BUILD: quic_sock: address a strict-aliasing build warning with gcc 5 and 6

The UDP GSO code emits a build warning with older toolchains (gcc 5 and 6):

  src/quic_sock.c: In function 'cmsg_set_gso':
  src/quic_sock.c:683:2: warning: dereferencing type-punned pointer will break strict-aliasing rules [-Wstrict-aliasing]
    *((uint16_t *)CMSG_DATA(c)) = gso_size;
    ^

Let's just use the write_u16() function that's made for this purpose.
It was verified that for all versions from 5 to 13, gcc produces the
exact same code with the fix (and without the warning). It arrived in
3.1 with commit 448d3d388a ("MINOR: quic: add GSO parameter on quic_sock
send API") so this can be backported there.
This commit is contained in:
Willy Tarreau 2025-04-02 16:07:31 +02:00
parent 870f7aa5cf
commit dd900aead8

View File

@ -680,7 +680,7 @@ static void cmsg_set_gso(struct msghdr *msg, struct cmsghdr **cmsg,
c->cmsg_level = SOL_UDP; c->cmsg_level = SOL_UDP;
c->cmsg_type = UDP_SEGMENT; c->cmsg_type = UDP_SEGMENT;
c->cmsg_len = CMSG_LEN(sz); c->cmsg_len = CMSG_LEN(sz);
*((uint16_t *)CMSG_DATA(c)) = gso_size; write_u16(CMSG_DATA(c), gso_size);
#endif #endif
} }