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-rw-r--r--pgm4/inet_addrs.d/Makefile10
-rw-r--r--pgm4/inet_addrs.d/README11
-rw-r--r--pgm4/inet_addrs.d/getaddrs.c171
-rw-r--r--pgm4/inet_addrs.d/gethost.c57
4 files changed, 249 insertions, 0 deletions
diff --git a/pgm4/inet_addrs.d/Makefile b/pgm4/inet_addrs.d/Makefile
new file mode 100644
index 0000000..a10866c
--- /dev/null
+++ b/pgm4/inet_addrs.d/Makefile
@@ -0,0 +1,10 @@
+all: gethost getaddrs
+
+gethost: gethost.c
+ gcc -Wall -o gethost gethost.c
+
+getaddrs: getaddrs.c
+ gcc -Wall -o getaddrs getaddrs.c
+
+clean:
+ rm -f getaddrs gethost
diff --git a/pgm4/inet_addrs.d/README b/pgm4/inet_addrs.d/README
new file mode 100644
index 0000000..fbfb676
--- /dev/null
+++ b/pgm4/inet_addrs.d/README
@@ -0,0 +1,11 @@
+A pair of simple programs which play with symbolic and IP addresses.
+
+Invoke as:
+ getaddrs host service
+ host should be a symbolic host name
+ service should be a service name, port number, or 0
+
+ gethost ipaddr
+ ipaddr should be a dotted decimal IP address
+
+
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);
+}
diff --git a/pgm4/inet_addrs.d/gethost.c b/pgm4/inet_addrs.d/gethost.c
new file mode 100644
index 0000000..dcfc7fd
--- /dev/null
+++ b/pgm4/inet_addrs.d/gethost.c
@@ -0,0 +1,57 @@
+// Using getnameinfo() to get host name for a
+// given IP address (argv[1]).
+//
+// 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>
+
+int main(int argc, char **argv)
+{
+
+ int ecode;
+ struct in_addr fillin;
+ struct sockaddr_in addr;
+ char host[NI_MAXHOST];
+
+ if (argc != 2) {
+ fprintf(stderr,"usage: gethost address\n");
+ exit(1);
+ }
+
+// Dotted decimal to binary IP address.
+
+ ecode = inet_pton(AF_INET, argv[1], &fillin);
+ if (ecode == 0) {
+ fprintf(stderr,"inet_pton: invalid address\n");
+ exit(1);
+ }
+ if (ecode < 0) {
+ perror("inet_pton"); exit(1);
+ exit(1);
+ }
+
+// Fill in blanks of a sockaddr_in after zeroing it out.
+
+ memset(&addr, 0, sizeof(addr));
+ addr.sin_family = AF_INET;
+ addr.sin_port = htons(0);
+ memcpy(&(addr.sin_addr), &fillin, sizeof(addr.sin_addr));
+
+// Do the lookup.
+
+ ecode = getnameinfo((struct sockaddr *) &addr, sizeof(addr),
+ host, NI_MAXHOST, NULL, 0, NI_NAMEREQD);
+ if (ecode) {
+ fprintf(stderr, "getnameinfo: %s\n", gai_strerror(ecode));
+ exit(1);
+ }
+
+ printf("Hostname: %s\n", host);
+ exit(0);
+}
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