finally put this under version control

mvwtc.c

@@ -0,0 +1,221 @@
+/* full of jank */
+#include <string.h>
+#include <skalibs/env.h>
+#include <skalibs/allreadwrite.h>
+#include <skalibs/unix-transactional.h>
+#include <skalibs/stralloc.h>
+#include <skalibs/bytestr.h>
+#include <skalibs/buffer.h>
+#include <skalibs/skamisc.h>
+#include <skalibs/strerr.h>
+#include <skalibs/djbunix.h>
+#include <skalibs/exec.h>
+
+#include "pdjson.h"
+
+#define MAX(x, y) ((x) > (y) ? (x) : (y))
+#define MIN(x, y) ((x) < (y) ? (x) : (y))
+
+#define USAGE "mvwtc id"
+#define HTTPOK "HTTP/1.1 200 OK"
+
+void
+url_hpn(stralloc *url, stralloc *host, stralloc *path, stralloc *name)
+{
+	char *afterscheme;
+	size_t urli, eohost, lastslash;
+
+	urli = byte_chr(url->s, url->len, '/');
+	urli += 2;
+
+	afterscheme = url->s + urli;
+	eohost = byte_chr(url->s + urli, url->len - urli, '/');
+	stralloc_catb(host, url->s + urli, eohost);
+	stralloc_0(host);
+
+	stralloc_cats(path, url->s + urli + eohost);
+	stralloc_0(host);
+
+	lastslash = byte_rchr(url->s, url->len, '/');
+	stralloc_cats(name, url->s + lastslash + 1);
+	stralloc_0(host);
+}
+
+/* '\n' → '\0' */
+void
+sa_nltoz(stralloc *sa)
+{
+	size_t idx;
+
+	idx = byte_chr(sa->s, sa->len, '\n');
+	if (idx < sa->len) {
+		sa->s[idx] = '\0';
+		sa->len = idx;
+	}
+}
+
+/* '\0' → '\n' */
+void
+sa_ztonl(stralloc *sa)
+{
+	size_t idx;
+
+	idx = byte_chr(sa->s, sa->len, '\0');
+	if (idx < sa->len) {
+		sa->s[idx] = '\n';
+		sa->len = idx + 1;
+	}
+}
+
+/* img url in sa → url */
+int
+imgpath(stralloc *url, stralloc *sa)
+{
+	json_stream j;
+	enum json_type t;
+	const char *key, *val;
+
+	json_open_buffer(&j, sa->s, sa->len);
+	json_set_streaming(&j, 0);
+
+	t = json_next(&j);
+	if (t != JSON_OBJECT) {
+		json_close(&j);
+		return -1;
+	}
+
+	while ((t = json_next(&j)) != JSON_DONE) {
+		switch (t) {
+		case JSON_STRING:
+			key = json_get_string(&j, NULL);
+			if (!strncmp(key, "post_url", MIN(strlen(key),
+							strlen("post_url")))) {
+				/* i'm not sure why there need to be two of these */
+				t = json_next(&j);
+				t = json_next(&j);
+				val = json_get_string(&j, NULL);
+				url->len = 0;
+				stralloc_cats(url, val);
+				stralloc_0(url);
+				return 0;
+			}
+			break;
+		case JSON_OBJECT_END:
+			goto done;
+			break;
+		}
+	}
+done:
+	return -1;
+}
+
+int
+http_recv(int fd, stralloc *sa)
+{
+	char obuf[BUFFER_INSIZE];
+	buffer outb = BUFFER_INIT(&buffer_read, fd, obuf, BUFFER_INSIZE);
+	if (skagetln(&outb, sa, '\n') < 0)
+		return -1;
+	if (sa->len < sizeof(HTTPOK) || !strncmp(sa->s, HTTPOK, sizeof(HTTPOK)))
+		return -1;
+	sa->len = 0;
+
+	/* skip to the end of the header */
+	for (;;) {
+		if (skagetln(&outb, sa, '\n') < 0)
+			return -1;
+		if (!strncmp(sa->s, "\r\n", 2)) {
+			break;
+		}
+		sa->len = 0;
+	}
+
+	sa->len = 0;
+	skagetln(&outb, sa, '\n');
+	// todo handle fuckery here
+	stralloc_0(sa);
+
+	return 0;
+}
+
+int
+http_send(int fd, char *id)
+{
+	char buf[BUFFER_OUTSIZE];
+
+	buffer b = BUFFER_INIT(&buffer_write, fd, buf, BUFFER_OUTSIZE);
+
+	buffer_putsnoflush(&b, "GET /api/links/");
+	buffer_putsnoflush(&b, id);
+	buffer_putsnoflush(&b, ".json HTTP/1.0\r\n");
+	buffer_putsnoflush(&b, "Host: walltaker.joi.how\r\n");
+	buffer_putsnoflush(&b, "Connection: close\r\n");
+	buffer_putsnoflush(&b, "User-Agent: mvwt\r\n\r\n");
+	buffer_flush(&b);
+
+	return 0;
+}
+
+int
+main(int argc, char *argv[])
+{
+	stralloc resp = STRALLOC_ZERO;
+	stralloc img = STRALLOC_ZERO;
+	stralloc currentimg = STRALLOC_ZERO;
+	stralloc tmp = STRALLOC_ZERO;
+	stralloc imhost = STRALLOC_ZERO;
+	stralloc impath = STRALLOC_ZERO;
+	stralloc imfile = STRALLOC_ZERO;
+	PROG = "mvwtc";
+
+	if (argc != 2)
+		strerr_dieusage(100, USAGE);
+	
+	if (http_send(7, argv[1]) < 0)
+		strerr_diefu(111, "send http request");
+	if (http_recv(6, &resp) < 0) {
+		stralloc_free(&resp);
+		strerr_diefu(111, "recieve http response");
+	}
+	fd_shutdown(7, 1);
+	fd_close(7);
+	fd_shutdown(6, 0);
+	fd_close(6);
+
+	if (imgpath(&img, &resp) < 0) {
+		stralloc_free(&img);
+		stralloc_free(&resp);
+		strerr_dief(111, "json seems mangled");
+	}
+	stralloc_free(&resp);
+
+	if (opengetlnclose("current", &currentimg, '\n') >= 0) {
+		sa_nltoz(&currentimg);
+		if (!strncmp(currentimg.s, img.s,
+					MIN(currentimg.len, img.len))) {
+			/* we don't need to do anything, just exit */
+			stralloc_free(&currentimg);
+			stralloc_free(&img);
+			return 0;
+		}
+	}
+
+	stralloc_copy(&tmp, &img);
+	sa_ztonl(&tmp);
+	if (!openwritenclose_suffix6("current", tmp.s, tmp.len, NULL, 0, "~")) {
+		stralloc_free(&tmp);
+		stralloc_free(&currentimg);
+		stralloc_free(&img);
+		strerr_diefu(111, "write to current");
+	}
+	stralloc_free(&tmp);
+
+	url_hpn(&img, &imhost, &impath, &imfile);
+
+	char const *wtimg_argv[] = { "s6-tlsclient", "-N", "--",
+		imhost.s, "443", "mvwtimg", imhost.s, impath.s, imfile.s, 0 };
+
+	xexec(wtimg_argv);
+
+	return 111;
+}