Fix: casts between mbed::SocketAdrress * and struct sockaddr * cause memory overwrites due to different memory size and layout

[aentinger]

OPC/UA

struct sockaddr {
    SocketAddress ai;
};

struct addrinfo {
    SocketAddress ai;
    int     ai_flags;
    int     ai_family;
    int     ai_socktype;
    int     ai_protocol;
    size_t  ai_addrlen;
    struct  sockaddr *ai_addr;
    char    *ai_canonname;     /* canonical name */
    struct  addrinfo *ai_next; /* this struct can form a linked list */
};

MBED: SocketAddress

[aentinger]

Hi @facchinm ☕ 👋

auto rc = NetworkInterface::get_default_instance()->getaddrinfo(hostname, &mbed_hints, &mbed_res);

fails with NSAPI_ERROR_DNS_FAILURE (-3009) and has done so even before this PR.

The difference to before is that the return value of the function was previously not evaluated and always a result of 127.0.0.1 returned.

5204ec4 is a very quick fix that returns the previous functionality (no DNS lookup, assume 127.0.0.1) - however this is not desirable for the long run.

Do you have any idea what could be causing this issue (or a possible resolution)?

[github-actions]

Memory usage change @ a4cf7ab

Board	flash	%	RAM for global variables	%
arduino:mbed_opta:opta	0 - 0	0.0 - 0.0	0 - 0	0.0 - 0.0

Click for full report table

Board	examples/opcua_server flash	%	examples/opcua_server RAM for global variables	%
arduino:mbed_opta:opta	0	0.0	0	0.0

Click for full report CSV

Board,examples/opcua_server<br>flash,%,examples/opcua_server<br>RAM for global variables,%
arduino:mbed_opta:opta,0,0.0,0,0.0