Factor out common request functionality, in preparation for supporting different protocols

1 files changed, 467 insertions, 0 deletions

diff --git a/src/c/request.c b/src/c/request.c
new file mode 100644
index 00000000..b13c6118
--- /dev/null
+++ b/src/c/request.c
@@ -0,0 +1,467 @@
+#define _GNU_SOURCE
+
+#include <stdio.h>
+#include <string.h>
+#include <stdlib.h>
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <netinet/in.h>
+#include <unistd.h>
+#include <signal.h>
+
+#include <pthread.h>
+
+#include <mhash.h>
+
+#include "urweb.h"
+
+#define MAX_RETRIES 5
+
+static int try_rollback(uw_context ctx) {
+  int r = uw_rollback(ctx);
+
+  if (r) {
+    printf("Error running SQL ROLLBACK\n");
+    uw_reset(ctx);
+    uw_write(ctx, "HTTP/1.1 500 Internal Server Error\n\r");
+    uw_write(ctx, "Content-type: text/plain\r\n\r\n");
+    uw_write(ctx, "Error running SQL ROLLBACK\n");
+  }
+
+  return r;
+}
+
+uw_context uw_request_new_context() {
+  uw_context ctx = uw_init();
+  int retries_left = MAX_RETRIES;
+
+  while (1) {
+    failure_kind fk = uw_begin_init(ctx);
+
+    if (fk == SUCCESS) {
+      printf("Database connection initialized.\n");
+      break;
+    } else if (fk == BOUNDED_RETRY) {
+      if (retries_left) {
+        printf("Initialization error triggers bounded retry: %s\n", uw_error_message(ctx));
+        --retries_left;
+      } else {
+        printf("Fatal initialization error (out of retries): %s\n", uw_error_message(ctx));
+        uw_free(ctx);
+        return NULL;
+      }
+    } else if (fk == UNLIMITED_RETRY)
+      printf("Initialization error triggers unlimited retry: %s\n", uw_error_message(ctx));
+    else if (fk == FATAL) {
+      printf("Fatal initialization error: %s\n", uw_error_message(ctx));
+      uw_free(ctx);
+      return NULL;
+    } else {
+      printf("Unknown uw_begin_init return code!\n");
+      uw_free(ctx);
+      return NULL;
+    }
+  }
+
+  return ctx;
+}
+
+#define KEYSIZE 16
+#define PASSSIZE 4
+
+#define HASH_ALGORITHM MHASH_SHA256
+#define HASH_BLOCKSIZE 32
+#define KEYGEN_ALGORITHM KEYGEN_MCRYPT
+
+int uw_hash_blocksize = HASH_BLOCKSIZE;
+
+static int password[PASSSIZE];
+static unsigned char private_key[KEYSIZE];
+
+static void init_crypto() {
+  KEYGEN kg = {{HASH_ALGORITHM, HASH_ALGORITHM}};
+  int i;
+
+  assert(mhash_get_block_size(HASH_ALGORITHM) == HASH_BLOCKSIZE);
+
+  for (i = 0; i < PASSSIZE; ++i)
+    password[i] = rand();
+
+  if (mhash_keygen_ext(KEYGEN_ALGORITHM, kg,
+                       private_key, sizeof(private_key),
+                       (unsigned char*)password, sizeof(password)) < 0) {
+    printf("Key generation failed\n");
+    exit(1);
+  }
+}
+
+void uw_request_init() {
+  uw_context ctx;
+  failure_kind fk;
+
+  uw_global_init();
+
+  ctx = uw_request_new_context();
+
+  if (!ctx)
+    exit(1);
+
+  for (fk = uw_initialize(ctx); fk == UNLIMITED_RETRY; fk = uw_initialize(ctx)) {
+    printf("Unlimited retry during init: %s\n", uw_error_message(ctx));
+    uw_db_rollback(ctx);
+    uw_reset(ctx);
+  }
+
+  if (fk != SUCCESS) {
+    printf("Failed to initialize database!  %s\n", uw_error_message(ctx));
+    uw_db_rollback(ctx);
+    exit(1);
+  }
+
+  uw_free(ctx);
+
+  init_crypto();
+}
+
+void uw_sign(const char *in, char *out) {
+  MHASH td;
+
+  td = mhash_hmac_init(HASH_ALGORITHM, private_key, sizeof(private_key),
