Original bug ID: 3565
Reporter: administrator
Status: closed
Resolution: fixed
Priority: normal
Severity: minor
Category: ~DO NOT USE (was: OCaml general)

Bug description

Full_Name: Samuel Thibault
Version: 3.08.3
OS: Linux
Submission from: d83-177-178-162.cust.tele2.fr (83.177.178.162)

Hi,

While trying to use ipv6 with Ocaml, getaddrinfo returned me strange results. My
/etc/hosts contains
fec0::2d0:59ff:fe4b:1b2e interface.ipv6
and ping6 interface.ipv6 does work, so C resolving works, but:

open Unix;;

let [ ai ] = getaddrinfo "interface.ipv6" "12345" [AI_SOCKTYPE SOCK_STREAM];;

Warning: this pattern-matching is not exhaustive.
Here is an example of a value that is not matched:
[]
val ai : Unix.addr_info =
{ai_family = PF_INET6; ai_socktype = SOCK_STREAM; ai_protocol = 6;
ai_addr = ADDR_INET (, 12345); ai_canonname = ""}

let ADDR_INET(adr,port) = ai.ai_addr;;

Warning: this pattern-matching is not exhaustive.
Here is an example of a value that is not matched:
ADDR_UNIX _
val adr : Unix.inet_addr =
val port : int = 12345

string_of_inet_addr adr;;

• : string = "fec0::90e8:ffbf:200:0"

Which is just garbage. In otherlibs/unix/getaddrinfo.c, I noticed the following
lines in convert_addrinfo():
memcpy(&sa.s_gen, a->ai_addr, sizeof(struct sockaddr));
vaddr = alloc_sockaddr(&sa, sizeof(struct sockaddr), -1);
This is wrong: struct sockaddr is not always big enough to hold struct
sockaddr_in6 for instance. sizeof(struct sockaddr) should be replaced by
a->ai_addrlen for instance (after checking that this is smaller than caml's
sizeof(union sock_addr_union) ), in which case it does work:

open Unix;;

let [ ai ] = getaddrinfo "interface.ipv6" "12345" [AI_SOCKTYPE SOCK_STREAM];;

Warning: this pattern-matching is not exhaustive.
Here is an example of a value that is not matched:
[]
val ai : Unix.addr_info =
{ai_family = PF_INET6; ai_socktype = SOCK_STREAM; ai_protocol = 6;
ai_addr = ADDR_INET (, 12345); ai_canonname = ""}

let ADDR_INET(adr,port) = ai.ai_addr;;

Warning: this pattern-matching is not exhaustive.
Here is an example of a value that is not matched:
ADDR_UNIX _
val adr : Unix.inet_addr =
val port : int = 12345

string_of_inet_addr adr;;

• : string = "fec0::2d0:59ff:fe4b:1b2e"

Regards,
Samuel Thibault