diff options
| author | Jakub Kicinski <kuba@kernel.org> | 2025-07-25 15:30:01 -0700 |
|---|---|---|
| committer | Jakub Kicinski <kuba@kernel.org> | 2025-07-25 15:30:01 -0700 |
| commit | fad4df29c2d1d5cd634ebc9121b6f5dd8becd44b (patch) | |
| tree | 42822830930e01c3c7508896b4dbb7d3297715ec | |
| parent | 4020b7bafbb720c5ee5317ef395a7547aaddc67b (diff) | |
| parent | 511d10b4c2f91fb6aa676006b2bdff4df5d6e270 (diff) | |
Merge branch 'net-add-sockaddr_inet-unified-address-structure'
Kees Cook says:
====================
net: Add sockaddr_inet unified address structure
Repeating patch 1, as it has the rationale:
There are cases in networking (e.g. wireguard, sctp) where a union is
used to provide coverage for either IPv4 or IPv6 network addresses,
and they include an embedded "struct sockaddr" as well (for "sa_family"
and raw "sa_data" access). The current struct sockaddr contains a
flexible array, which means these unions should not be further embedded
in other structs because they do not technically have a fixed size (and
are generating warnings for the coming -Wflexible-array-not-at-end flag
addition). But the future changes to make struct sockaddr a fixed size
(i.e. with a 14 byte sa_data member) make the "sa_data" uses with an IPv6
address a potential place for the compiler to get upset about object size
mismatches. Therefore, we need a sockaddr that cleanly provides both an
sa_family member and an appropriately fixed-sized sa_data member that does
not bloat member usage via the potential alternative of sockaddr_storage
to cover both IPv4 and IPv6, to avoid unseemly churn in the affected code
bases.
Introduce sockaddr_inet as a unified structure for holding both IPv4 and
IPv6 addresses (i.e. large enough to accommodate sockaddr_in6).
The structure is defined in linux/in6.h since its max size is sized
based on sockaddr_in6 and provides a more specific alternative to the
generic sockaddr_storage for IPv4 with IPv6 address family handling.
The "sa_family" member doesn't use the sa_family_t type to avoid needing
layer violating header inclusions.
Also includes the replacements for wireguard and sctp.
====================
Link: https://patch.msgid.link/20250722171528.work.209-kees@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
| -rw-r--r-- | drivers/net/wireguard/peer.h | 2 | ||||
| -rw-r--r-- | include/linux/in6.h | 7 | ||||
| -rw-r--r-- | include/net/sctp/structs.h | 2 |
3 files changed, 9 insertions, 2 deletions
diff --git a/drivers/net/wireguard/peer.h b/drivers/net/wireguard/peer.h index 76e4d3128ad4..718fb42bdac7 100644 --- a/drivers/net/wireguard/peer.h +++ b/drivers/net/wireguard/peer.h @@ -20,7 +20,7 @@ struct wg_device; struct endpoint { union { - struct sockaddr addr; + struct sockaddr_inet addr; /* Large enough for both address families */ struct sockaddr_in addr4; struct sockaddr_in6 addr6; }; diff --git a/include/linux/in6.h b/include/linux/in6.h index 0777a21cbf86..403f926d33d8 100644 --- a/include/linux/in6.h +++ b/include/linux/in6.h @@ -18,6 +18,13 @@ #include <uapi/linux/in6.h> +/* Large enough to hold both sockaddr_in and sockaddr_in6. */ +struct sockaddr_inet { + unsigned short sa_family; + char sa_data[sizeof(struct sockaddr_in6) - + sizeof(unsigned short)]; +}; + /* IPv6 Wildcard Address (::) and Loopback Address (::1) defined in RFC2553 * NOTE: Be aware the IN6ADDR_* constants and in6addr_* externals are defined * in network byte order, not in host byte order as are the IPv4 equivalents diff --git a/include/net/sctp/structs.h b/include/net/sctp/structs.h index 1ad7ce71d0a7..8a540ad9b509 100644 --- a/include/net/sctp/structs.h +++ b/include/net/sctp/structs.h @@ -51,9 +51,9 @@ * We should wean ourselves off this. */ union sctp_addr { + struct sockaddr_inet sa; /* Large enough for both address families */ struct sockaddr_in v4; struct sockaddr_in6 v6; - struct sockaddr sa; }; /* Forward declarations for data structures. */ |