Initial commit

Signed-off-by: Laurent Bercot <ska@appnovation.com>

1 files changed, 381 insertions, 0 deletions

diff --git a/src/tipideed/cgi.c b/src/tipideed/cgi.c
new file mode 100644
index 0000000..7a3ca03
--- /dev/null
+++ b/src/tipideed/cgi.c
@@ -0,0 +1,381 @@
+/* ISC license. */
+
+#include <unistd.h>
+#include <string.h>
+#include <strings.h>
+#include <errno.h>
+#include <signal.h>
+
+#include <skalibs/gccattributes.h>
+#include <skalibs/posixplz.h>
+#include <skalibs/types.h>
+#include <skalibs/bytestr.h>
+#include <skalibs/buffer.h>
+#include <skalibs/error.h>
+#include <skalibs/allreadwrite.h>
+#include <skalibs/strerr.h>
+#include <skalibs/stralloc.h>
+#include <skalibs/djbunix.h>
+#include <skalibs/iopause.h>
+#include <skalibs/env.h>
+#include <skalibs/exec.h>
+#include <skalibs/unix-timed.h>
+#include <skalibs/lolstdio.h>
+
+#include <tipidee/method.h>
+#include <tipidee/headers.h>
+#include <tipidee/response.h>
+#include <tipidee/uri.h>
+#include "tipideed-internal.h"
+
+static void addenv_ (tipidee_rql const *rql, char const *k, char const *v, int slash)
+{
+  if (!stralloc_cats(&g.sa, k)
+   || !stralloc_catb(&g.sa, "=/", 1 + !!slash)
+   || !stralloc_cats(&g.sa, v)
+   || !stralloc_0(&g.sa))
+    die500sys(rql, 111, "stralloc_catb") ;
+}
+
+#define addenv(rql, k, v) addenv_(rql, k, (v), 0)
+#define addenvslash(rql, k, v) addenv_(rql, k, (v), 1)
+
+static void delenv (tipidee_rql const *rql, char const *k)
+{
+  if (!stralloc_cats(&g.sa, k)
+   || !stralloc_0(&g.sa))
+    die500sys(rql, 111, "stralloc_catb") ;
+}
+
+static inline void modify_env (tipidee_rql const *rql, tipidee_headers const *hdr, size_t cl, char const *script, char const *infopath)
+{
+  uint32_t got = 0 ;
+  addenv(rql, "REQUEST_METHOD", tipidee_method_tostr(rql->m)) ;
+  if (cl)
+  {
+    char fmt[SIZE_FMT] ;
+    fmt[size_fmt(fmt, cl)] = 0 ;
+    addenv(rql, "CONTENT_LENGTH", fmt) ;
+  }
+  else delenv(rql, "CONTENT_LENGTH") ;
+
+  if (infopath) addenvslash(rql, "PATH_INFO", infopath) ;
+  else delenv(rql, "PATH_INFO") ;
+  if (rql->uri.query) addenv(rql, "QUERY_STRING", rql->uri.query) ;
+  else delenv(rql, "QUERY_STRING") ;
+  addenv(rql, "SCRIPT_NAME", script) ;
+  
+  for (size_t i = 0 ; i < hdr->n ; i++)
+  {
+    char const *key = hdr->buf + hdr->list[i].left ;
+    char const *val = hdr->buf + hdr->list[i].right ;
+    if (!strcasecmp(key, "Authorization"))
+    {
+      size_t n = str_chr(val, ' ') ;
+      if (n)
+      {
+        char scheme[n] ;
+        memcpy(scheme, val, n-1) ;
+        scheme[n-1] = 0 ;
+        addenv(rql, "AUTH_TYPE", scheme) ;
+        got |= 1 ;
+      }
+    }
+    else if (!strcasecmp(key, "Content-Type")) { addenv(rql, "CONTENT_TYPE", val) ; got |= 2 ; }
+    else if (!strcasecmp(key, "Content-Length") || !strcasecmp(key, "Connection")) ;
+    else
+    {
+      size_t len = strlen(key), pos = g.sa.len + 5 ;
+      if (!stralloc_catb(&g.sa, "HTTP_", 5)) die500sys(rql, 111, "stralloc_catb") ;
+      addenv(rql, key, val) ;
+      for (char *s = g.sa.s + pos ; len-- ; s++)
+        if (*s == '-') *s = '_' ;
+        else if (*s >= 'a' && *s <= 'z') *s -= 32 ;
+    }
+  }
+  if (!(got & 1)) delenv(rql, "AUTH_TYPE") ;
+  if (!(got & 2)) delenv(rql, "CONTENT_TYPE") ;
+}
+
+static inline int do_nph (tipidee_rql const *rql, char const *const *argv, char const *const *envp, char const *body, size_t bodylen) gccattr_noreturn ;
