I'm lost on server.c. I passed the first check. When trying to run my server after completing the program, I get an internal server error. I ran valgrind and fixed multiple memory issues. I thought that might help, but I still get the error.
I tried to read other QA with similar problems. I'm thinking it is in my parse function (possibly null terminator?). strtok and strcpy are supposed to included null characters, so I didn't think I needed to add anything (and if I do I'm not sure how to add it to the end of the string when I don't know its length). Maybe I'm not on the right track with this but here is my code:
Load:
bool load(FILE* file, BYTE** content, size_t* length)
{
//setup byte counter starting at one since one byte allocated to start buffer
int counter = 1;
//setup buffer in memory
BYTE* buffer = malloc(sizeof(BYTE)); //was a char* but per another QA images can cause problems when allocating with char
//return false if buffer not loaded
if(buffer == NULL)
{
return false;
}
//reads through file and gets chars one at a time until the end of the file
for (int c = fgetc(file); c != EOF; c = fgetc(file))
{
buffer[counter - 1] = c; //adds the char to the buffer starting at 0
counter++; //increase the byte counter
buffer = realloc(buffer, counter + 1); //adds new memory to buffer by adding a byte to the current number of bytes
}
*content = buffer; //updates content pointer to buffer sector of memory?
*length = counter;
free(buffer);
return false;
}
Lookup:
const char* lookup(const char* path)
{
// TODO - function is inputed the path, need to scan it for file type and return supported extension
//declare period so can search for in path
const char period = '.';
//strchr sets pointer at the location of the period, effectively truncating string to start at file extension
char* pathext = strchr(path,period);
//declare the 8 extensions and corresponding MIME types
char* extension[8] = {".css",".html",".gif",".ico",".jpg",".js",".php",".png"};
char* mimetype[8] = {"text/css","text/html","image/x-icon","image/gif","image/jpeg","text/javascript","text/x-php","image/png"};
//function to check if the path extension is equal to any of the given extension and if so return corresponding MIME
for(int i = 0; i < 8; i++)
{
if(strcasecmp(pathext,extension[i])==0)
{
return mimetype[i];
}
}
//lookup returns NULL if the path does not end in one of the 8 extensions
return NULL;
}
Parse:
bool parse(const char* line, char* abs_path, char* query)
{
//create copy of line in memory so it can be manipulated
char* templine = malloc(sizeof(char) * (LimitRequestLine + 1));
strcpy(templine,line);
//use strtok function to split line into words http://stackoverflow.com/questions/26330219/split-line-into-array-of-words-c
char* method = strtok(templine, " ");
char* absolute_path = strtok(NULL, " ");
char* httpver = strtok(NULL, "\r\n");
//checks format of line, aka that method absolute_path and httpver exist
//do I also need to ensure line ends after hpp or does \r\n take care of that?
if(method == NULL || absolute_path == NULL || httpver == NULL)
{
error(400);
free(templine);
return false;
}
//checks that path starts with /
else if(absolute_path[0] != '/')
{
error(501);
free(templine);
return false;
}
//checks that path does not contain quotes by moving pointer to it if it exists - null if doesn't exist
else if(strchr(absolute_path,'\"') != NULL)
{
error(400);
free(templine);
return false;
}
//checks that method equals GET
else if(strcasecmp("GET", method) != 0)
{
error(405);
free(templine);
return false;
}
else if(strcasecmp(httpver,"HTTP/1.1") != 0)
{
error(505);
free(templine);
return false;
}
else
{
//code to transfer absolute_path to abs_path - strcpy should transfer null pointer?
strcpy(abs_path,absolute_path);
//copy query by allocating memory and setting pointer to character after the question mark
//if path doesn't contain a question mark, query blank
if(strchr(absolute_path, '?') == NULL)
{
query = "";
}
//if path contains a question mark but terminates after question mark, query blank
else if(strcmp(strchr(absolute_path, '?') + 1, "\0") == 0)
{
query = "";
}
//in all other cases, use strchr to start "query" at the point after the question mark
else
{
query = strchr(absolute_path, '?') + 1;
}
printf("Query: %s\n", query); //check on query
free(templine);
return true;
}
}
Index
char* indexes(const char* path)
{
// TODO
//copying path into new sect of memory so it can be manipulated. left room for php or html file to be added
char* phppath = malloc(strlen(path)*sizeof(BYTE) + 9 + 1);
phppath = strcpy(phppath,path);
char* htmlpath = malloc(strlen(path)*sizeof(BYTE) + 10 + 1);
htmlpath = strcpy(htmlpath,path);
//setup string to be found in directory
char* phpfile = "index.php";
char* htmlfile = "index.html";
//combine path with index file to check in directory
phppath = strcat(phppath, phpfile);
htmlpath = strcat(htmlpath, htmlfile);
//check if php or html exist (in that order) and returns respective path or null if doesn't exist
//access function F_OK checks that file exists in directory and returns 0 if true
if (access(phppath, F_OK) == 0)
{
free(htmlpath);
return phppath;
}
else if (access(htmlpath, F_OK) == 0)
{
free(phppath);
return htmlpath;
}
else
{
free(htmlpath);
free(phppath);
return NULL;
}
}
Any help is appreciated. I think I get more confused the more I look back at the code.
To give further information. When I run GDB, I get:
(gdb) n
Abolute path is '/cat.jpg'Query:
798 printf("The query is ?%s\n", query); //check on query
(gdb) n
799 free(templine);
(gdb) n
802 }
(gdb) n
main (argc=2, argv=0x7fffffffde88) at server.c:189
189 char* p = urldecode(abs_path);
(gdb) n
190 if (p == NULL)
(gdb) n
197 path = malloc(strlen(root) + strlen(p) + 1);
(gdb) n
198 if (path == NULL)
(gdb) n
203 strcpy(path, root);
(gdb) n
204 strcat(path, p);
(gdb) n
205 free(p);
(gdb) n
208 if (access(path, F_OK) == -1)
(gdb) n
216 if (stat(path, &sb) == 0 && S_ISDIR(sb.st_mode))
(gdb) n
245 const char* type = lookup(path);
(gdb) n
246 if (type == NULL)
(gdb) n
253 if (strcasecmp("text/x-php", type) == 0)
(gdb) n
261 transfer(path, type);
(gdb) n
HTTP/1.1 500 Internal Server Error
263 }
(gdb)
I'm not sure exactly what to make of this. I started with a breakpoint at my parse function and it appears to report (printf) the "absolute_path correctly." Since the crash is part of main function that deals with abs_path, I think the problem is there but can't pinpoint it.
