changes made after review

libc/dns/getaddrinfo.c

@@ -55,11 +55,11 @@ int getaddrinfo(const char *name, const char *service,
   if (!name && (hints->ai_flags & AI_CANONNAME)) return EAI_BADFLAGS;
   if (service) {
     if (hints->ai_socktype == SOCK_STREAM)
-      strncpy(proto, "tcp", sizeof(proto));
+      strcpy(proto, "tcp");
     else if (hints->ai_socktype == SOCK_DGRAM)
-      strncpy(proto, "udp", sizeof(proto));
+      strcpy(proto, "udp");
     else /* ai_socktype == 0 */
-      proto[0] = '\0';
+      strcpy(proto, "");
 
     if ((port = LookupServicesByName(service, proto, sizeof(proto), NULL, 0,
                                      NULL)) == -1) {

libc/dns/getservbyname.c

@@ -44,8 +44,10 @@ struct servent *getservbyname(const char *name, const char *proto) {
     ptr0 = &se0;
   }
 
-  localproto[0] = '\0';
+  if (proto) {
-  if (proto) strncpy(localproto, proto, DNS_NAME_MAX);
+    if (!memccpy(localproto, proto, '\0', DNS_NAME_MAX)) return NULL;
+  } else
+    strcpy(localproto, "");
 
   p = LookupServicesByName(name, ptr0->s_proto, DNS_NAME_MAX, ptr0->s_name,
                            DNS_NAME_MAX, NULL);

libc/dns/getservbyport.c

@@ -43,8 +43,10 @@ struct servent *getservbyport(int port, const char *proto) {
     ptr1 = &se1;
   }
 
-  localproto[0] = '\0';
+  if (proto) {
-  if (proto) strncpy(localproto, proto, DNS_NAME_MAX);
+    if (!memccpy(localproto, proto, '\0', DNS_NAME_MAX)) return NULL;
+  } else
+    strcpy(localproto, "");
 
   if (LookupServicesByPort(ntohs(port), ptr1->s_proto, DNS_NAME_MAX,
                            ptr1->s_name, DNS_NAME_MAX, NULL) == -1)

libc/dns/prototxt.c

@@ -57,11 +57,10 @@ static textwindows noinline char *GetNtProtocolsTxtPath(char *pathbuf,
  *
  * format of /etc/protocols is like this:
  *
- *      # comment
+ * # comment
- *      # NAME      PROTOCOL    ALIASES
+ * # NAME           PROTOCOL        ALIASES
- *
+ * ip               0               IP
- *      ip	        0	        IP
+ * icmp             1               ICMP
- *      icmp	    1	        ICMP
  *
  * @param protonum is the protocol number
  * @param buf is a buffer to store the official name of the protocol
@@ -102,7 +101,10 @@ int LookupProtoByNumber(const int protonum, char *buf, size_t bufsize,
     name = strtok_r(line, " \t\r\n\v", &tok);
     number = strtok_r(NULL, " \t\r\n\v", &tok);
     if (name && number && protonum == atoi(number)) {
-      strncpy(buf, name, bufsize);
+      if (!memccpy(buf, name, '\0', bufsize)) {
+        strcpy(buf, "");
+        break;
+      }
       found = 1;
     }
   }
@@ -170,8 +172,11 @@ int LookupProtoByName(const char *protoname, char *buf, size_t bufsize,
 
       if (alias) /* alias matched with protoname */
       {
+        if (!memccpy(buf, name, '\0', bufsize)) {
+          strcpy(buf, "");
+          break;
+        }
         result = atoi(number);
-        strncpy(buf, name, bufsize);
         found = 1;
       }
     }

