Support for HTTP redirects.

http.c

@@ -14,6 +14,7 @@
 #include "http.h"
 #include "tcpconnection.h"
 #include "strcasecmp.h"
+#include "seturl.h"
 
 #define buffTypePointer 0x0000      /* For TCPIPReadTCP() */
 #define buffTypeHandle 0x0001
@@ -70,31 +71,52 @@ Boolean BuildHTTPRequest(Session *sess, char *resourceStr) {
     } while (round++ == 0);
     
     sess->httpRequestRange = sess->httpRequest + rangeOffset;
+    
+    UpdateRequestRange(sess, sess->desiredStart, sess->desiredEnd);
+    
     return TRUE;
 }
 
+
 void UpdateRequestRange(Session *sess, unsigned long start, unsigned long end) {
     int count = 
         snprintf(sess->httpRequestRange, 10+1+10+5, "%lu-%lu\r\n\r\n", start, end);
 
+    sess->desiredStart = start;
+    sess->desiredEnd = end;
+
     sess->httpRequestLen = sess->httpRequestRange - sess->httpRequest + count;
 }
 
-#pragma debug -1
 
 enum RequestResult DoHTTPRequest(Session *sess) {
 top:;
     rlrBuff rlrBuff = {0};
     Word tcpError;
-    Boolean wantRedirect = FALSE;
+    Boolean wantRedirect = FALSE, gotRedirect = FALSE;
     enum RequestResult result;
     
+    sess->responseCode = 0;
+
     /* Send out request */
     result = NETWORK_ERROR;
+    unsigned int netErrors = 0;
+    do {
+        if (!sess->tcpLoggedIn || netErrors) {
+            if (StartTCPConnection(sess) != 0)
+                goto errorReturn;
+        }
         tcpError = TCPIPWriteTCP(sess->ipid, sess->httpRequest,
                                  sess->httpRequestLen, TRUE, FALSE);
-    if (tcpError || toolerror())
+        if (tcpError || toolerror()) {
+            if (netErrors == 0) {
+                netErrors++;
+                continue;
+            } else {
                 goto errorReturn;
+            }
+        }
+    } while (0);
     
     /* Get response status line & headers */
     LongWord startTime = GetTick();
@@ -158,7 +180,7 @@ top:;
     response++;
 
 
-    switch(sess->responseCode) {
+    switch((unsigned int)sess->responseCode) {
     /* "Partial content" response, as expected */
     case 206:
         break;
@@ -190,6 +212,12 @@ top:;
     while (response < responseEnd - 2) {
         enum ResponseHeader header = UNKNOWN_HEADER;
         
+        if (wantRedirect) {
+            if (strncasecmp(response, "Location:", 9) == 0) {
+                response += 9;
+                header = LOCATION;
+            }
+        } else {
             if (strncasecmp(response, "Content-Range:", 14) == 0) {
                 response += 14;
                 header = CONTENT_RANGE;
@@ -202,9 +230,7 @@ top:;
             } else if (strncasecmp(response, "Content-Encoding:", 17) == 0) {
                 response += 17;
                 header = CONTENT_ENCODING;
-        } else if (strncasecmp(response, "Location:", 9) == 0) {
+            }
-            response += 9;
-            header = LOCATION;
         }
         
         while ((*response == ' ' || *response == '\t') && response < responseEnd)
@@ -240,7 +266,9 @@ top:;
         case CONTENT_LENGTH:
             errno = 0;
             sess->contentLength = strtoul(response, &endPtr, 10);
-            if (errno || sess->contentLength == 0)
+            if (errno)
+                goto errorReturn;
+            if (sess->contentLength == 0 && !wantRedirect)
                 goto errorReturn;
             response = endPtr;
             break;
@@ -254,7 +282,23 @@ top:;
             }
             break;
         
-        case LOCATION: /*TODO*/ ;
+        case LOCATION:
+            endPtr = response;
+            char c;
+            while ((c = *endPtr)!=0 && c!='\r' && c!='\n' && c!=' ' && c!='\t')
+                endPtr++;
+            if (c == '\0' || c == '\n')
+                goto errorReturn;
+            if (wantRedirect) {
+                *endPtr = '\0';
+                if (SetURL(sess, response, FALSE, TRUE) != SETURL_SUCCESSFUL) {
+                    result = REDIRECT_ERROR;
+                    goto errorReturn;
+                }
+                *endPtr = c;
+                response = endPtr;
+                gotRedirect = TRUE;
+            }
         
         /* Unknown headers: ignored */
         case UNKNOWN_HEADER:
@@ -275,14 +319,35 @@ top:;
         response++;
     }
     
-    /* Wanted redirect, but to Location header found */
+    /* Wanted redirect: Retry with new location if we got it. */
     if (wantRedirect) {
+        if (gotRedirect) {
+            DisposeHandle(rlrBuff.rlrBuffHandle);
+            goto top;
+        } else {
             result = UNSUPPORTED_RESPONSE;
             goto errorReturn;
         }
+    }
     
