While working on backporting some code from *unix to android i faced the: request for member 's_addr' in mreq.imr_interface.s_addr not a structure or union”.

the relevant part of my code is:

struct ip_mreq_source mreq;

/* Set up the connection to the group */
mreq.imr_interface.s_addr = htonl(INADDR_ANY);
mreq.imr_multiaddr.s_addr = inet_addr(mcast_group);
mreq.imr_sourceaddr.s_addr = inet_addr(ssm_source);

After digging in the issue, i noted a big difference between the way the struct ip_mreq_source is declared in windows/linux and android.

on windows (winsock) and linux (netinit/in.h) the structs for setting up multicast requests and source specific multicasts requests are defined as follow:

struct ip_mreq {
struct in_addr imr_multiaddr;
struct in_addr imr_interface;
};

struct ip_mreq_source {
struct in_addr imr_multiaddr;
struct in_addr imr_sourceaddr;
struct in_addr imr_interface;
};

on bionic instead, inside of linux/in.h we have the following:

struct ip_mreq {
/* WARNING: DO NOT EDIT, AUTO-GENERATED CODE - SEE TOP FOR INSTRUCTIONS */
struct in_addr imr_multiaddr;
struct in_addr imr_interface;
};

struct ip_mreq_source {
/* WARNING: DO NOT EDIT, AUTO-GENERATED CODE - SEE TOP FOR INSTRUCTIONS */
__be32 imr_multiaddr;
__be32 imr_interface;
__be32 imr_sourceaddr;
};

as you can see ip_mreq is perfectly the same (and compatible) while for some reasons, ip_mreq_source is not.

ip_mreq_source should be re-defined as:

struct ip_mreq_source {
struct in_addr imr_multiaddr;
struct in_addr imr_sourceaddr;
struct in_addr imr_interface;
};

Issue 36987220

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