, unsigned group) { + unsigned n_ref; + int r; + + assert(nl); + + n_ref = broadcast_group_get_ref(nl, group); + + assert(n_ref > 0); + + n_ref --; + + r = broadcast_group_set_ref(nl, group, n_ref); + if (r < 0) + return r; + + if (n_ref > 0) + /* still refs left */ + return 0; + + r = broadcast_group_leave(nl, group); + if (r < 0) + return r; + + return 0; +} + /* returns the number of bytes sent, or a negative error code */ int socket_write_message(sd_netlink *nl, sd_netlink_message *m) { union { diff --git a/src/libsystemd/sd-netlink/sd-netlink.c b/src/libsystemd/sd-netlink/sd-netlink.c index f4a0a358a9..5af28600ba 100644 --- a/src/libsystemd/sd-netlink/sd-netlink.c +++ b/src/libsystemd/sd-netlink/sd-netlink.c @@ -183,10 +183,11 @@ sd_netlink *sd_netlink_unref(sd_netlink *rtnl) { sd_event_unref(rtnl->event); while ((f = rtnl->match_callbacks)) { - LIST_REMOVE(match_callbacks, rtnl->match_callbacks, f); - free(f); + sd_netlink_remove_match(rtnl, f->type, f->callback, f->userdata); } + hashmap_free(rtnl->broadcast_group_refs); + safe_close(rtnl->fd); free(rtnl); } @@ -857,29 +858,29 @@ int sd_netlink_add_match(sd_netlink *rtnl, switch (type) { case RTM_NEWLINK: case RTM_DELLINK: - r = socket_join_broadcast_group(rtnl, RTNLGRP_LINK); + r = socket_broadcast_group_ref(rtnl, RTNLGRP_LINK); if (r < 0) return r; break; case RTM_NEWADDR: case RTM_DELADDR: - r = socket_join_broadcast_group(rtnl, RTNLGRP_IPV4_IFADDR); + r = socket_broadcast_group_ref(rtnl, RTNLGRP_IPV4_IFADDR); if (r < 0) return r; - r = socket_join_broadcast_group(rtnl, RTNLGRP_IPV6_IFADDR); + r = socket_broadcast_group_ref(rtnl, RTNLGRP_IPV6_IFADDR); if (r < 0) return r; break; case RTM_NEWROUTE: case RTM_DELROUTE: - r = socket_join_broadcast_group(rtnl, RTNLGRP_IPV4_ROUTE); + r = socket_broadcast_group_ref(rtnl, RTNLGRP_IPV4_ROUTE); if (r < 0) return r; - r = socket_join_broadcast_group(rtnl, RTNLGRP_IPV6_ROUTE); + r = socket_broadcast_group_ref(rtnl, RTNLGRP_IPV6_ROUTE); if (r < 0) return r; break; @@ -899,23 +900,50 @@ int sd_netlink_remove_match(sd_netlink *rtnl, sd_netlink_message_handler_t callback, void *userdata) { struct match_callback *c; + int r; assert_return(rtnl, -EINVAL); assert_return(callback, -EINVAL); assert_return(!rtnl_pid_changed(rtnl), -ECHILD); - /* we should unsubscribe from the broadcast groups at this point, but it is not so - trivial for a few reasons: the refcounting is a bit of a mess and not obvious - how it will look like after we add genetlink support, and it is also not possible - to query what broadcast groups were subscribed to when we inherit the socket to get - the initial refcount. The latter could indeed be done for the first 32 broadcast - groups (which incidentally is all we currently support in .socket units anyway), - but we better not rely on only ever using 32 groups. */ LIST_FOREACH(match_callbacks, c, rtnl->match_callbacks) if (c->callback == callback && c->type == type && c->userdata == userdata) { LIST_REMOVE(match_callbacks, rtnl->match_callbacks, c); free(c); + switch (type) { + case RTM_NEWLINK: + case RTM_DELLINK: + r = socket_broadcast_group_unref(rtnl, RTNLGRP_LINK); + if (r < 0) + return r; + + break; + case RTM_NEWADDR: + case RTM_DELADDR: + r = socket_broadcast_group_unref(rtnl, RTNLGRP_IPV4_IFADDR); + if (r < 0) + return r; + + r = socket_broadcast_group_unref(rtnl, RTNLGRP_IPV6_IFADDR); + if (r < 0) + return r; + + break; + case RTM_NEWROUTE: + case RTM_DELROUTE: + r = socket_broadcast_group_unref(rtnl, RTNLGRP_IPV4_ROUTE); + if (r < 0) + return r; + + r = socket_broadcast_group_unref(rtnl, RTNLGRP_IPV6_ROUTE); + if (r < 0) + return r; + break; + default: + return -EOPNOTSUPP; + } + return 1; } |