Thread: getaddrinfo : who is right?

My man says that both

The gethostbyname*() and gethostbyaddr*() functions are obsolete.

So i decided to change them to getaddrinfo. So i tried to run

Code:

l_error=getaddrinfo(host, NULL, NULL, ServerSocketAddresses);

where host="173.194.35.145" and
static struct addrinfo **ServerSocketAddresses=NULL;
Program crushes:

Breakpoint 1, set_server_info (host=0x7fffffffe38e "173.194.35.145", port=80, addr_len=0x7fffffffdf1c) at socket_ip_client.c:38
38 l_error=getaddrinfo(host, NULL, NULL, ServerSocketAddresses);
(gdb) p host
$1 = 0x7fffffffe38e "173.194.35.145"
(gdb) n

Program received signal SIGSEGV, Segmentation fault.
0x00007ffff7ae9d1a in getaddrinfo () from /lib/x86_64-linux-gnu/libc.so.6

From documentation it seems that every parameter under rule and memory for ServerSocketAddresses supposed to be allocated inside call (that's why we have freeaddrinfo for later...)
Am i doing smth wrong or glibc does so?

getaddrinfo() will point a struct addrinfo* to the head of a linked list of results. As such, it needs a pointer to that pointer so it can modify it (in exactly the same way that you must pass an int* to a function that is meant to modify the int).

What you're doing is passing a null pointer instead of the address of a struct addrinfo*. What you want is something like:

Code:

struct addrinfo *res;
getaddrinfo(host, NULL, NULL, &res);

Now res points to the head of the list (or is NULL if the lookup was unsuccessful).

yep, thanks, found it too.