add rudimentary http-get tool similar to fetch

Makefile

@@ -1,4 +1,4 @@
-APPS=init hello sh ls terminal uname compositor drawlines background session kdebug cat yutani-test sysinfo hostname yutani-query env mount date echo nyancat kill ps pstree bim terminal-vga cursor-off font-server migrate free uptime
+APPS=init hello sh ls terminal uname compositor drawlines background session kdebug cat yutani-test sysinfo hostname yutani-query env mount date echo nyancat kill ps pstree bim terminal-vga cursor-off font-server migrate free uptime http-get
 
 ifeq ($(TOOLCHAIN),)
   ifeq ($(shell util/check.sh),y)

apps/http-get.c

@@ -0,0 +1,232 @@
+/* vim: ts=4 sw=4 noexpandtab
+ *
+ * Small HTTP fetch tool. Not meant to be complete, this is
+ * written for demo purposes only.
+ */
+#include <stdio.h>
+#include <unistd.h>
+
+#include "../lib/list.c"
+#include "../lib/hashmap.c"
+
+#define SIZE 512
+
+struct uri {
+	char domain[SIZE];
+	char path[SIZE];
+};
+
+void parse_url(char * d, struct uri * r) {
+	if (strstr(d, "http://") == d) {
+
+		d += strlen("http://");
+
+		char * s = strstr(d, "/");
+		if (!s) {
+			strcpy(r->domain, d);
+			strcpy(r->path, "");
+		} else {
+			*s = 0;
+			s++;
+			strcpy(r->domain, d);
+			strcpy(r->path, s);
+		}
+	} else {
+		fprintf(stderr, "sorry, can't parse %s\n", d);
+		exit(1);
+	}
+}
+
+static char read_buf[1024];
+static size_t available = 0;
+static size_t offset = 0;
+static size_t read_from = 0;
+static char * read_line(FILE * f, char * out, ssize_t len) {
+	while (len > 0) {
+		if (available == 0) {
+			if (offset == 1024) {
+				offset = 0;
+			}
+			size_t r = read(fileno(f), &read_buf[offset], 1024 - offset);
+			read_from = offset;
+			available = r;
+			offset += available;
+		}
+
+#if 0
+		fprintf(stderr, "Available: %d\n", available);
+		fprintf(stderr, "Remaining length: %d\n", len);
+		fprintf(stderr, "Read from: %d\n", read_from);
+		fprintf(stderr, "Offset: %d\n", offset);
+#endif
+
+		if (available == 0) {
+			return out;
+		}
+
+		while (read_from < offset && len > 0) {
+			*out = read_buf[read_from];
+			len--;
+			read_from++;
+			available--;
+			if (*out == '\n') {
+				return out;
+			}
+			out++;
+		}
+	}
+
+	return out;
+}
+static size_t read_bytes(FILE * f, char * out, ssize_t len) {
+	size_t r_out = 0;
+	while (len > 0) {
+		if (available == 0) {
+			if (offset == 1024) {
+				offset = 0;
+			}
+			size_t r = read(fileno(f), &read_buf[offset], 1024 - offset);
+			read_from = offset;
+			available = r;
+			offset += available;
+		}
+
+		if (available == 0) {
+			return r_out;
+		}
+
+		while (read_from < offset && len > 0) {
+			*out = read_buf[read_from];
+			len--;
+			read_from++;
+			available--;
+			out++;
+			r_out += 1;
+		}
+	}
+
+	return r_out;
+}
+
+
+void read_http_line(char * buf, FILE * f) {
+	memset(buf, 0x00, 256);
+
+	read_line(f, buf, 255);
+	char * _r = strchr(buf, '\r');
+	if (_r) {
+		*_r = '\0';
+	}
+	if (!_r) {
+		_r = strchr(buf, '\n'); /* that's not right, but, whatever */
+		if (_r) {
+			*_r = '\0';
+		}
+	}
+}
+
+void bad_response(void) {
+	fprintf(stderr, "Bad response.\n");
+	exit(1);
+}
+
+int main(int argc, char * argv[]) {
+
+	if (argc < 2) {
+		fprintf(stderr, "%s: expected an argument\n", argv[0]);
+		return 1;
+	}
+
+	struct uri uri;
+	parse_url(argv[1], &uri);
+
+	char file[100];
+	sprintf(file, "/dev/net/%s", uri.domain);
+
+	FILE * f = fopen(file,"r+");
+
+	if (!f) {
+		fprintf(stderr, "%s: connection to %s failed\n", argv[0], uri.domain);
+		return 1;
+	}
+
+	fprintf(f,
+		"GET /%s HTTP/1.0\r\n"
+		"User-Agent: curl/7.35.0\r\n"
+		"Host: %s\r\n"
+		"Accept: */*\r\n"
+		"\r\n", uri.path, uri.domain);
+
+	hashmap_t * headers = hashmap_create(10);
+
+	/* Parse response */
+	{
+		char buf[256];
+		read_http_line(buf, f);
+		fprintf(stderr, "[%s]\n", buf);
+
+		char * elements[3];
+
+		elements[0] = buf;
+		elements[1] = strchr(elements[0], ' ');
+		if (!elements[1]) bad_response();
+		*elements[1] = '\0';
+		elements[1]++;
+
+		elements[2] = strchr(elements[1], ' ');
+		if (!elements[2]) bad_response();
+		*elements[2] = '\0';
+		elements[2]++;
+
+		if (strcmp(elements[1], "200")) {
+			fprintf(stderr, "Bad response code: %s\n", elements[1]);
+			return 1;
+		}
+	}
+
+	/* Parse headers */
+	while (1) {
+		char buf[256];
+		read_http_line(buf, f);
+
+		if (!*buf) {
+			fprintf(stderr, "(done with headers)\n");
+			break;
+		}
+
+		/* Split */
+		char * name = buf;
+		char * value = strstr(buf, ": ");
+		if (!value) bad_response();
+		*value = '\0';
+		value += 2;
+
+		hashmap_set(headers, name, strdup(value));
+	}
+
+	fprintf(stderr, "Dumping headers.\n");
+	list_t * hash_keys = hashmap_keys(headers);
+	foreach(_key, hash_keys) {
+		char * key = (char *)_key->value;
+		fprintf(stderr, "[%s] = %s\n", key, hashmap_get(headers, key));
+	}
+	list_free(hash_keys);
+	free(hash_keys);
+
+	/* determine how many bytes we should read now */
+	if (!hashmap_has(headers, "Content-Length")) {
+		fprintf(stderr, "Don't know how much to read.\n");
+		return 1;
+	}
+
+	int bytes_to_read = atoi(hashmap_get(headers, "Content-Length"));
+
+	while (bytes_to_read > 0) {
+		char buf[1024];
+		size_t r = read_bytes(f, buf, bytes_to_read < 1024 ? bytes_to_read : 1024);
+		fwrite(buf, 1, r, stdout);
+		bytes_to_read -= r;
+	}
+
+	return 0;
+}