Add mg_http_next_multipart()

src/http.c

@@ -10,13 +10,55 @@
 #include "ws.h"
 
 // Multipart POST example:
-// https://gist.github.com/cpq/b8dd247571e6ee9c54ef7e8dfcfecf48
-int mg_http_next_multipart(struct mg_str body, int offset,
-                           struct mg_http_part *part) {
-  if (o
-  (void) body;
-  (void) part;
-  return 0;
+// --xyz
+// Content-Disposition: form-data; name="val"
+//
+// abcdef
+// --xyz
+// Content-Disposition: form-data; name="foo"; filename="a.txt"
+// Content-Type: text/plain
+//
+// hello world
+//
+// --xyz--
+size_t mg_http_next_multipart(struct mg_str body, size_t ofs,
+                              struct mg_http_part *part) {
+  struct mg_str cd = mg_str_n("Content-Disposition", 19);
+  const char *s = body.ptr;
+  size_t b = ofs, h1, h2, b1, b2, max = body.len;
+
+  // Init part params
+  if (part != NULL) part->name = part->filename = part->body = mg_str_n(0, 0);
+
+  // Skip boundary
+  while (b + 2 < max && s[b] != '\r' && s[b + 1] != '\n') b++;
+  if (b <= ofs || b + 2 >= max) return 0;
+  // LOG(LL_INFO, ("B: %zu %zu [%.*s]", ofs, b - ofs, (int) (b - ofs), s));
+
+  // Skip headers
+  h1 = h2 = b + 2;
+  for (;;) {
+    while (h2 + 2 < max && s[h2] != '\r' && s[h2 + 1] != '\n') h2++;
+    if (h2 == h1) break;
+    if (h2 + 2 >= max) return 0;
+    // LOG(LL_INFO, ("Header: [%.*s]", (int) (h2 - h1), &s[h1]));
+    if (part != NULL && h1 + cd.len + 2 < h2 && s[h1 + cd.len] == ':' &&
+        mg_ncasecmp(&s[h1], cd.ptr, cd.len) == 0) {
+      struct mg_str v = mg_str_n(&s[h1 + cd.len + 2], h2 - (h1 + cd.len + 2));
+      part->name = mg_http_get_header_var(v, mg_str_n("name", 4));
+      part->filename = mg_http_get_header_var(v, mg_str_n("filename", 8));
+    }
+    h1 = h2 = h2 + 2;
+  }
+  b1 = b2 = h2 + 2;
+  while (b2 + 2 + (b - ofs) + 2 < max && s[b2] != '\r' && s[b2 + 1] != '\n' &&
+         memcmp(&s[b2 + 2], s, b - ofs) != 0)
+    b2++;
+
+  if (b2 + 2 >= max) return 0;
+  if (part != NULL) part->body = mg_str_n(&s[b1], b2 - b1);
+  // LOG(LL_INFO, ("Body: [%.*s]", (int) (b2 - b1), &s[b1]));
+  return b2 + 2;
 }
 
 void mg_http_bauth(struct mg_connection *c, const char *user,
@@ -746,20 +788,31 @@ void mg_http_creds(struct mg_http_message *hm, char *user, int userlen,
   } else if (v != NULL && v->len > 7 && memcmp(v->ptr, "Bearer ", 7) == 0) {
     snprintf(pass, passlen, "%.*s", (int) v->len - 7, v->ptr + 7);
   } else if ((v = mg_http_get_header(hm, "Cookie")) != NULL) {
-    size_t i;
-    for (i = 0; i < v->len - 13; i++) {
-      if (memcmp(&v->ptr[i], "access_token=", 13) == 0) {
-        const char *p2 = v->ptr + i + 13, *p3 = p2;
-        while (p2 < &v->ptr[v->len] && p2[0] != ';' && p2[0] != ' ') p2++;
-        snprintf(pass, passlen, "%.*s", (int) (p2 - p3), p3);
-        break;
-      }
-    }
+    struct mg_str t = mg_http_get_header_var(*v, mg_str_n("access_token", 12));
+    if (t.len > 0) snprintf(pass, passlen, "%.*s", (int) t.len, t.ptr);
   } else {
     mg_http_get_var(&hm->query, "access_token", pass, passlen);
   }
 }
 
+static struct mg_str stripquotes(struct mg_str s) {
+  return s.len > 1 && s.ptr[0] == '"' && s.ptr[s.len - 1] == '"'
+             ? mg_str_n(s.ptr + 1, s.len - 2)
+             : s;
+}
+
+struct mg_str mg_http_get_header_var(struct mg_str s, struct mg_str v) {
+  size_t i;
+  for (i = 0; i + v.len + 2 < s.len; i++) {
+    if (s.ptr[i + v.len] == '=' && memcmp(&s.ptr[i], v.ptr, v.len) == 0) {
+      const char *p2 = &s.ptr[i + v.len + 1], *p3 = p2;
+      while (p2 < &s.ptr[s.len] && p2[0] != ';' && p2[0] != ' ') p2++;
+      return stripquotes(mg_str_n(p3, p2 - p3));
+    }
+  }
+  return mg_str_n(NULL, 0);
+}
+
 bool mg_http_match_uri(const struct mg_http_message *hm, const char *glob) {
   return mg_globmatch(glob, strlen(glob), hm->uri.ptr, hm->uri.len);
 }

src/http.h

@@ -32,7 +32,7 @@ struct mg_http_serve_opts {
 struct mg_http_part {
   struct mg_str name;      // Form field name
   struct mg_str filename;  // Filename for file uploads
-  struct mg_str part;      // Part contents
+  struct mg_str body;      // Part contents
 };
 
 int mg_http_parse(const char *s, size_t len, struct mg_http_message *);
@@ -60,4 +60,5 @@ bool mg_http_match_uri(const struct mg_http_message *, const char *glob);
 int mg_http_upload(struct mg_connection *, struct mg_http_message *hm,
                    const char *dir);
 void mg_http_bauth(struct mg_connection *, const char *user, const char *pass);
-int mg_http_next_multipart(struct mg_str, int, struct mg_http_part *);
+struct mg_str mg_http_get_header_var(struct mg_str s, struct mg_str v);
+size_t mg_http_next_multipart(struct mg_str, size_t, struct mg_http_part *);