+static inline int do_nph (tipidee_rql const *rql, char const *const *argv, char const *const *envp, char const *body, size_t bodylen)
+{
+  int p[2] ;
+  log_nph(argv, envp) ;
+  if (pipe(p) == -1) die500sys(rql, 111, "pipe") ;
+  if (bodylen)
+  {
+    switch (fork())
+    {
+      case -1 : die500sys(rql, 111, "fork") ;
+      case 0 :      
+      {
+        tain deadline ;
+        char buf[4096] ;
+        buffer b = BUFFER_INIT(&buffer_write, p[1], buf, 4096) ;
+        PROG = "tipidee (nph helper child)" ;
+        tain_add_g(&deadline, &g.cgitto) ;
+        close(p[0]) ;
+        if (ndelay_on(p[1]) == -1) strerr_diefu1sys(111, "set fd nonblocking") ;
+        if (buffer_timed_put_g(&b, body, bodylen, &deadline) < bodylen
+         || !buffer_timed_flush_g(&b, &deadline))
+          strerr_diefu2sys(111, "write request body to nph ", argv[0]) ;
+        _exit(0) ;
+      }
+      default : break ;
+    }
+  }
+  close(p[1]) ;
+  if (fd_move(0, p[0]) == -1) die500sys(rql, 111, "fd_move") ;
+  exec_e(argv, envp) ;
+  die500sys(rql, errno == ENOENT ? 127 : 126, "exec nph ", argv[0]) ;
+}
+
+static inline int run_cgi (tipidee_rql const *rql, char const *const *argv, char const *const *envp, char const *body, size_t bodylen, tipidee_headers *hdr, stralloc *sa)
+{
+  iopause_fd x[2] = { { .events = IOPAUSE_READ }, { .events = IOPAUSE_WRITE } } ;
+  size_t bodyw = 0 ;
+  unsigned int rstate = 0 ;
+  tain deadline ;
+  pid_t pid ;
+  disize curheader = DISIZE_ZERO ;
+  uint32_t parserstate = 0 ;
+  buffer b ;
+  char buf[4096] ;
+  log_cgi(argv, envp) ;
+  {
+    int fd[2] = { 0, 1 } ;
+    pid = child_spawn2(argv[0], argv, envp, fd) ;
+    if (!pid) die500sys(rql, 111, "spawn ", argv[0]) ;
+    x[0].fd = fd[0] ; x[1].fd = fd[1] ;
+  }
+  if (!bodylen)
+  {
+    close(x[1].fd) ;
+    x[1].fd = -1 ;
+    LOLDEBUG("run_cgi: no request body, closing writing pipe to cgi") ;
+  }
+  buffer_init(&b, &buffer_read, x[0].fd, buf, 4096) ;
+  tain_add_g(&deadline, &g.cgitto) ;
+  while (x[0].fd >= 0)
+  {
+    int r = iopause_g(x, 1 + (x[1].fd >= 0), &deadline) ;
+    if (r == -1) die500sys(rql, 111, "iopause") ;
+    if (!r)
+    {
+      kill(pid, SIGTERM) ;
+      respond_504(rql) ;
+      break ;
+    }
+    if (x[1].fd >= 0 && x[1].revents & (IOPAUSE_WRITE | IOPAUSE_EXCEPT))
+    {
+      size_t len = allwrite(x[1].fd, body + bodyw, bodylen - bodyw) ;
+      if (!len)
+      {
+        if (g.verbosity) strerr_warnwu2sys("write request body to cgi ", argv[0]) ;
+        bodyw = bodylen ;
+      }
+      else bodyw += len ;
+      if (bodyw >= bodylen)
+      {
+        close(x[1].fd) ;
+        x[1].fd = -1 ;
+        LOLDEBUG("run_cgi: finished writing body") ;
+      }
+    }
+    if (x[0].fd >= 0 && x[0].revents & (IOPAUSE_READ | IOPAUSE_EXCEPT))
+    {
+      switch (rstate)
+      {
+        case 0 :
+        {
+          r = tipidee_headers_parse_nb(&b, hdr, &curheader, &parserstate) ;
+          switch (r)
+          {
+            case -2 : break ;
+            case -1 : die500sys(rql, 111, "read from cgi ", argv[0]) ;
+            case 0 :
+            {
+              size_t n = buffer_len(&b) ;
+              if (!stralloc_readyplus(sa, n)) die500sys(rql, 111, "stralloc_readyplus") ;
+              buffer_getnofill(&b, sa->s + sa->len, n) ;
+              sa->len += n ;
+              rstate = 1 ;
+              break ;
+            }
+            case 400 : die502x(rql, 1, "invalid headers", " from cgi ", argv[0]) ;
