Add SSI include file=, include virtual=

src/ssi.c

@@ -0,0 +1,83 @@
+#include "log.h"
+#include "ssi.h"
+
+#ifndef MG_MAX_SSI_DEPTH
+#define MG_MAX_SSI_DEPTH 5
+#endif
+
+#if MG_ENABLE_SSI
+static char *mg_ssi(const char *path, const char *root, int depth) {
+  struct mg_iobuf b = {NULL, 0, 0};
+  FILE *fp = fopen(path, "rb");
+  if (fp != NULL) {
+    char buf[BUFSIZ], arg[sizeof(buf)];
+    int ch, intag = 0;
+    size_t len = 0, align = MG_IO_SIZE;
+    while ((ch = fgetc(fp)) != EOF) {
+      if (intag && ch == '>' && buf[len - 1] == '-' && buf[len - 2] == '-') {
+        buf[len++] = ch & 0xff;
+        if (sscanf(buf, "<!--#include file=\"%[^\"]", arg)) {
+          char tmp[PATH_MAX], *p = (char *) path + strlen(path), *data;
+          while (p > path && p[-1] != MG_DIRSEP && p[-1] != '/') p--;
+          snprintf(tmp, sizeof(tmp), "%.*s%s", (int) (p - path), path, arg);
+          if (depth < MG_MAX_SSI_DEPTH &&
+              (data = mg_ssi(tmp, root, depth + 1)) != NULL) {
+            mg_iobuf_append(&b, data, strlen(data), align);
+            free(data);
+          } else {
+            LOG(LL_ERROR, ("%s: file=%s error or too deep", path, arg));
+          }
+        } else if (sscanf(buf, "<!--#include virtual=\"%[^\"]", arg)) {
+          char tmp[PATH_MAX], *data;
+          snprintf(tmp, sizeof(tmp), "%s%s", root, arg);
+          if (depth < MG_MAX_SSI_DEPTH &&
+              (data = mg_ssi(tmp, root, depth + 1)) != NULL) {
+            mg_iobuf_append(&b, data, strlen(data), align);
+            free(data);
+          } else {
+            LOG(LL_ERROR, ("%s: virtual=%s error or too deep", path, arg));
+          }
+        } else {
+          // Unknown SSI tag
+          LOG(LL_INFO, ("Unknown SSI tag: %.*s", (int) len, buf));
+          mg_iobuf_append(&b, buf, len, align);
+        }
+        intag = 0;
+        len = 0;
+      } else if (ch == '<') {
+        intag = 1;
+        if (len > 0) mg_iobuf_append(&b, buf, len, align);
+        len = 0;
+        buf[len++] = ch & 0xff;
+      } else if (intag) {
+        if (len == 5 && strncmp(buf, "<!--#", 5) != 0) {
+          intag = 0;
+        } else if (len >= sizeof(buf) - 2) {
+          LOG(LL_ERROR, ("%s: SSI tag is too large", path));
+          len = 0;
+        }
+        buf[len++] = ch & 0xff;
+      } else {
+        buf[len++] = ch & 0xff;
+        if (len >= sizeof(buf)) {
+          mg_iobuf_append(&b, buf, len, align);
+          len = 0;
+        }
+      }
+    }
+    if (len > 0) mg_iobuf_append(&b, buf, len, align);
+    if (b.len > 0) mg_iobuf_append(&b, "", 1, align);  // nul-terminate
+    fclose(fp);
+  }
+  (void) depth;
+  (void) root;
+  return (char *) b.buf;
+}
+
+void mg_http_serve_ssi(struct mg_connection *c, const char *root,
+                       const char *fullpath) {
+  char *data = mg_ssi(fullpath, root, 0);
+  mg_http_reply(c, 200, "", "%s", data == NULL ? "" : data);
+  free(data);
+}
+#endif