Add function to guess AF_UNSPEC address
Sometimes we receive generic "struct sockaddr" with unspecified (AF_UNSPEC)
address family. It's handy to try to guess
the proper address (there're just 2 variants ATM in most practical applications).
Use the added function to relax input checks in osmo_sockaddr_str_from_in*()
Related: OS#5581
Change-Id: I1c90c56ce832f53b65e0d18d3cea94621c02a69a
diff --git a/include/osmocom/core/sockaddr_str.h b/include/osmocom/core/sockaddr_str.h
index f474fa0..a46ad59 100644
--- a/include/osmocom/core/sockaddr_str.h
+++ b/include/osmocom/core/sockaddr_str.h
@@ -41,6 +41,7 @@
*/
int osmo_ip_str_type(const char *ip);
+unsigned osmo_sockaddr_guess_unspec(const struct sockaddr *src);
struct osmo_sockaddr_str {
/*! AF_INET for IPv4 address, or AF_INET6 for IPv6 address. */
diff --git a/src/sockaddr_str.c b/src/sockaddr_str.c
index 9f1e897..70927a7 100644
--- a/src/sockaddr_str.c
+++ b/src/sockaddr_str.c
@@ -184,6 +184,38 @@
return AF_UNSPEC;
}
+/*! Guess whether struct sockaddr with AF_UNSPEC family has valid IPv4 or IPv6 address.
+ * The IPv6 is tried first to take into account "IPv4 mapped addresses".
+ * \param[in] src Generic struct sockaddr pointer.
+ * \return AF_INET or AF_INET6, AF_UNSPEC or original sa_family which are unsigned type according to <sys/socket.h>.
+ */
+unsigned osmo_sockaddr_guess_unspec(const struct sockaddr *src)
+{
+ int rc;
+ struct osmo_sockaddr_str sa;
+ struct osmo_sockaddr_str *tmp = &sa;
+ const struct sockaddr_in6 *src6 = (const struct sockaddr_in6 *)src;
+ const struct sockaddr_in *src4 = (const struct sockaddr_in *)src;
+
+ if (!src)
+ return AF_UNSPEC;
+
+ if (src->sa_family != AF_UNSPEC)
+ return src->sa_family;
+
+ /* IPv6? */
+ rc = osmo_sockaddr_str_from_in6_addr(tmp, &src6->sin6_addr, osmo_ntohs(src6->sin6_port));
+ if (rc == 0 && osmo_ip_str_type(tmp->ip) == AF_INET6)
+ return AF_INET6;
+
+ /* IPv4? */
+ rc = osmo_sockaddr_str_from_in_addr(tmp, &src4->sin_addr, osmo_ntohs(src4->sin_port));
+ if (rc == 0 && osmo_ip_str_type(tmp->ip) == AF_INET)
+ return AF_INET;
+
+ return AF_UNSPEC;
+}
+
/*! Safely copy the given ip string to sockaddr_str, classify to AF_INET or AF_INET6.
* Data will be written to sockaddr_str even if an error is returned.
* \param[out] sockaddr_str The instance to copy to.
@@ -317,7 +349,7 @@
return -ENOSPC;
if (!src)
return -EINVAL;
- if (src->sin_family != AF_INET)
+ if (src->sin_family != AF_INET && osmo_sockaddr_guess_unspec((const struct sockaddr *)src) != AF_INET)
return -EINVAL;
return osmo_sockaddr_str_from_in_addr(sockaddr_str, &src->sin_addr, osmo_ntohs(src->sin_port));
}
@@ -333,7 +365,7 @@
return -ENOSPC;
if (!src)
return -EINVAL;
- if (src->sin6_family != AF_INET6)
+ if (src->sin6_family != AF_INET6 && osmo_sockaddr_guess_unspec((const struct sockaddr *)src) != AF_INET6)
return -EINVAL;
return osmo_sockaddr_str_from_in6_addr(sockaddr_str, &src->sin6_addr, osmo_ntohs(src->sin6_port));
}