+                       mhash_get_hash_pblock(HASH_ALGORITHM));
+  
+  mhash(td, in, strlen(in));
+  if (mhash_hmac_deinit(td, out) < 0)
+    printf("Signing failed");
+}
+
+typedef struct uw_rc {
+  size_t path_copy_size;
+  char *path_copy;
+} *uw_request_context;
+
+uw_request_context uw_new_request_context(void) {
+  uw_request_context r = malloc(sizeof(struct uw_rc));
+  r->path_copy_size = 0;
+  r->path_copy = malloc(0);
+  return r;
+}
+
+void uw_free_request_context(uw_request_context r) {
+  free(r->path_copy);
+  free(r);
+}
+
+request_result uw_request(uw_request_context rc, uw_context ctx, char *request, size_t request_len, int sock) {
+  int retries_left = MAX_RETRIES;
+  char *s;
+  failure_kind fk;
+  int is_post = 0, do_normal_send = 1;
+  char *boundary = NULL;
+  size_t boundary_len;
+  char *cmd, *path, *headers, *inputs, *after_headers;
+
+  if (!(s = strstr(request, "\r\n\r\n"))) {
+    fprintf(stderr, "No end of headers found in request\n");
+    return FAILED;
+  }
+
+  s[2] = 0;
+  after_headers = s + 4;
+
+  if (!(s = strstr(request, "\r\n"))) {
+    fprintf(stderr, "No newline in request\n");
+    return FAILED;
+  }
+
+  *s = 0;
+  headers = s + 2;
+  cmd = s = request;
+
+  if (!strsep(&s, " ")) {
+    fprintf(stderr, "No first space in HTTP command\n");
+    return FAILED;
+  }
+
+  uw_set_headers(ctx, headers);
+
+  if (!strcmp(cmd, "POST")) {
+    char *clen_s = uw_Basis_requestHeader(ctx, "Content-length");
+    if (!clen_s) {
+      fprintf(stderr, "No Content-length with POST\n");
+      return FAILED;
+    }
+    int clen = atoi(clen_s);
+    if (clen < 0) {
+      fprintf(stderr, "Negative Content-length with POST\n");
+      return FAILED;
+    }
+
+    if (request + request_len - after_headers < clen) {
+      fprintf(stderr, "Request doesn't contain all POST data (according to Content-Length)\n");
+      return FAILED;
+    }
+
+    is_post = 1;
+
+    clen_s = uw_Basis_requestHeader(ctx, "Content-type");
+    if (clen_s && !strncasecmp(clen_s, "multipart/form-data", 19)) {
+      if (strncasecmp(clen_s + 19, "; boundary=", 11)) {
+        fprintf(stderr, "Bad multipart boundary spec");
+        return FAILED;
+      }
+
+      boundary = clen_s + 28;
+      boundary[0] = '-';
+      boundary[1] = '-';
+      boundary_len = strlen(boundary);
+    }
+  } else if (strcmp(cmd, "GET")) {
+    fprintf(stderr, "Not ready for non-GET/POST command: %s\n", cmd);
+    return FAILED;
+  }
+
+  path = s;
+  if (!strsep(&s, " ")) {
+    fprintf(stderr, "No second space in HTTP command\n");
+    return FAILED;
+  }
+
+  if (!strcmp(path, "/.msgs")) {
+    char *id = uw_Basis_requestHeader(ctx, "UrWeb-Client");
+    char *pass = uw_Basis_requestHeader(ctx, "UrWeb-Pass");
+
+    if (sock < 0) {
+      fprintf(stderr, ".msgs requested, but not socket supplied\n");
+      return FAILED;
+    }
+
+    if (id && pass) {
+      unsigned idn = atoi(id);
+      uw_client_connect(idn, atoi(pass), sock);
+      fprintf(stderr, "Processed request for messages by client %u\n\n", idn);
+      return KEEP_OPEN;
+    }
+    else {
+      fprintf(stderr, "Missing fields in .msgs request: %s, %s\n\n", id, pass);
+      return FAILED;
+    }
+  }
+
+  if (boundary) {
+    char *part = after_headers, *after_sub_headers, *header, *after_header;
+    size_t part_len;
+
+    part = strstr(part, boundary);
