Add code to parse status line and headers of an HTTP response to our request.

http.c

@@ -3,9 +3,34 @@
 
 #include <stdlib.h>
 #include <stdio.h>
+#include <string.h>
 #include <types.h>
+#include <tcpip.h>
+#include <misctool.h>
+#include <memory.h>
+#include <orca.h>
+#include <errno.h>
 #include "session.h"
 #include "http.h"
+#include "tcpconnection.h"
+#include "strcasecmp.h"
+
+#define buffTypePointer 0x0000      /* For TCPIPReadTCP() */
+#define buffTypeHandle 0x0001
+#define buffTypeNewHandle 0x0002
+
+#define HTTP_RESPONSE_TIMEOUT 15 /* seconds to wait for response headers */
+
+#define MAX_REDIRECTS 5
+
+enum ResponseHeader {
+    UNKNOWN_HEADER = 0,
+    CONTENT_RANGE,
+    CONTENT_LENGTH, 
+    TRANSFER_ENCODING,
+    CONTENT_ENCODING,
+    LOCATION,
+};
 
 Boolean BuildHTTPRequest(Session *sess, char *resourceStr) {
     int sizeNeeded = 0;
@@ -49,5 +74,222 @@ Boolean BuildHTTPRequest(Session *sess, char *resourceStr) {
 }
 
