Impl CGI redirectsHEADdev

2 files changed, 214 insertions, 22 deletions

diff --git a/compile_flags.txt b/compile_flags.txt
deleted file mode 100644
index 1a27fb0..0000000
--- a/compile_flags.txt
+++ /dev/null
@@ -1,4 +0,0 @@
--Wall
--Wextra
--Werror
--pedantic
diff --git a/main.c b/main.c
index 7ade799..9949195 100755
--- a/main.c
+++ b/main.c
@@ -70,6 +70,10 @@ exit $? # */
 #include <stdlib.h>
 #include <string.h>
 #include <time.h>
+#include <signal.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <sys/wait.h>
 
 //  ================================================================
 //
@@ -156,8 +160,17 @@ typedef struct {
 } Location;
 
 typedef struct {
-  c8 const *alias;
-  c8 const *url;
+  b8 END;
+  c8 const *name;
+  c8 const *value;
+} Replace_Header;
+
+typedef struct {
+  c8 const *      alias;
+  c8 const *      url;
+  c8 *            cgi;
+  b8              is_binary;
+  Replace_Header *replace_headers;
 } Redirect;
 
 //  ================================================================
@@ -492,7 +505,36 @@ static Redirect redirects[] = {
   }, {
     .alias = "/deezer/2021",
     .url   = "https://deezer.page.link/PXS8q1jEqECa79rEA",
-  },
+  }, {
+    .alias = "/juliaset",
+    .url   = "/static/plain/juliaset/index.htm",
+    .cgi   = "/usr/lib/cgit/cgit.cgi",
+    .replace_headers = (Replace_Header[]) {
+      { .name = "Content-Type", .value = "text/html; charset=UTF-8", },
+      { .name = "X-Content-Type-Options",  .value = NULL, },
+      { .name = "Content-Security-Policy", .value = NULL, },
+      { .name = "Content-Disposition",     .value = NULL, },
+      { .name = "Last-Modified",           .value = NULL, },
+      { .name = "Expires",                 .value = NULL, },
+      { .name = "ETag",                    .value = NULL, },
+      { .END=1, }
+    },
+  }, {
+    .alias = "/juliaset/julia_set.wasm",
+    .url   = "/static/plain/juliaset/julia_set.wasm",
+    .cgi   = "/usr/lib/cgit/cgit.cgi",
+    .is_binary       = 1,
+    .replace_headers = (Replace_Header[]) {
+      { .name = "Content-Type", .value = "application/wasm", },
+      { .name = "X-Content-Type-Options",  .value = NULL, },
+      { .name = "Content-Security-Policy", .value = NULL, },
+      { .name = "Content-Disposition",     .value = NULL, },
+      { .name = "Last-Modified",           .value = NULL, },
+      { .name = "Expires",                 .value = NULL, },
+      { .name = "ETag",                    .value = NULL, },
+      { .END=1, }
+    },
+   }
 };
 
 static Location locs[] = {
@@ -2391,12 +2433,67 @@ c8 const *headlines[] = {
   "A renaissance of the Pythagorean mindset.",
 };
 
+c8  cgi_output[1024 * 1024 * 10] = {0};
+i32 cgi_output_size              = 0;
+
 //  ================================================================
 //
 //   Procedures
 //
 //  ================================================================
 
+i32 run_cgi(c8 const *cgi, c8 *const *argv, c8 *const *envp) {
+  signal(SIGCHLD, SIG_IGN);
+  signal(SIGALRM, SIG_IGN);
+
+  i32 pipe_out[2];
+
+  if (pipe(pipe_out) == -1)
+    return 1;
+
+  if (fcntl(pipe_out[1], F_SETFL, O_NONBLOCK) == -1)
+    return 2;
+
+  pid_t id = fork();
+
+  switch (id) {
+    case -1:
+      return 3;
+
+    case 0:
+      if (dup2(pipe_out[1], STDOUT_FILENO) == -1)
+        return 4;
+
+      close(pipe_out[0]);
+      close(pipe_out[1]);
+
+      execve(cgi, argv, envp);
+      return 5;
+
+    default:;
+  }
+
+  for (;;) {
+    int status;
+
+    if (waitpid(id, &status, 0) == -1)
+      break;
+
+    if (WIFEXITED(status))
+      break;
+  }
+
+  i64 n = read(pipe_out[0], cgi_output, sizeof cgi_output - 1);
+
+  if (n <= 0)
+    return 6;
+
+  cgi_output[n]   = '\0';
+  cgi_output_size = n;
+
+  return 0;
+}
+
 c8 const *get_color(i32 index) {
   static i64 rainbow_index = -1;
   if (rainbow_index == -1)
@@ -3091,7 +3188,7 @@ void setup_theme_cookie(c8 const *cookie, c8 const *query) {
              COLORS[i][5]);
     printf("; Path=/; SameSite=Lax; Expires=");
     print_time_gmt(6 * SECONDS_IN_MONTH);
-    printf("; HttpOnly\n");
+    printf("; HttpOnly\r\n");
   }
 }
 
@@ -3099,6 +3196,11 @@ i32 main(i32 argc, c8 **argv) {
   (void) argc;
   (void) argv;
 
+  FILE *_in  = freopen(NULL, "rb", stdin);
+  FILE *_out = freopen(NULL, "wb", stdout);
+  (void) _in;
+  (void) _out;
+
   struct timespec time_begin;
 
   timespec_get(&time_begin, TIME_UTC);
@@ -3119,19 +3221,19 @@ i32 main(i32 argc, c8 **argv) {
        strlen(content_type)   > MAX_CONTENT_TYPE_SIZE   ||
       (!str_eq(request_method, NULL, "GET", NULL) &&
        !str_eq(request_method, NULL, "POST", NULL))) {
-    printf("Status: 500 Internal Server Error\n");
+    printf("Status: 500 Internal Server Error 1\r\n");
     return 0;
   }
 