+    if (!part) {
+      fprintf(stderr, "Missing first multipart boundary\n");
+      return FAILED;
+    }
+    part += boundary_len;
+
+    while (1) {
+      char *name = NULL, *filename = NULL, *type = NULL;
+
+      if (part[0] == '-' && part[1] == '-')
+        break;
+
+      if (*part != '\r') {
+        fprintf(stderr, "No \\r after multipart boundary\n");
+        return FAILED;
+      }
+      ++part;
+      if (*part != '\n') {
+        fprintf(stderr, "No \\n after multipart boundary\n");
+        return FAILED;
+      }
+      ++part;
+            
+      if (!(after_sub_headers = strstr(part, "\r\n\r\n"))) {
+        fprintf(stderr, "Missing end of headers after multipart boundary\n");
+        return FAILED;
+      }
+      after_sub_headers[2] = 0;
+      after_sub_headers += 4;
+
+      for (header = part; after_header = strstr(header, "\r\n"); header = after_header + 2) {
+        char *colon, *after_colon;
+
+        *after_header = 0;
+        if (!(colon = strchr(header, ':'))) {
+          fprintf(stderr, "Missing colon in multipart sub-header\n");
+          return FAILED;
+        }
+        *colon++ = 0;
+        if (*colon++ != ' ') {
+          fprintf(stderr, "No space after colon in multipart sub-header\n");
+          return FAILED;
+        }
+        
+        if (!strcasecmp(header, "Content-Disposition")) {
+          if (strncmp(colon, "form-data; ", 11)) {
+            fprintf(stderr, "Multipart data is not \"form-data\"\n");
+            return FAILED;
+          }
+
+          for (colon += 11; after_colon = strchr(colon, '='); colon = after_colon) {
+            char *data;
+            after_colon[0] = 0;
+            if (after_colon[1] != '"') {
+              fprintf(stderr, "Disposition setting is missing initial quote\n");
+              return FAILED;
+            }
+            data = after_colon+2;
+            if (!(after_colon = strchr(data, '"'))) {
+              fprintf(stderr, "Disposition setting is missing final quote\n");
+              return FAILED;
+            }
+            after_colon[0] = 0;
+            ++after_colon;
+            if (after_colon[0] == ';' && after_colon[1] == ' ')
+              after_colon += 2;
+
+            if (!strcasecmp(colon, "name"))
+              name = data;
+            else if (!strcasecmp(colon, "filename"))
+              filename = data;
+          }
+        } else if (!strcasecmp(header, "Content-Type")) {
+          type = colon;
+        }
+      }
+
+      part = memmem(after_sub_headers, request + request_len - after_sub_headers, boundary, boundary_len);
+      if (!part) {
+        fprintf(stderr, "Missing boundary after multipart payload\n");
+        return FAILED;
+      }
+      part[-2] = 0;
+      part_len = part - after_sub_headers - 2;
+      part[0] = 0;
+      part += boundary_len;
+
+      if (filename) {
+        uw_Basis_file f = {filename, type, {part_len, after_sub_headers}};
+
+        if (uw_set_file_input(ctx, name, f)) {
+          fprintf(stderr, "%s\n", uw_error_message(ctx));
+          return FAILED;
+        }
+      } else if (uw_set_input(ctx, name, after_sub_headers)) {
+        fprintf(stderr, "%s\n", uw_error_message(ctx));
+        return FAILED;
+      }
+    }
+  }
+  else {
+    if (is_post)
+      inputs = after_headers;
+    else if (inputs = strchr(path, '?'))