 void UpdateRequestRange(Session *sess, unsigned long start, unsigned long end) {
-    snprintf(sess->httpRequestRange, 10+1+10+5, "%lu-%lu\r\n\r\n", start, end);
+    int count = 
+        snprintf(sess->httpRequestRange, 10+1+10+5, "%lu-%lu\r\n\r\n", start, 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;
+    enum RequestResult result;
+
+    /* Send out request */
+    result = NETWORK_ERROR;
+    tcpError = TCPIPWriteTCP(sess->ipid, sess->httpRequest,
+                             sess->httpRequestLen, TRUE, FALSE);
+    if (tcpError || toolerror())
+        goto errorReturn;
+    
+    /* Get response status line & headers */
+    LongWord startTime = GetTick();
+    do {
+        TCPIPPoll();
+        tcpError = TCPIPReadLineTCP(sess->ipid,
+                (void*)((LongWord)"\p\r\n\r\n" | 0x80000000),
+                buffTypeNewHandle, (Ref)NULL,
+                0xFFFFFF, &rlrBuff);
+        if (tcpError || toolerror())
+            goto errorReturn;
+    } while (rlrBuff.rlrBuffCount == 0 
+             && GetTick() - startTime < HTTP_RESPONSE_TIMEOUT * 60);
+
+    result = NO_RESPONSE;
+    if (!rlrBuff.rlrIsDataFlag)
+        goto errorReturn;
+
+    result = INVALID_RESPONSE;
+    /* Response must be at least long enough for a status line & final CRLF */
+    if (rlrBuff.rlrBuffCount < 8+1+3+1+2+2)
+        goto errorReturn;
+    
+    HLock(rlrBuff.rlrBuffHandle);
+    
+    char *response = *rlrBuff.rlrBuffHandle;
+    char *responseEnd = response + rlrBuff.rlrBuffCount;
+    /* Make response a C-string. Specifically, it will end "CR LF NUL NUL". */
+    response[rlrBuff.rlrBuffCount - 2] = '\0';
+    response[rlrBuff.rlrBuffCount - 1] = '\0';
+    
+    /* Parse status line of HTTP response */
+    char *endPtr;
+    
+    if (strncmp(response, "HTTP/1.", 7) != 0)
+        goto errorReturn;
+    response += 7;
+    if (!(*response >= '1' && *response <= '9'))
+        goto errorReturn;
+    response += 1;
+    if (*response != ' ')
+        goto errorReturn;
+    response += 1;
+    
+    errno = 0;
+    sess->responseCode = strtoul(response, &endPtr, 10);
+    if (errno || sess->responseCode > 999 || endPtr != response + 3)
+        goto errorReturn;
+    response += 3;
+    
+    if (*response != ' ')
+        goto errorReturn;
+    response++;
+    
+    while (*response != '\r' && response < responseEnd)
+        response++;
+    response++;
+    
+    if (*response != '\n' && response < responseEnd)
+        goto errorReturn;
+    response++;
+
+
+    switch(sess->responseCode) {
+    /* "Partial content" response, as expected */
+    case 206:
+        break;
+    
+    /* Redirect responses */
+    case 300: case 301: case 302: case 307: case 308:
+        if (sess->redirectCount < MAX_REDIRECTS) {
+            sess->redirectCount++;
+            wantRedirect = TRUE;
+            break;
+        } else {
+            result = EXCESSIVE_REDIRECTS;
+            goto errorReturn;
+        }
+              
+    default:
+        result = UNSUPPORTED_RESPONSE;
+        goto errorReturn;
+    }
+
+    /* Parse response headers */
+    sess->rangeStart = 0;
+    sess->rangeEnd = 0;
+    sess->totalLength = 0;
+    sess->contentLength = 0;
+    
+    result = UNSUPPORTED_HEADER_VALUE;
+
+    while (response < responseEnd - 2) {
+        enum ResponseHeader header = UNKNOWN_HEADER;
+        
+        if (strncasecmp(response, "Content-Range:", 14) == 0) {
+            response += 14;
+            header = CONTENT_RANGE;
+        } else if (strncasecmp(response, "Content-Length:", 15) == 0) {
+            response += 15;
+            header = CONTENT_LENGTH;
+        } else if (strncasecmp(response, "Transfer-Encoding:", 18) == 0) {
+            response += 18;
+            header = TRANSFER_ENCODING;
+        } 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)
+            response++;
+        
+        switch (header) {
+        case CONTENT_RANGE:
+            if (strncasecmp(response, "bytes ", 6) != 0)
+                goto errorReturn;
+            response += 6;
+        
+            errno = 0;
+            sess->rangeStart = strtoul(response, &response, 10);
+            if (errno)
+                goto errorReturn;
+            if (*response != '-')
+                goto errorReturn;
+            response++;
+            
+            sess->rangeEnd = strtoul(response, &response, 10);
+            if (errno || sess->rangeEnd == 0)
+                goto errorReturn;
+            if (*response != '/')
+                goto errorReturn;
+            response++;
+            
+            /* require numeric total length, not indeterminate '*' */
+            sess->totalLength = strtoul(response, &response, 10);
+            if (errno || sess->totalLength == 0)
+                goto errorReturn;
+            break;
+        
+        case CONTENT_LENGTH:
+            errno = 0;
+            sess->contentLength = strtoul(response, &endPtr, 10);
+            if (errno || sess->contentLength == 0)
+                goto errorReturn;
+            response = endPtr;
+            break;
+        
+        case CONTENT_ENCODING:
+        case TRANSFER_ENCODING:
+            if (strcasecmp(response, "identity") == 0) {
+                response += 8;
+            } else {
+                goto errorReturn;
+            }
+            break;
+        
+        case LOCATION: /*TODO*/ ;
+        
+        /* Unknown headers: ignored */
+        case UNKNOWN_HEADER:
+        default:
+            while (*response != '\r' && response < responseEnd)
+                response++;
+            break;
+        }
+        
+        while ((*response == ' ' || *response == '\t') && response < responseEnd)
+            response++;
+        
+        if (*response != '\r')
+            goto errorReturn;
+        response++;
+        if (*response != '\n')
+            goto errorReturn;
+        response++;
+    }
+    
+    /* Wanted redirect, but to Location header found */
+    if (wantRedirect) {
+        result = UNSUPPORTED_RESPONSE;
+        goto errorReturn;
+    }
+    
+    DisposeHandle(rlrBuff.rlrBuffHandle);
+    return REQUEST_SUCCESSFUL;
+    
+errorReturn:
+    if (rlrBuff.rlrBuffHandle != NULL) {
+        DisposeHandle(rlrBuff.rlrBuffHandle);
+    }
+
+    /* Error condition on this TCP connection means it can't be reused. */
+    EndTCPConnection(sess);
+    return result;
 }

http.h

@@ -4,7 +4,18 @@
 #include <types.h>
 #include "session.h"
 
+enum RequestResult {
+    REQUEST_SUCCESSFUL = 0,
+    NETWORK_ERROR,
+    NO_RESPONSE,
+    INVALID_RESPONSE,
+    EXCESSIVE_REDIRECTS,
+    UNSUPPORTED_RESPONSE,
+    UNSUPPORTED_HEADER_VALUE,
+};
+
 Boolean BuildHTTPRequest(Session *sess, char *resourceStr);
 void UpdateRequestRange(Session *sess, unsigned long start, unsigned long end);
+enum RequestResult DoHTTPRequest(Session *sess);
 