libc/dns/servicestxt.c

@@ -56,12 +56,11 @@ static textwindows noinline char *GetNtServicesTxtPath(char *pathbuf,
  *
  * format of /etc/services is like this:
  *
- *      # comment
+ * # comment
- *      # NAME      PORT/PROTOCOL   ALIASES
+ * # NAME       PORT/PROTOCOL       ALIASES
- *
+ * ftp          21/tcp
- *      ftp		    21/tcp
+ * fsp          21/udp              fspd
- *      fsp		    21/udp		    fspd
+ * ssh          22/tcp
- *      ssh		    22/tcp
  *
  * @param servport is the port number
  * @param servproto is a NULL-terminated string (eg "tcp", "udp")
@@ -102,6 +101,7 @@ int LookupServicesByPort(const int servport, char *servproto,
   line = NULL;
   linesize = 0;
   found = 0;
+  strcpy(buf, "");
 
   while (found == 0 && (getline(&line, &linesize, f)) != -1) {
     if ((comment = strchr(line, '#'))) *comment = '\0';
@@ -110,9 +110,15 @@ int LookupServicesByPort(const int servport, char *servproto,
     proto = strtok_r(NULL, " \t\r\n\v", &tok);
     if (name && port && proto && servport == atoi(port)) {
       if (!servproto[0] || strncasecmp(proto, servproto, servprotolen) == 0) {
-        strncpy(buf, name, bufsize);
+        if (!servproto[0] && !memccpy(servproto, proto, '\0', servprotolen)) {
+          strcpy(servproto, "");
+          break;
+        }
+        if (!memccpy(buf, name, '\0', bufsize)) {
+          strcpy(buf, "");
+          break;
+        }
         found = 1;
-        if (!servproto[0]) strncpy(servproto, proto, servprotolen);
       }
     }
   }
@@ -175,6 +181,7 @@ int LookupServicesByName(const char *servname, char *servproto,
   linesize = 0;
   found = 0;
   result = -1;
+  if (buf && bufsize != 0) strcpy(buf, "");
 
   while (found == 0 && (getline(&line, &linesize, f)) != -1) {
     if ((comment = strchr(line, '#'))) *comment = '\0';
@@ -189,10 +196,16 @@ int LookupServicesByName(const char *servname, char *servproto,
       if (alias) /* alias matched with servname */
       {
         if (!servproto[0] || strncasecmp(proto, servproto, servprotolen) == 0) {
+          if (!servproto[0] && !memccpy(servproto, proto, '\0', servprotolen)) {
+            strcpy(servproto, "");
+            break;
+          }
+          if (buf && bufsize != 0 && !memccpy(buf, name, '\0', bufsize)) {
+            strcpy(buf, "");
+            break;
+          }
           result = atoi(port);
           found = 1;
-          if (!servproto[0]) strncpy(servproto, proto, servprotolen);
-          if (buf && bufsize != 0) strncpy(buf, name, bufsize);
         }
       }
     }

test/libc/dns/prototxt_test.c

@@ -48,10 +48,15 @@ ggp	    3	GGP		    ";
 
 TEST(LookupProtoByNumber, GetNameWhenNumberCorrect) {
   char name[16]; /* sample has only names of length 3-4 */
+  strcpy(name, "");
 
   ASSERT_EQ(-1, /*non-existent number */
             LookupProtoByNumber(24, name, sizeof(name), "protocols"));
 
+  ASSERT_EQ(-1, /* sizeof(name) insufficient, memccpy failure */
+            LookupProtoByNumber(73, name, 1, "protocols"));
+  ASSERT_STREQ(name, ""); /* cleaned up after memccpy failed */
+
   ASSERT_EQ(0, /* works with valid number */
             LookupProtoByNumber(73, name, sizeof(name), "protocols"));
   ASSERT_STREQ(name, "rspf"); /* official name written */
@@ -59,10 +64,15 @@ TEST(LookupProtoByNumber, GetNameWhenNumberCorrect) {
 
 TEST(LookupProtoByName, GetNumberWhenNameOrAlias) {
   char name[16]; /* sample has only names of length 3-4 */
+  strcpy(name, "");
 
   ASSERT_EQ(-1, /* non-existent name or alias */
             LookupProtoByName("tcp", name, sizeof(name), "protocols"));
 