   //  TODO Check blacklist and throttling
 
   if (0) {
-    printf("Status: 400 Forbidden\n");
+    printf("Status: 400 Forbidden\r\n");
     return 0;
   }
 
   if (0) {
-    printf("Status: 429 Too Many Requests\n");
+    printf("Status: 429 Too Many Requests\r\n");
     return 0;
   }
 
@@ -3139,12 +3241,104 @@ i32 main(i32 argc, c8 **argv) {
 
   for (i64 i = 0; i < (i64)(sizeof redirects / sizeof *redirects); ++i)
     if (str_eq_with_slash(document_uri, redirects[i].alias)) {
-      printf("Status: 301 Redirect\n");
-      printf("Location: %s\n", redirects[i].url);
-      printf("Content-Type: text/html\n");
-      printf("\n");
-      printf("Redirect: <a href='%s'>%s</a>\n", redirects[i].url, redirects[i].url);
-      return 0;
+      if (redirects[i].url == NULL) {
+        printf("Status: 500 Internal Server Error 2\r\n");
+        return 0;
+      }
+
+      if (redirects[i].cgi != NULL) {
+        static c8 buf[4096] = {0};
+        snprintf(buf, sizeof buf - 1, "PATH_INFO=%s", redirects[i].url);
+
+        c8 *argv[] = { redirects[i].cgi, NULL };
+        c8 *envp[] = { buf, NULL };
+
+        i32 s = run_cgi(redirects[i].cgi, argv, envp);
+        if (s != 0) {
+          printf("Status: 500 Internal Server Error %d\r\n", s);
+          return 0;
+        }
+
+        printf("Status: 200 OK\r\n");
+        printf("Cross-Origin-Opener-Policy: same-origin\r\n");
+        printf("Cross-Origin-Embedder-Policy: require-corp\r\n");
+
+        c8 *p = cgi_output;
+
+        while (p < cgi_output + cgi_output_size) {
+          if (*p == '\r' || *p == '\n') {
+            printf("\r\n");
+            if (*p == '\r') ++p;
+            if (*p == '\n') ++p;
+            break;
+          }
+
+          c8 *q = p;
+          while (q < cgi_output + cgi_output_size && *q != '\r' && *q != '\n')
+            ++q;
+          if (q[0] == '\r' && q[1] == '\n') {
+            ++q;
+            *q = '\0';
+          }
+          *q = '\0';
+
+          b8 replaced = 0;
+
+          for (i32 j = 0;; ++j) {
+            if (redirects[i].replace_headers[j].END)
+              break;
+
+            c8 const *name  = redirects[i].replace_headers[j].name;
+            c8 const *value = redirects[i].replace_headers[j].value;
+
+            if (name == NULL)
+              continue;
+
+            i32 len = strlen(name);
+
+            if (q - p > len && p[len] == ':' && str_eq(p, p + len, name, name + len)) {
+              if (value != NULL)
+                printf("%s: %s\r\n", name, value);
+              replaced = 1;
+              break;
+            }
+          }
+
+          if (!replaced)
+            printf("%s\r\n", p);
+
+          p = q + 1;
+        }
+
+        if (redirects[i].is_binary) {
+          fflush(stdout);
+          i32 written = write(STDOUT_FILENO, p, (cgi_output + cgi_output_size) - p);
+          (void) written;
+        } else
+          while (p < cgi_output + cgi_output_size) {
+            c8 *q = p;
+            while (q < cgi_output + cgi_output_size && *q != '\r' && *q != '\n')
+              ++q;
+            if (q[0] == '\r' && q[1] == '\n') {
+              ++q;
+              *q = '\0';
+            }
+            *q = '\0';
+
+            printf("%s\r\n", p);
+
+            p = q + 1;
+          }
+
+        return 0;
+      } else {
+        printf("Status: 301 Redirect\r\n");
+        printf("Location: %s\r\n", redirects[i].url);
+        printf("Content-Type: text/html; charset=UTF-8\r\n");
+        printf("\r\n");
+        printf("Redirect: <a href='%s'>%s</a>\r\n", redirects[i].url, redirects[i].url);
+        return 0;
+      }
     }
 
   for (i64 i = 0; i < (i64)(sizeof locs / sizeof *locs); ++i)
@@ -3155,14 +3349,16 @@ i32 main(i32 argc, c8 **argv) {
     }
 
   if (doc == DOC_404)
-    printf("Status: 404 Page Not Found\n");
+    printf("Status: 404 Page Not Found\r\n");
   else
-    printf("Status: 200 OK\n");
+    printf("Status: 200 OK\r\n");
 
   setup_theme_cookie(http_cookie, query_string);
 
-  printf("Content-Type: text/html\n");
-  printf("\n");
+  printf("Cross-Origin-Opener-Policy: same-origin\r\n");
+  printf("Cross-Origin-Embedder-Policy: require-corp\r\n");
+  printf("Content-Type: text/html\r\n");
+  printf("\r\n");
 
   if (docs[doc].content[0].type == TAG_RAW) {
     printf("%s", docs[doc].content[0].text);
@@ -3330,7 +3526,7 @@ i32 main(i32 argc, c8 **argv) {
          "</script>",
           delta_micros / 1000,
          (delta_micros / 10) % 100);
-  printf("\n");
+  printf("\r\n");
 
   return 0;
 }