+/*
+ * Copyright © 2018 Keith Packard <keithp@keithp.com>
+ *
+ * This program 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 2 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.
+ */
+
+#include <jansson.h>
+#include <stdlib.h>
+#include <stdarg.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <unistd.h>
+#include <string.h>
+#include <fcntl.h>
+#include <errno.h>
+#include <limits.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <sys/socket.h>
+#include <netinet/ip.h>
+
+#define ALTOS_MAP_PORT 16717
+
+#define MISSING 0x7fffffff
+
+#define ALTOS_MAP_PROTOCOL_VERSION "1.0.0"
+
+static char *
+reason_string(int code)
+{
+ switch (code) {
+ case 200:
+ return "OK";
+ case 400:
+ return "Bad Request";
+ case 403:
+ return "Forbidden";
+ case 404:
+ return "Not Found";
+ case 408:
+ return "Request Timeout";
+ default:
+ return "Failure";
+ }
+}
+
+static void
+write_status(int status)
+{
+ printf("Status: %d %s\n", status, reason_string(status));
+}
+
+static void
+write_type(char * type)
+{
+ printf("Content-Type: %s\n", type);
+}
+
+static void
+fail(int status, char *format, ...)
+{
+ va_list ap;
+
+ write_status(status);
+ write_type("text/html");
+ printf("\n");
+ printf("<html>\n");
+ printf("<head><title>Map Fetch Failure</title></head>\n");
+ printf("<body>\n");
+ va_start(ap, format);
+ vprintf(format, ap);
+ va_end(ap);
+ printf("</body>\n");
+ printf("</html>\n");
+ exit(1);
+}
+
+static char *
+getenv_copy(const char *name)
+{
+ const char *value = getenv(name);
+
+ if (!value)
+ return NULL;
+
+ return strdup(value);
+}
+
+static double
+parse_double(char *string)
+{
+ char *end;
+ double value;
+
+ value = strtod(string, &end);
+ if (*end)
+ fail(400, "Invalid double %s", string);
+ return value;
+}
+
+static int
+parse_int(char *string)
+{
+ char *end;
+ long int value;
+
+ value = strtol(string, &end, 10);
+ if (*end)
+ fail(400, "Invalid int %s", string);
+ if (value < INT_MIN || INT_MAX < value)
+ fail(400, "Int value out of range %ld", value);
+ return (int) value;
+}
+
+
+static int
+connect_service(void)
+{
+ struct sockaddr_in altos_map_addr = {
+ .sin_family = AF_INET,
+ .sin_port = htons(ALTOS_MAP_PORT),
+ .sin_addr = {
+ .s_addr = htonl(INADDR_LOOPBACK),
+ },
+ };
+
+ int s = socket(AF_INET, SOCK_STREAM, 0);
+
+ if (s < 0)
+ return -1;
+
+ if (connect (s, (const struct sockaddr *) &altos_map_addr, sizeof (altos_map_addr)) < 0) {
+ close (s);
+ return -1;
+ }
+
+ return s;
+}
+
+int main(int argc, char **argv)
+{
+
+ char *query_string = getenv_copy("QUERY_STRING");
+
+ if (query_string == NULL)
+ fail(400, "%s", "Missing query string");
+
+ char *remote_addr = getenv_copy("REMOTE_ADDR");
+
+ if (remote_addr == NULL)
+ fail(400, "%s", "Missing remote address");
+
+ double lon = MISSING;
+ double lat = MISSING;
+ int zoom = MISSING;
+ char *version = NULL;
+
+ char *query, *query_save = NULL;
+ char *query_start = query_string;
+
+ while ((query = strtok_r(query_start, "&", &query_save)) != NULL) {
+ query_start = NULL;
+
+ char *token, *token_save = NULL;
+ char *token_start = query;
+
+ char *name = NULL;
+ char *value = NULL;
+
+ while ((token = strtok_r(token_start, "=", &token_save)) != NULL) {
+ token_start = NULL;
+ if (name == NULL)
+ name = token;
+ else if (value == NULL)
+ value = token;
+ else
+ break;
+ }
+
+ if (name && value) {
+ if (!strcmp(name, "lon"))
+ lon = parse_double(value);
+ else if (!strcmp(name, "lat"))
+ lat = parse_double(value);
+ else if (!strcmp(name, "zoom"))
+ zoom = parse_int(value);
+ else if (!strcmp(name, "version"))
+ version = value;
+ else
+ fail(400, "Extra query param \"%s\"", query);
+ }
+ }
+
+ if (version != NULL) {
+ printf("Content-Type: text/plain\n");
+ printf("\n");
+ printf("%s\n", ALTOS_MAP_PROTOCOL_VERSION);
+ return 0;
+ }
+ if (lon == MISSING)
+ fail(400, "Missing longitude");
+ if (lat == MISSING)
+ fail(400, "Missing latitude");
+ if (zoom == MISSING)
+ fail(400, "Missing zoom");
+
+ int s = -1;
+ int tries = 0;
+
+ while (tries < 10 && s < 0) {
+ s = connect_service();
+ if (s < 0) {
+ usleep(100 * 1000);
+ tries++;
+ }
+ }
+
+ if (s < 0)
+ fail(408, "Cannot connect AltOS map daemon");
+
+ json_t *request = json_pack("{s:f s:f s:i s:s}", "lat", lat, "lon", lon, "zoom", zoom, "remote_addr", remote_addr);
+
+ if (request == NULL)
+ fail(400, "Cannot create JSON request");
+
+ if (json_dumpfd(request, s, 0) < 0)
+ fail(400, "Cannot write JSON request");
+
+ json_error_t error;
+ json_t *reply = json_loadfd(s, 0, &error);
+
+ if (!reply)
+ fail(400, "Cannot read JSON reply");
+
+ int status;
+
+ if (json_unpack(reply, "{s:i}", "status", &status) < 0)
+ fail(400, "No status returned");
+
+ if (status != 200)
+ fail(status, "Bad cache status");
+
+ char *filename, *content_type;
+
+ if (json_unpack(reply, "{s:s s:s}", "filename", &filename, "content_type", &content_type) < 0)
+ fail(400, "JSON reply parse failure");
+
+ int fd = open(filename, O_RDONLY);
+
+ if (fd < 0)
+ fail(400, "%s: %s", filename, strerror(errno));
+
+ struct stat statb;
+
+ if (fstat(fd, &statb) < 0)
+ fail(400, "%s: %s", filename, strerror(errno));
+
+ printf("Content-Type: %s\n", content_type);
+ printf("Content-Length: %lu\n", (unsigned long) statb.st_size);
+ printf("\n");
+ fflush(stdout);
+
+ char buf[4096];
+ ssize_t bytes_read;
+
+ while ((bytes_read = read(fd, buf, sizeof (buf))) > 0) {
+ ssize_t total_write = 0;
+ while (total_write < bytes_read) {
+ ssize_t bytes_write = write(1, buf + total_write, bytes_read - total_write);
+ if (bytes_write <= 0)
+ return 1;
+ total_write += bytes_write;
+ }
+ }
+ if (bytes_read < 0)
+ return 1;
+ return 0;
+}