patch: use a lookup table in BIO_get_port()

[Dimitris Papastamos]

Not sure this is sensible as it encourages people to simply
update the table.

I was inclined to remove the code entirely but I am not sure
what broken systems might rely on this.

Only build tested.

Thoughts?

Index: b_sock.c
===================================================================
RCS file: /cvs/src/lib/libssl/src/crypto/bio/b_sock.c,v
retrieving revision 1.33
diff -u -p -r1.33 b_sock.c
--- b_sock.c    26 Apr 2014 18:56:37 -0000      1.33
+++ b_sock.c    29 Apr 2014 13:55:39 -0000
@@ -140,6 +140,19 @@ BIO_get_port(const char *str, unsigned s
 {
        int i;
        struct servent *s;
+       size_t len;
+       struct {
+               const char *name;
+               int port;
+       } servmap[] = {
+               { "http",   80   },
+               { "telnet", 23   },
+               { "socks",  1080 },
+               { "https",  443  },
+               { "ssl",    443  },
+               { "ftp",    21   },
+               { "gopher", 70   }
+       };
 
        if (str == NULL) {
                BIOerr(BIO_F_BIO_GET_PORT, BIO_R_NO_PORT_DEFINED);
@@ -155,21 +168,14 @@ BIO_get_port(const char *str, unsigned s
                        *port_ptr = ntohs((unsigned short)s->s_port);
                CRYPTO_w_unlock(CRYPTO_LOCK_GETSERVBYNAME);
                if (s == NULL) {
-                       if (strcmp(str, "http") == 0)
-                               *port_ptr = 80;
-                       else if (strcmp(str, "telnet") == 0)
-                               *port_ptr = 23;
-                       else if (strcmp(str, "socks") == 0)
-                               *port_ptr = 1080;
-                       else if (strcmp(str, "https") == 0)
-                               *port_ptr = 443;
-                       else if (strcmp(str, "ssl") == 0)
-                               *port_ptr = 443;
-                       else if (strcmp(str, "ftp") == 0)
-                               *port_ptr = 21;
-                       else if (strcmp(str, "gopher") == 0)
-                               *port_ptr = 70;
-                       else {
+                       len = sizeof(servmap) / sizeof(servmap[0]);
+                       for (i = 0; i < len; i++) {
+                               if (strcmp(str, servmap[i].name) == 0) {
+                                       *port_ptr = servmap[i].port;
+                                       break;
+                               }
+                       }
+                       if (i == len) {
                                SYSerr(SYS_F_GETSERVBYNAME, errno);
                                ERR_asprintf_error_data("service='%s'", str);
                                return (0);