1 files changed, 183 insertions, 0 deletions
diff --git a/http.c b/http.c
new file mode 100644
index 0000000..69f3499
--- /dev/null
+++ b/http.c
@@ -0,0 +1,183 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <stdbool.h>
+#include <string.h>
+#include <ctype.h>
+#include <sys/socket.h>
+#include "http.h"
+#include "memory.h"
+#include "util.h"
+
+
+static void free_list(char **list,int nitems){
+	for(int i=0;i<nitems;i++){
+		free(list[i]);
+	}
+	free(list);
+}
+
+// -2: error; -1: socket closed; >=0: length of string
+static int sock_get_line(char **dst,int sock){
+	int linesz=128,linelen=0;
+	char *line=malloc(linesz,char);
+	bool haveCR=false,alsoCR=false;
+	while(true){
+		char c;
+		ssize_t ret=recv(sock,&c,1,0);
+		if(ret<=0){
+			free(line);
+			*dst=NULL;
+			return ret-1;
+		}
+		if(c=='\r'){
+			haveCR=true;
+			continue;
+		} else if(c=='\n'){
+			break;
+		} else if(haveCR){
+			haveCR=false;
+			alsoCR=true;
+		}
+		if(linelen+1+alsoCR==linesz){
+			linesz*=2;
+			if(linesz==0){
+				exit(255); // Integer overflow!
+			}
+			line=realloc(line,linesz,char);
+		}
+		if(alsoCR){
+			line[linelen++]='\r';
+			alsoCR=false;
+		}
+		line[linelen++]=c;
+	}
+	line[linelen]='\0';
+	*dst=line;
+	return linelen;
+}
+
+// Returns number of lines, or -1 if error
+static int get_header_lines(char ***dst,int sock){
+	int arrsz=16,arrlen=0;
+	char **arr=malloc(arrsz,char*);
+	while(true){
+		char *line;
+		int linelen=sock_get_line(&line,sock);
+		if(linelen<0){
+			free_list(arr,arrlen);
+			*dst=NULL;
+			return -1;
+		}
+		if(linelen==0){
+			break;
+		}
+		if(arrlen+1==arrsz){
+			arrsz*=2;
+			if(arrsz==0){
+				exit(255); // Integer overflow!
+			}
+			arr=realloc(arr,arrsz,char*);
+		}
+		arr[arrlen++]=line;
+	}
+	arr[arrlen]=NULL;
+	*dst=arr;
+	return arrlen;
+}
+
+static Headers* alloc_headers(void){
+	Headers *headers=malloc(1,Headers);
+	headers->method=NULL;
+	headers->url=NULL;
+	headers->version=NULL;
+	headers->nheaders=0;
+	headers->headers=NULL;
+	return headers;
+}
+
+void free_headers(Headers *headers){
+	if(headers==NULL){
+		return;
+	}
+
+	if(headers->method)free(headers->method);
+	if(headers->url)free(headers->url);
+	if(headers->version)free(headers->version);
+
+	if(headers->headers){
+		for(int i=0;i<headers->nheaders;i++){
+			free(headers->headers[i][0]);
+			free(headers->headers[i][1]);
+		}
+		free(headers->headers);
+	}
+
+	free(headers);
+}
+
+Headers* http_get_headers(int sock){
+	char **lines;
+	int nlines=get_header_lines(&lines,sock);
+	if(nlines<0){
+		return NULL;
+	}
+	if(nlines==0){
+		free_list(lines,nlines);
+		return NULL;
+	}
+
+	char *spacep=strchr(lines[0],' ');
+	char *space2p=strrchr(lines[0],' ');
+	if(spacep==NULL||space2p==NULL){
+		free_list(lines,nlines);
+		return NULL;
+	}
+	char *urlstart=spacep+1;
+	while(isspace(*urlstart)){
+		urlstart++;
+	}
+	if(urlstart>space2p){ // No url?
+		free_list(lines,nlines);
+		return NULL;
+	}
+
+	Headers *headers=alloc_headers();
+
+	headers->method=copy_buf(lines[0],spacep-lines[0]);
+	str_toupper(headers->method);
+	headers->url=copy_buf(urlstart,space2p-urlstart);
+	headers->version=copy_str(space2p);
+	str_toupper(headers->version);
+
+	int hsz=16;
+	headers->nheaders=0;
+	headers->headers=malloc(hsz,Header);
+
+	for(int i=1;i<nlines;i++){
+		char *colonp=strchr(lines[i],':');
+		if(colonp==NULL){
+			free_list(lines,nlines);
+			free_headers(headers);
+			return NULL;
+		}
+		char *valuep=colonp+1;
+		while(isspace(*valuep)){
+			valuep++;
+		}
+
+		if(headers->nheaders+1==hsz){
+			hsz*=2;
+			// Don't need to check overflow, because nlines would have
+			// overflowed already
+			headers->headers=realloc(headers->headers,hsz,Header);
+		}
+		headers->headers[headers->nheaders][0]=copy_buf(lines[i],colonp-lines[i]);
+		headers->headers[headers->nheaders][1]=copy_str(valuep);
+		headers->nheaders++;
+	}
+	headers->headers[headers->nheaders][0]=NULL;
+	headers->headers[headers->nheaders][1]=NULL;
+
+	free_list(lines,nlines);
+	return headers;
+}