+            case 413 : die502x(rql, 1, hdr->n >= TIPIDEE_HEADERS_MAX ? "Too many headers" : "Too much header data", " from cgi ", argv[0]) ;
+            case 500 : die500x(rql, 101, "can't happen: ", "avltreen_insert failed", " in do_cgi") ;
+            default : die500x(rql, 101, "can't happen: ", "unknown tipidee_headers_parse return code", " in do_cgi") ;
+          }
+          if (!rstate) break ;
+        }
+        case 1 :
+        {
+          if (!slurpn(x[0].fd, sa, g.maxcgibody))
+          {
+            if (error_isagain(errno)) break ;
+            else if (errno == ENOBUFS) die502x(rql, 1, "Too fat body", " from cgi ", argv[0]) ;
+            else die500sys(rql, 111, "read body", " from cgi ", argv[0]) ;
+          }
+          close(x[0].fd) ;
+          x[0].fd = -1 ;
+          rstate = 2 ;
+          LOLDEBUG("run_cgi: rstate = 2") ;
+        }
+      }
+    }
+  }
+  if (x[1].fd >= 0) close(x[1].fd) ;
+  if (x[0].fd >= 0) close(x[0].fd) ;
+  return rstate == 2 ;
+}
+
+static inline int local_redirect (tipidee_rql *rql, char const *loc, char *uribuf, char const *cginame)
+{
+  size_t n ;
+  size_t hostlen = strlen(rql->uri.host) ;
+  uint16_t port = rql->uri.port ;
+  uint8_t ishttps = rql->uri.https ;
+  char hosttmp[hostlen + 1] ;
+  memcpy(hosttmp, rql->uri.host, hostlen + 1) ;
+  n = tipidee_uri_parse(uribuf, URI_BUFSIZE, loc, &rql->uri) ;
+  if (!n || n + hostlen + 1 > URI_BUFSIZE)
+    die502x(rql, 1, "cgi ", cginame, " returned an invalid ", "Location", " value", " for local redirection") ;
+  memcpy(uribuf + n, hosttmp, hostlen + 1) ;
+  rql->uri.host = uribuf + n ;
+  rql->uri.port = port ;
+  rql->uri.https = ishttps ;
+  return 1 ;
+}
+
+static inline void print_cgi_headers (tipidee_headers const *hdr, size_t rbodylen)
+{
+  static char const *const nope_table[] =
+  {
+    "Connection",
+    "Date",
+    "Status",
+    "Content-Length",
+    0
+  } ;
+  for (size_t i = 0 ; i < hdr->n ; i++)
+  {
+    char const *key = hdr->buf + hdr->list[i].left ;
+    char const *const *p = nope_table ;
+    if (tipidee_response_header_builtin_search(key)) continue ;
+    if (str_start(key, "X-CGI-")) continue ;
+    for (; *p ; p++) if (!strcasecmp(key, *p)) break ;
+    if (*p) continue ;
+    buffer_putsnoflush(buffer_1, key) ;
+    buffer_putnoflush(buffer_1, ": ", 2) ;
+    buffer_putsnoflush(buffer_1, hdr->buf + hdr->list[i].right) ;
+    buffer_putnoflush(buffer_1, "\r\n", 2) ;
+  }
+  if (rbodylen)
+  {
+    char fmt[SIZE_FMT] ;
+    fmt[size_fmt(fmt, rbodylen)] = 0 ;
+    buffer_putsnoflush(buffer_1, "Content-Length: ") ;
+    buffer_putsnoflush(buffer_1, fmt) ;
+    buffer_putnoflush(buffer_1, "\r\n", 2) ;
+  }
+}
+
+static inline int process_cgi_output (tipidee_rql *rql, tipidee_headers const *hdr, char const *rbody, size_t rbodylen, char *uribuf, char const *cginame)
+{
+  char const *location = tipidee_headers_search(hdr, "Location") ;
+  char const *x = tipidee_headers_search(hdr, "Status") ;
+  char const *reason_phrase = "OK" ;
+  unsigned int status = 0 ;
+  tain deadline ;
+  tain_add_g(&deadline, &g.writetto) ;
+  if (x)
+  {
+    size_t m = uint_scan(x, &status) ;
+    if (!m || x[m] != ' ')
+      die502x(rql, 1, "cgi ", cginame, " returned an invalid ", "Status", " header") ;
+    reason_phrase = x + m + 1 ;
+    if (status >= 300 && status < 399 && !location)
+      die502x(rql, 1, "cgi ", cginame, " returned a 3xx status code without a ", "Location", " header") ;
