+
+
+/*************************************************
+* Lookup address family of potential socket *
+*************************************************/
+
+/* Given a file-descriptor, check to see if it's a socket and, if so,
+return the address family; detects IPv4 vs IPv6. If not a socket then
+return -1.
+
+The value 0 is typically AF_UNSPEC, which should not be seen on a connected
+fd. If the return is -1, the errno will be from getsockname(); probably
+ENOTSOCK or ECONNRESET.
+
+Arguments: socket-or-not fd
+Returns: address family or -1
+*/
+
+int
+ip_get_address_family(int fd)
+{
+struct sockaddr_storage ss;
+socklen_t sslen = sizeof(ss);
+
+if (getsockname(fd, (struct sockaddr *) &ss, &sslen) < 0)
+ return -1;
+
+return (int) ss.ss_family;
+}
+
+
+
+
+/*************************************************
+* Lookup DSCP settings for a socket *
+*************************************************/
+
+struct dscp_name_tableentry {
+ const uschar *name;
+ int value;
+};
+/* Keep both of these tables sorted! */
+static struct dscp_name_tableentry dscp_table[] = {
+#ifdef IPTOS_DSCP_AF11
+ { CUS"af11", IPTOS_DSCP_AF11 },
+ { CUS"af12", IPTOS_DSCP_AF12 },
+ { CUS"af13", IPTOS_DSCP_AF13 },
+ { CUS"af21", IPTOS_DSCP_AF21 },
+ { CUS"af22", IPTOS_DSCP_AF22 },
+ { CUS"af23", IPTOS_DSCP_AF23 },
+ { CUS"af31", IPTOS_DSCP_AF31 },
+ { CUS"af32", IPTOS_DSCP_AF32 },
+ { CUS"af33", IPTOS_DSCP_AF33 },
+ { CUS"af41", IPTOS_DSCP_AF41 },
+ { CUS"af42", IPTOS_DSCP_AF42 },
+ { CUS"af43", IPTOS_DSCP_AF43 },
+ { CUS"ef", IPTOS_DSCP_EF },
+#endif
+#ifdef IPTOS_LOWCOST
+ { CUS"lowcost", IPTOS_LOWCOST },
+#endif
+ { CUS"lowdelay", IPTOS_LOWDELAY },
+#ifdef IPTOS_MINCOST
+ { CUS"mincost", IPTOS_MINCOST },
+#endif
+ { CUS"reliability", IPTOS_RELIABILITY },
+ { CUS"throughput", IPTOS_THROUGHPUT }
+};
+static int dscp_table_size =
+ sizeof(dscp_table) / sizeof(struct dscp_name_tableentry);
+
+/* DSCP values change by protocol family, and so do the options used for
+setsockopt(); this utility does all the lookups. It takes an unexpanded
+option string, expands it, strips off affix whitespace, then checks if it's
+a number. If all of what's left is a number, then that's how the option will
+be parsed and success/failure is a range check. If it's not all a number,
+then it must be a supported keyword.
+
+Arguments:
+ dscp_name a string, so far unvalidated
+ af address_family in use
+ level setsockopt level to use
+ optname setsockopt name to use
+ dscp_value value for dscp_name
+
+Returns: TRUE if okay to setsockopt(), else FALSE
+
+*level and *optname may be set even if FALSE is returned
+*/
+
+BOOL
+dscp_lookup(const uschar *dscp_name, int af,
+ int *level, int *optname, int *dscp_value)
+{
+uschar *dscp_lookup, *p;
+int first, last;
+long rawlong;
+
+if (af == AF_INET)
+ {
+ *level = IPPROTO_IP;
+ *optname = IP_TOS;
+ }
+#if HAVE_IPV6 && defined(IPV6_TCLASS)
+else if (af == AF_INET6)
+ {
+ *level = IPPROTO_IPV6;
+ *optname = IPV6_TCLASS;
+ }
+#endif
+else
+ {
+ DEBUG(D_transport)
+ debug_printf("Unhandled address family %d in dscp_lookup()\n", af);
+ return FALSE;
+ }
+if (!dscp_name)
+ {
+ DEBUG(D_transport)
+ debug_printf("[empty DSCP]\n");
+ return FALSE;
+ }
+dscp_lookup = expand_string(US dscp_name);
+if (dscp_lookup == NULL || *dscp_lookup == '\0')
+ return FALSE;
+
+p = dscp_lookup + Ustrlen(dscp_lookup) - 1;
+while (isspace(*p)) *p-- = '\0';
+while (isspace(*dscp_lookup) && dscp_lookup < p) dscp_lookup++;
+if (*dscp_lookup == '\0')
+ return FALSE;
+
+rawlong = Ustrtol(dscp_lookup, &p, 0);
+if (p != dscp_lookup && *p == '\0')
+ {
+ /* We have six bits available, which will end up shifted to fit in 0xFC mask.
+ RFC 2597 defines the values unshifted. */
+ if (rawlong < 0 || rawlong > 0x3F)
+ {
+ DEBUG(D_transport)
+ debug_printf("DSCP value %ld out of range, ignored.\n", rawlong);
+ return FALSE;
+ }
+ *dscp_value = rawlong << 2;
+ return TRUE;
+ }
+
+first = 0;
+last = dscp_table_size;
+while (last > first)
+ {
+ int middle = (first + last)/2;
+ int c = Ustrcmp(dscp_lookup, dscp_table[middle].name);
+ if (c == 0)
+ {
+ *dscp_value = dscp_table[middle].value;
+ return TRUE;
+ }
+ else if (c > 0)
+ first = middle + 1;
+ else
+ last = middle;
+ }
+return FALSE;
+}
+
+void
+dscp_list_to_stream(FILE *stream)
+{
+for (int i = 0; i < dscp_table_size; ++i)
+ fprintf(stream, "%s\n", dscp_table[i].name);
+}
+
+