 #endif

main.c

@@ -11,18 +11,12 @@
 #include "seturl.h"
 #include "hostname.h"
 
-#define buffTypePointer 0x0000      /* For TCPIPReadTCP() */
-#define buffTypeHandle 0x0001
-#define buffTypeNewHandle 0x0002
-
 /*
 http://archive.org/download/a2gs_System_1.0_1986_Apple_FW/System_1.0_1986_Apple_FW.2mg
 redirects to:
 http://ia800505.us.archive.org/16/items/a2gs_System_1.0_1986_Apple_FW/System_1.0_1986_Apple_FW.2mg
 */
 
-static char delimitStr[] = "\p\r\n\r\n";
-
 char *defaultURL = "http://ia800505.us.archive.org/16/items/a2gs_System_1.0_1986_Apple_FW/System_1.0_1986_Apple_FW.2mg";
 
 
@@ -72,32 +66,16 @@ int main(int argc, char **argv) {
         goto exit;
     }
     
-    TCPIPWriteTCP(sess.ipid, sess.httpRequest, strlen(sess.httpRequest), TRUE, FALSE);
+    enum RequestResult requestResult = DoHTTPRequest(&sess);
+    printf("RequestResult %i\n", requestResult);
 
-    rlrBuff rlrBuff = {0};
+    if (requestResult == REQUEST_SUCCESSFUL) {
-    Word tcpError;
+        printf("rangeStart    = %lu\n", sess.rangeStart);
-    do {
+        printf("rangeEnd      = %lu\n", sess.rangeEnd);
-        TCPIPPoll();
+        printf("totalLength   = %lu\n", sess.totalLength);
-        tcpError = TCPIPReadLineTCP(sess.ipid,
+        printf("contentLength = %lu\n", sess.contentLength);
-                (void*)((LongWord)delimitStr | 0x80000000),
-                buffTypeNewHandle, (Ref)NULL,
-                0xFFFFFF, &rlrBuff);
-        if (tcpError || toolerror()) {
-            printf("tcpError = %u, toolerror = %u\n", tcpError, toolerror());
-            break;
-        }
-    } while (rlrBuff.rlrBuffCount == 0);
-
-    printf("Response:\n");
-    printf("=========\n");
-    for (int i = 0; i < rlrBuff.rlrBuffCount; i++) {
-        char ch = ((char*)*(rlrBuff.rlrBuffHandle))[i];
-        if (ch != '\r')
-            putchar(ch);
     }
-    printf("=========\n");
+
-    printf("Response size = %lu\n", rlrBuff.rlrBuffCount);
-    
     EndTCPConnection(&sess);
 
 exit:

session.h

@@ -20,6 +20,11 @@ typedef struct Session {
     char *httpRequest;
     /* Pointer to the range part within httpRequest */
     char *httpRequestRange;
+    /* Length of HTTP request */
+    LongWord httpRequestLen;
+    
+    /* HTTP response code */
+    unsigned long responseCode;
 
     /* IP address and TCP port of host */
     LongWord ipAddr;
@@ -29,6 +34,14 @@ typedef struct Session {
     char hostName[257];
     /* Time (GetTick) of last DNS lookup */
     LongWord dnsTime;
+    
+    /* Number of redirects followed */
+    Word redirectCount;
+    
+    /* Values reported by server in Content-Range header */
+    LongWord rangeStart, rangeEnd, totalLength;
+    /* Value reported by server in Content-Length header */
+    LongWord contentLength;
 } Session;
 
 #endif

seturl.c

@@ -21,7 +21,7 @@ SetURL(Session *sess, char *url, Boolean permissive, Boolean partialOK) {
     }
     
     for(unsigned int i = 0; url[i] != '\0'; i++) {
-        if (url[i] <= ' ' && url[i] >= 0) {
+        if ((unsigned char)url[i] <= ' ') {
             return INVALID_CHARACTER_IN_URL;
         }
     }

urlparser.c

@@ -25,8 +25,8 @@ URLParts ParseURL(char *url) {
     /* Detect relative URL (absolute-path reference only) */
     if (url[0] == '/') {
         if (url[1] != '/') {
-            url++;
+            urlParts.path = url + 1;
-            goto pathPart;
+            return urlParts;
         } else {
             urlParts.errorFound = 1;
             return urlParts;
@@ -90,7 +90,6 @@ URLParts ParseURL(char *url) {
         urlParts.port = sep + 1;
     }
 
-pathPart:
     return urlParts;
 }