Rename www-cgi to ucgi (in nearly all places)

[userv-utils] / ucgi / ucgi.c

diff --git a/ucgi/ucgi.c b/ucgi/ucgi.c
new file mode 100644 (file)
index 0000000..fc9888b
--- /dev/null
+++ b/ucgi/ucgi.c
@@ -0,0 +1,164 @@
+/*
+ * Usage: as CGI script
+ */
+/*
+ * Copyright 1996-2013,2016 Ian Jackson <ijackson@chiark.greenend.org.uk>
+ * Copyright 1998 David Damerell <damerell@chiark.greenend.org.uk>
+ * Copyright 1999,2003
+ *    Chancellor Masters and Scholars of the University of Cambridge
+ * Copyright 2010 Tony Finch <fanf@dotat.at>
+ * Copyright 2013,2016 Mark Wooding <mdw@distorted.org.uk>
+ *
+ * This is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with userv-utils; if not, see http://www.gnu.org/licenses/.
+ */
+
+#include <stdio.h>
+#include <string.h>
+#include <ctype.h>
+#include <unistd.h>
+#include <sys/types.h>
+#include <sys/wait.h>
+
+#include "ucgi.h"
+
+static const char *const default_envok[] = {
+  "AUTH_TYPE",
+  "CONTENT_TYPE",
+  "CONTENT_LENGTH",
+  "DOCUMENT_ROOT",
+  "GATEWAY_INTERFACE",
+  "HTTP_*",
+  "HTTPS",
+  "PATH_INFO",
+  "PATH_TRANSLATED",
+  "QUERY_STRING",
+  "REDIRECT_*",
+  "REMOTE_*",
+  "REQUEST_METHOD",
+  "REQUEST_URI",
+  "SCRIPT_*",
+  "SERVER_*",
+  "SSL_*",
+  0
+};
+
+struct buildargs {
+  const char **v;
+  int n, max;
+};
+
+static void addarg(struct buildargs *args, const char *a) {
+  if (args->n > args->max) error("too many arguments", 500);
+  args->v[args->n++]= a;
+}
+
+static void add_userv_var(const char *fulln,
+                         const char *en, const char *ev, void *p) {
+  struct buildargs *args= p;
+  size_t l;
+  char *a;
+
+  l= strlen(ev);
+  if (l > MAX_ENVVAR_VALUE) error("environment variable too long", 500);
+  a= xmalloc(strlen(en)+l+6);
+  sprintf(a,"-DE_%s=%s",en,ev);
+  addarg(args, a);
+}
+
+int main(int argc, const char **argv) {
+  char *username;
+  const char *slash2, *pathi, *ev, *av;
+  const char *const *envok = 0;
+  size_t usernamelen, l;
+  struct buildargs args;
+  pid_t child, rchild;
+  int status;
+
+  l= strlen(argv[0]);
+  if (l>6 && !strcmp(argv[0]+l-6,"-debug")) debugmode= 1;
+
+  if (debugmode) {
+    if (fputs("Content-Type: text/plain\n\n",stdout)==EOF || fflush(stdout))
+      syserror("write stdout");
+    if (dup2(1,2)<0) { perror("dup stdout to stderr"); exit(-1); }
+    D( printf(";;; UCGI\n"); )
+  }
+  
+  if (argc > MAX_ARGS) error("too many arguments", 500);
+
+  ev= getenv("UCGI_ENV_FILTER");
+  if (ev)
+    envok= load_filters(LOADF_MUST, ev, LF_END);
+  else
+    envok= load_filters(0, "/etc/userv/ucgi.env-filter", LF_END);
+
+  pathi= getenv("PATH_INFO");
+  if (!pathi) error("PATH_INFO not found", 500);
+  D( if (debugmode) {
+       printf(";; find user name...\n"
+             ";;   initial PATH_INFO = `%s'\n",
+             pathi);
+  } )
+  if (pathi[0] != '/' || pathi[1] != '~')
+    error("PATH_INFO must start with /~", 400);
+  slash2= strchr(pathi+2,'/');
+  if (!slash2) error("PATH_INFO must have more than one /", 400);
+  usernamelen= slash2-(pathi+2);
+  if (usernamelen > MAX_USERNAME_LEN) error("PATH_INFO username too long", 400);
+  username= xmalloc(usernamelen+1);
+  memcpy(username,pathi+2,usernamelen); username[usernamelen]= 0;
+  D( if (debugmode)
+       printf(";;   user = `%s'; tail = `%s'\n", username, slash2); )
+  if (!isalpha(username[0]))
+    error("username 1st character is not alphabetic", 400);
+  xsetenv("PATH_INFO",slash2,1);
+
+  args.n= 0; args.max= argc + MAX_ENVVARS + 10;
+  args.v= xmalloc(args.max * sizeof(*args.v));
+  
+  addarg(&args, "userv");
+  if (debugmode) addarg(&args, "-DDEBUG=1");
+
+  filter_environment(FILTF_WILDCARD, "", envok, default_envok,
+                    add_userv_var, &args);
+
+  addarg(&args, username);
+  addarg(&args, "www-cgi");
+  while ((av= (*++argv))) addarg(&args, av);
+  addarg(&args, 0);
+
+  if (debugmode) {
+    D( fflush(stdout); )
+    child= fork(); if (child==-1) syserror("fork");
+    if (child) {
+      rchild= waitpid(child,&status,0);
+      if (rchild==-1) syserror("waitpid");
+      printf("\nexit status %d %d\n",(status>>8)&0x0ff,status&0x0ff);
+      exit(0);
+    }
+  }
+      
+  D( if (debugmode) {
+       int i;
+
+       printf(";; final command line...\n");
+       for (i = 0; args.v[i]; i++)
+        printf(";;   %s\n", args.v[i]);
+       fflush(stdout);
+  } )
+
+  execvp("userv",(char*const*)args.v);
+  syserror("exec userv");
+  return -1;
+}