diff options
| -rw-r--r-- | src/resolve/resolved-dns-stream.c | 2 | ||||
| -rw-r--r-- | src/resolve/resolved-manager.c | 2 | ||||
| -rw-r--r-- | src/shared/macro.h | 3 | ||||
| -rw-r--r-- | src/test/test-util.c | 4 |
4 files changed, 9 insertions, 2 deletions
diff --git a/src/resolve/resolved-dns-stream.c b/src/resolve/resolved-dns-stream.c index 8b3a3ced4b..8aad5e4df1 100644 --- a/src/resolve/resolved-dns-stream.c +++ b/src/resolve/resolved-dns-stream.c @@ -64,7 +64,7 @@ static int dns_stream_complete(DnsStream *s, int error) { static int dns_stream_identify(DnsStream *s) { union { struct cmsghdr header; /* For alignment */ - uint8_t buffer[CMSG_SPACE(CONST_MAX(sizeof(struct in_pktinfo), sizeof(struct in6_pktinfo))) + uint8_t buffer[CMSG_SPACE(MAXSIZE(struct in_pktinfo, struct in6_pktinfo)) + EXTRA_CMSG_SPACE /* kernel appears to require extra space */]; } control; struct msghdr mh = {}; diff --git a/src/resolve/resolved-manager.c b/src/resolve/resolved-manager.c index 56baf8730d..659b1dacc8 100644 --- a/src/resolve/resolved-manager.c +++ b/src/resolve/resolved-manager.c @@ -841,7 +841,7 @@ int manager_recv(Manager *m, int fd, DnsProtocol protocol, DnsPacket **ret) { _cleanup_(dns_packet_unrefp) DnsPacket *p = NULL; union { struct cmsghdr header; /* For alignment */ - uint8_t buffer[CMSG_SPACE(CONST_MAX(sizeof(struct in_pktinfo), sizeof(struct in6_pktinfo))) + uint8_t buffer[CMSG_SPACE(MAXSIZE(struct in_pktinfo, struct in6_pktinfo)) + CMSG_SPACE(int) /* ttl/hoplimit */ + EXTRA_CMSG_SPACE /* kernel appears to require extra buffer space */]; } control; diff --git a/src/shared/macro.h b/src/shared/macro.h index 179b24c983..43fa3e556f 100644 --- a/src/shared/macro.h +++ b/src/shared/macro.h @@ -149,6 +149,9 @@ static inline unsigned long ALIGN_POWER2(unsigned long u) { ((_A) > (_B)) ? (_A) : (_B), \ (void)0)) +/* takes two types and returns the size of the larger one */ +#define MAXSIZE(A, B) (sizeof(union _packed_ { typeof(A) a; typeof(B) b; })) + #define MAX3(x,y,z) \ __extension__ ({ \ const typeof(x) _c = MAX(x,y); \ diff --git a/src/test/test-util.c b/src/test/test-util.c index ac1afce86b..34d5f2ed7d 100644 --- a/src/test/test-util.c +++ b/src/test/test-util.c @@ -90,6 +90,10 @@ static void test_max(void) { assert_se(val1.a == 100); assert_se(MAX(++d, 0) == 1); assert_se(d == 1); + + assert_cc(MAXSIZE(char[3], uint16_t) == 3); + assert_cc(MAXSIZE(char[3], uint32_t) == 4); + assert_cc(MAXSIZE(char, long) == sizeof(long)); } static void test_first_word(void) { |