+      *inputs++ = 0;
+
+    if (inputs) {
+      char *name, *value;
+
+      while (*inputs) {
+        name = inputs;
+        if (inputs = strchr(inputs, '&'))
+          *inputs++ = 0;
+        else
+          inputs = strchr(name, 0);
+
+        if (value = strchr(name, '=')) {
+          *value++ = 0;
+          if (uw_set_input(ctx, name, value)) {
+            fprintf(stderr, "%s\n", uw_error_message(ctx));
+            return FAILED;
+          }
+        }
+        else if (uw_set_input(ctx, name, "")) {
+          fprintf(stderr, "%s\n", uw_error_message(ctx));
+          return FAILED;
+        }
+      }
+    }
+  }
+
+  printf("Serving URI %s....\n", path);
+
+  while (1) {
+    size_t path_len = strlen(path);
+
+    uw_write_header(ctx, "HTTP/1.1 200 OK\r\n");
+
+    if (path_len + 1 > rc->path_copy_size) {
+      rc->path_copy_size = path_len + 1;
+      rc->path_copy = realloc(rc->path_copy, rc->path_copy_size);
+    }
+    strcpy(rc->path_copy, path);
+    fk = uw_begin(ctx, rc->path_copy);
+    if (fk == SUCCESS || fk == RETURN_BLOB) {
+      uw_commit(ctx);
+      return SERVED;
+    } else if (fk == BOUNDED_RETRY) {
+      if (retries_left) {
+        printf("Error triggers bounded retry: %s\n", uw_error_message(ctx));
+        --retries_left;
+      }
+      else {
+        printf("Fatal error (out of retries): %s\n", uw_error_message(ctx));
+
+        try_rollback(ctx);
+
+        uw_reset_keep_error_message(ctx);
+        uw_write_header(ctx, "HTTP/1.1 500 Internal Server Error\n\r");
+        uw_write_header(ctx, "Content-type: text/plain\r\n");
+        uw_write(ctx, "Fatal error (out of retries): ");
+        uw_write(ctx, uw_error_message(ctx));
+        uw_write(ctx, "\n");
+
+        return FAILED;
+      }
+    } else if (fk == UNLIMITED_RETRY)
+      printf("Error triggers unlimited retry: %s\n", uw_error_message(ctx));
+    else if (fk == FATAL) {
+      printf("Fatal error: %s\n", uw_error_message(ctx));
+
+      try_rollback(ctx);
+
+      uw_reset_keep_error_message(ctx);
+      uw_write_header(ctx, "HTTP/1.1 500 Internal Server Error\r\n");
+      uw_write_header(ctx, "Content-type: text/html\r\n");
+      uw_write(ctx, "<html><head><title>Fatal Error</title></head><body>");
+      uw_write(ctx, "Fatal error: ");
+      uw_write(ctx, uw_error_message(ctx));
+      uw_write(ctx, "\n</body></html>");
+
+      return FAILED;
+    } else {
+      printf("Unknown uw_handle return code!\n");
+
+      try_rollback(ctx);
+
+      uw_reset_keep_request(ctx);
+      uw_write_header(ctx, "HTTP/1.1 500 Internal Server Error\n\r");
+      uw_write_header(ctx, "Content-type: text/plain\r\n");
+      uw_write(ctx, "Unknown uw_handle return code!\n");
+
+      return FAILED;
+    }
+
+    if (try_rollback(ctx))
+      return FAILED;
+
+    uw_reset_keep_request(ctx);
+  }
+}
+
+void *client_pruner(void *data) {
+  uw_context ctx = uw_request_new_context();
+
+  if (!ctx)
+    exit(1);
+
+  while (1) {
+    uw_prune_clients(ctx);
+    sleep(5);
+  }
+}