+    /* See if we got what we wanted */
+    if (sess->expectedLength != 0 && sess->totalLength != sess->expectedLength) {
+        result = DIFFERENT_LENGTH;
+        goto errorReturn;
+    }
+    
+    result = NOT_DESIRED_CONTENT;
+    if (sess->rangeStart != sess->desiredStart)
+        goto errorReturn;
+    if (sess->rangeEnd != sess->desiredEnd)
+        goto errorReturn;
+    if (sess->contentLength != 0 
+        && sess->contentLength != (sess->desiredEnd - sess->desiredStart + 1))
+        goto errorReturn;
+
+    result = REQUEST_SUCCESSFUL;
     DisposeHandle(rlrBuff.rlrBuffHandle);
-    return REQUEST_SUCCESSFUL;
+    return result;
     
 errorReturn:
     if (rlrBuff.rlrBuffHandle != NULL) {

http.h

@@ -12,6 +12,9 @@ enum RequestResult {
     EXCESSIVE_REDIRECTS,
     UNSUPPORTED_RESPONSE,
     UNSUPPORTED_HEADER_VALUE,
+    REDIRECT_ERROR,
+    NOT_DESIRED_CONTENT,
+    DIFFERENT_LENGTH, /* Might be considered successful later */
 };
 
 Boolean BuildHTTPRequest(Session *sess, char *resourceStr);

main.c

@@ -17,7 +17,7 @@ redirects to:
 http://ia800505.us.archive.org/16/items/a2gs_System_1.0_1986_Apple_FW/System_1.0_1986_Apple_FW.2mg
 */
 
-char *defaultURL = "http://ia800505.us.archive.org/16/items/a2gs_System_1.0_1986_Apple_FW/System_1.0_1986_Apple_FW.2mg";
+char *defaultURL = "http://archive.org/download/a2gs_System_1.0_1986_Apple_FW/System_1.0_1986_Apple_FW.2mg";
 
 
 int main(int argc, char **argv) {
@@ -60,14 +60,9 @@ int main(int argc, char **argv) {
     printf("=========\n");
     printf("\n", i);
 
-    int err;
-    if ((err = StartTCPConnection(&sess)) != 0) {
-        printf("StartTCPConnection error %i\n", err);
-        goto exit;
-    }
-    
     enum RequestResult requestResult = DoHTTPRequest(&sess);
     printf("RequestResult %i\n", requestResult);
+    printf("Response code %lu\n", sess.responseCode);
 
     if (requestResult == REQUEST_SUCCESSFUL) {
         printf("rangeStart    = %lu\n", sess.rangeStart);

session.h

@@ -24,7 +24,7 @@ typedef struct Session {
     LongWord httpRequestLen;
     
     /* HTTP response code */
-    unsigned long responseCode;
+    LongWord responseCode;
 
     /* IP address and TCP port of host */
     LongWord ipAddr;
@@ -42,6 +42,11 @@ typedef struct Session {
     LongWord rangeStart, rangeEnd, totalLength;
     /* Value reported by server in Content-Length header */
     LongWord contentLength;
+    
+    /* Desired start/end of range for next request */
+    LongWord desiredStart, desiredEnd;
+    /* Expected length of disk image */
+    LongWord expectedLength;
 } Session;
 
 #endif

tcpconnection.c

@@ -1,7 +1,7 @@
 #pragma noroot
 
-#define aspNetworkErr 1
+#define NETWORK_ERR 1
-#define aspNoRespErr 2
+#define NO_RESP_ERR 2
 
 #include <tcpip.h>
 #include <stdlib.h>
@@ -26,15 +26,15 @@ Word StartTCPConnection(Session *sess) {
     sess->ipid = 
         TCPIPLogin(userid(), sess->ipAddr, sess->port, 0, 0x40);
     if (toolerror())
-        return aspNetworkErr;
+        return NETWORK_ERR;
     
     tcperr = TCPIPOpenTCP(sess->ipid);
     if (toolerror()) {
         TCPIPLogout(sess->ipid);
-        return aspNetworkErr;
+        return NETWORK_ERR;
     } else if (tcperr != tcperrOK) {
         TCPIPLogout(sess->ipid);
-        return aspNoRespErr;
+        return NO_RESP_ERR;
     }
     
     initialTime = GetTick();
@@ -45,7 +45,7 @@ Word StartTCPConnection(Session *sess) {
     if (mySRBuff.srState != TCPSESTABLISHED) {
         TCPIPAbortTCP(sess->ipid);
         TCPIPLogout(sess->ipid);
-        return aspNoRespErr;
+        return NO_RESP_ERR;
     }
     
     sess->tcpLoggedIn = TRUE;