+  ASSERT_EQ(-1, /* sizeof(name) insufficient, memccpy failure */
+            LookupProtoByName("ggp", name, 1, "protocols"));
+  ASSERT_STREQ(name, ""); /* cleaned up after memccpy failed */
+
   ASSERT_EQ(3, /* works with valid name */
             LookupProtoByName("ggp", name, sizeof(name), "protocols"));
   ASSERT_STREQ(name, "ggp");

test/libc/dns/servicestxt_test.c

@@ -53,8 +53,8 @@ TEST(LookupServicesByPort, GetNameWhenPortCorrect) {
   char proto1[] = "tcp";
   char proto2[] = "udp";
   char* localproto;
-
+  strcpy(eitherproto, "");
-  eitherproto[0] = '\0';
+  strcpy(name, "");
 
   localproto = eitherproto;
   ASSERT_EQ(-1, /* non existent port */
@@ -80,6 +80,19 @@ TEST(LookupServicesByPort, GetNameWhenPortCorrect) {
       LookupServicesByPort(22, localproto, 0, name, sizeof(name), "services"));
   ASSERT_STREQ(proto1, "tcp");
 
+  localproto = proto1;
+  ASSERT_EQ(-1, /* sizeof(name) insufficient, memccpy failure */
+            LookupServicesByPort(22, localproto, sizeof(proto1), name, 1,
+                                 "services"));
+  ASSERT_STREQ(proto1, "tcp");
+  ASSERT_STREQ(name, ""); /* cleaned up after memccpy failed */
+
+  localproto = eitherproto;
+  ASSERT_EQ(
+      -1, /* sizeof(proto) insufficient, memccpy failure */
+      LookupServicesByPort(22, localproto, 1, name, sizeof(name), "services"));
+  ASSERT_STREQ(eitherproto, ""); /* cleaned up after memccpy failed */
+
   localproto = proto1;
   ASSERT_EQ(0, LookupServicesByPort(22, localproto, sizeof(proto1), name,
                                     sizeof(name), "services"));
@@ -107,7 +120,8 @@ TEST(LookupServicesByName, GetPortWhenNameOrAlias) {
   char proto1[] = "tcp";
   char proto2[] = "udp";
   char* localproto;
-  eitherproto[0] = '\0';
+  strcpy(eitherproto, "");
+  strcpy(name, "");
 
   localproto = eitherproto;
   ASSERT_EQ(-1, /* non-existent name */
@@ -127,6 +141,19 @@ TEST(LookupServicesByName, GetPortWhenNameOrAlias) {
                                  "services"));
   ASSERT_STREQ(proto2, "udp");
 
+  localproto = proto1;
+  ASSERT_EQ(-1, /* sizeof(name) insufficient, memccpy failure */
+            LookupServicesByName("ssh", localproto, sizeof(proto1), name, 1,
+                                 "services"));
+  ASSERT_STREQ(proto1, "tcp");
+  ASSERT_STREQ(name, ""); /* cleaned up after memccpy failed */
+
+  localproto = eitherproto;
+  ASSERT_EQ(-1, /* sizeof(proto) insufficient, memccpy failure */
+            LookupServicesByName("ssh", localproto, 1, name, sizeof(name),
+                                 "services"));
+  ASSERT_STREQ(eitherproto, ""); /* cleaned up after memccpy failed */
+
   localproto = proto1;
   ASSERT_EQ(22, LookupServicesByName("ssh", localproto, sizeof(proto1), name,
                                      sizeof(name), "services"));
@@ -144,7 +171,6 @@ TEST(LookupServicesByName, GetPortWhenNameOrAlias) {
             LookupServicesByName("ttytst", localproto, sizeof(proto2), NULL, 0,
                                  "services"));
 
-  name[0] = '\0';
   localproto = eitherproto;
   ASSERT_EQ(19, /* pick first matching protocol */
             LookupServicesByName("source", localproto, sizeof(eitherproto),