+    if (status < 100 || status > 999)
+      die502x(rql, 1, "cgi ", cginame, " returned an invalid ", "Status", " value") ;
+  }
+  if (location)
+  {
+    if (!location[0]) die502x(rql, 1, "cgi ", cginame, " returned an invalid ", "Location", " header") ;
+    if (location[0] == '/' && location[1] != '/') return local_redirect(rql, location, uribuf, cginame) ;
+    if (rbodylen)
+    {
+      if (!status)
+        die502x(rql, 1, "cgi ", cginame, " didn't output a ", "Status", " header", " for a client redirect response with document") ;
+      if (status < 300 || status > 399)
+        die502x(rql, 1, "cgi ", cginame, " returned an invalid ", "Status", " value", " for a client redirect response with document") ;
+    }
+    else
+    {
+      for (size_t i = 0 ; i < hdr->n ; i++)
+      {
+        char const *key = hdr->buf + hdr->list[i].left ;
+        if (!strcasecmp(key, "Location")) continue ;
+        if (str_start(key, "X-CGI-")) continue ;
+        die502x(rql, 1, "cgi ", cginame, "returned extra headers", " for a client redirect response without document") ;
+      }
+      status = 302 ;
+      reason_phrase = "Found" ;
+    }
+  }
+  else
+  {
+    if (!status) status = 200 ;
+    if (!tipidee_headers_search(hdr, "Content-Type"))
+      die502x(rql, 1, "cgi ", cginame, " didn't output a ", "Content-Type", " header") ;
+  }
+  x = tipidee_headers_search(hdr, "Content-Length") ;
+  if (x)
+  {
+    size_t cln ;
+    if (!size0_scan(x, &cln))
+      die502x(rql, 1, "cgi ", cginame, " returned an invalid ", "Content-Length", " header") ;
+    if (cln != rbodylen)
+      die502x(rql, 1, "cgi ", cginame, " returned a mismatching ", "Content-Length", " header") ;
+  }
+
+  tipidee_response_status(buffer_1, rql, status, reason_phrase) ;
+  tipidee_response_header_common_put_g(buffer_1, !g.cont) ;
+  print_cgi_headers(hdr, rbodylen) ;
+  if (buffer_timed_put_g(buffer_1, "\r\n", 2, &deadline) < 2)
+    strerr_diefu1sys(111, "write to stdout") ;
+  if (rbodylen)
+  {
+    if (buffer_timed_put_g(buffer_1, rbody, rbodylen, &deadline) < rbodylen)
+      strerr_diefu1sys(111, "write to stdout") ;
+  }
+  if (!buffer_timed_flush_g(buffer_1, &deadline))
+    strerr_diefu1sys(111, "write to stdout") ;
+  return 0 ;
+}
+
+static inline int do_cgi (tipidee_rql *rql, char const *const *argv, char const *const *envp, char const *body, size_t bodylen, char *uribuf)
+{
+  static stralloc sa = STRALLOC_ZERO ;
+  tipidee_headers hdr ;
+  char hdrbuf[2048] ;
+  sa.len = 0 ;
+  tipidee_headers_init(&hdr, hdrbuf, 2048) ;
+  if (!run_cgi(rql, argv, envp, body, bodylen, &hdr, &sa)) return 0 ;
+  return process_cgi_output(rql, &hdr, sa.s, sa.len, uribuf, argv[0]) ;
+}
+
+int respond_cgi (tipidee_rql *rql, char const *fn, size_t docrootlen, char const *infopath, char *uribuf, tipidee_headers const *hdr, tipidee_resattr const *ra, char const *body, size_t bodylen)
+{
+  size_t sabase = g.sa.len ;
+  size_t envmax = g.envlen + 16 + TIPIDEE_HEADERS_MAX ;
+  char const *argv[2] = { fn, 0 } ;
+  char const *envp[envmax] ;
+  modify_env(rql, hdr, bodylen, fn + docrootlen, infopath) ;
+  env_merge(envp, envmax, (char const *const *)environ, g.envlen, g.sa.s + g.cwdlen + 1, g.sa.len - (g.cwdlen+1)) ;
+  g.sa.len = sabase ;
+  return ra->isnph ? do_nph(rql, argv, envp, body, bodylen) :
+                     do_cgi(rql, argv, envp, body, bodylen, uribuf) ;
+}