1 files changed, 171 insertions, 0 deletions
diff --git a/pgm4/inet_addrs.d/getaddrs.c b/pgm4/inet_addrs.d/getaddrs.c
new file mode 100644
index 0000000..f229662
--- /dev/null
+++ b/pgm4/inet_addrs.d/getaddrs.c
@@ -0,0 +1,171 @@
+// Using getaddrinfo() to get IPv4 address for
+// hostname (argv[1]) and service (argv[2]).
+//
+// The print_XXX() functions are from Stevens
+// and Rago.
+//
+// P. Kearns, February 2009
+
+
+#include <netdb.h>
+#include <sys/socket.h>
+#include <arpa/inet.h>
+#include <netinet/in.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+
+void
+print_family(struct addrinfo *aip)
+{
+    printf(" family ");
+    switch (aip->ai_family) {
+    case AF_INET:
+        printf("inet");
+        break;
+    case AF_INET6:
+        printf("inet6");
+        break;
+    case AF_UNIX:
+        printf("unix");
+        break;
+    case AF_UNSPEC:
+        printf("unspecified");
+        break;
+    default:
+        printf("unknown");
+    }
+
+}
+void
+print_type(struct addrinfo *aip)
+{
+    printf(" type ");
+    switch (aip->ai_socktype) {
+    case SOCK_STREAM:
+        printf("stream");
+        break;
+    case SOCK_DGRAM:
+        printf("datagram");
+        break;
+    case SOCK_SEQPACKET:
+        printf("seqpacket");
+        break;
+    case SOCK_RAW:
+        printf("raw");
+        break;
+    default:
+        printf("unknown (%d)", aip->ai_socktype);
+    }
+}
+
+void
+print_protocol(struct addrinfo *aip)
+{
+    printf(" protocol ");
+    switch (aip->ai_protocol) {
+    case 0:
+        printf("default");
+        break;
+    case IPPROTO_TCP:
+        printf("TCP");
+        break;
+    case IPPROTO_UDP:
+        printf("UDP");
+        break;
+    case IPPROTO_RAW:
+        printf("raw");
+        break;
+    default:
+        printf("unknown (%d)", aip->ai_protocol);
+    }
+}
+
+void
+print_flags(struct addrinfo *aip)
+{
+    printf("flags");
+    if (aip->ai_flags == 0) {
+        printf(" 0");
+
+    } else {
+        if (aip->ai_flags & AI_PASSIVE)
+            printf(" passive");
+        if (aip->ai_flags & AI_CANONNAME)
+            printf(" canon");
+        if (aip->ai_flags & AI_NUMERICHOST)
+            printf(" numhost");
+#if defined(AI_NUMERICSERV)
+        if (aip->ai_flags & AI_NUMERICSERV)
+            printf(" numserv");
+#endif
+#if defined(AI_V4MAPPED)
+        if (aip->ai_flags & AI_V4MAPPED)
+            printf(" v4mapped");
+#endif
+#if defined(AI_ALL)
+        if (aip->ai_flags & AI_ALL)
+            printf(" all");
+#endif
+    }
+}
+
+int main(int argc,char **argv)
+{
+  struct addrinfo *addrlist, *aptr, hints;
+  struct sockaddr_in *saddrptr;
+  const char * p; char addrbuffer[INET_ADDRSTRLEN]; int ecode;
+
+  if(argc != 3) {
+    fprintf(stderr, "usage: getaddrs node service\n");
+    exit(1);
+  }
+
+// Want IPv4 lookup only.
+
+  memset(&hints, 0, sizeof(hints));
+  hints.ai_family = AF_INET;
+  hints.ai_socktype = 0;
+  hints.ai_flags = AI_CANONNAME;
+  hints.ai_protocol = 0;
+  hints.ai_canonname = NULL;
+  hints.ai_addr = NULL;
+  hints.ai_next = NULL;
+
+// Do the lookup.
+
+  ecode = getaddrinfo(argv[1], argv[2], &hints, &addrlist);
+  if (ecode != 0) {
+    fprintf(stderr, "getaddrinfo: %s\n", gai_strerror(ecode));
+    exit(1);
+  }
+
+// Scan the list of results.
+
+  for (aptr = addrlist; aptr != NULL; aptr = aptr->ai_next) {
+    print_flags(aptr); print_family(aptr);
+    print_type(aptr); print_protocol(aptr);
+
+    if (aptr->ai_family == AF_INET){
+      printf("\tName: %s\n", aptr->ai_canonname?aptr->ai_canonname:"none");
+
+      // Get at filled-in sockaddr_in hanging off the addrinfo.
+
+      saddrptr = (struct sockaddr_in *) aptr->ai_addr;
+      p = inet_ntop(AF_INET, &saddrptr->sin_addr.s_addr, addrbuffer, INET_ADDRSTRLEN);
+
+      if (!p) {
+        perror("inet_ntop");
+        exit(1);
+      }
+
+      printf("IP Address: %s\n", p?p:"unknown");
+      printf("Port: %d\n", ntohs(saddrptr->sin_port));
+    }
+  }
+
+  // Give back result structs (not really impt here).
+
+  freeaddrinfo(addrlist);
+  exit(0);
+}