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#include "ImageProxy.h"
#include <curl/curl.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#define MAX_IMAGE_SIZE (10 * 1024 * 1024)
typedef struct {
char *data;
size_t size;
size_t capacity;
} MemoryBuffer;
static int is_allowed_domain(const char *url) {
const char *protocol = strstr(url, "://");
if (!protocol) {
protocol = url;
} else {
protocol += 3;
}
const char *path = strchr(protocol, '/');
size_t host_len = path ? (size_t)(path - protocol) : strlen(protocol);
char host[256] = {0};
if (host_len >= sizeof(host)) {
host_len = sizeof(host) - 1;
}
strncpy(host, protocol, host_len);
const char *allowed_domains[] = {
"mm.bing.net",
"th.bing.com",
NULL
};
for (int i = 0; allowed_domains[i] != NULL; i++) {
size_t domain_len = strlen(allowed_domains[i]);
size_t host_str_len = strlen(host);
if (host_str_len >= domain_len) {
const char *suffix = host + host_str_len - domain_len;
if (strcmp(suffix, allowed_domains[i]) == 0) {
return 1;
}
}
}
return 0;
}
static size_t write_callback(void *contents, size_t size, size_t nmemb,
void *userp) {
size_t realsize = size * nmemb;
MemoryBuffer *buf = (MemoryBuffer *)userp;
if (buf->size + realsize > MAX_IMAGE_SIZE) {
return 0;
}
if (buf->size + realsize > buf->capacity) {
size_t new_capacity = buf->capacity * 2;
if (new_capacity < buf->size + realsize) {
new_capacity = buf->size + realsize;
}
char *new_data = realloc(buf->data, new_capacity);
if (!new_data) return 0;
buf->data = new_data;
buf->capacity = new_capacity;
}
memcpy(buf->data + buf->size, contents, realsize);
buf->size += realsize;
return realsize;
}
int image_proxy_handler(UrlParams *params) {
const char *url = NULL;
for (int i = 0; i < params->count; i++) {
if (strcmp(params->params[i].key, "url") == 0) {
url = params->params[i].value;
break;
}
}
if (!url || strlen(url) == 0) {
send_response("Missing 'url' parameter");
return 0;
}
if (!is_allowed_domain(url)) {
send_response("Domain not allowed");
return 0;
}
CURL *curl = curl_easy_init();
if (!curl) {
send_response("Failed to initialize curl");
return 0;
}
MemoryBuffer buf = {
.data = malloc(8192),
.size = 0,
.capacity = 8192
};
if (!buf.data) {
curl_easy_cleanup(curl);
send_response("Memory allocation failed");
return 0;
}
curl_easy_setopt(curl, CURLOPT_URL, url);
curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, write_callback);
curl_easy_setopt(curl, CURLOPT_WRITEDATA, &buf);
curl_easy_setopt(curl, CURLOPT_FOLLOWLOCATION, 1L);
curl_easy_setopt(curl, CURLOPT_TIMEOUT, 10L);
CURLcode res = curl_easy_perform(curl);
long response_code;
curl_easy_getinfo(curl, CURLINFO_RESPONSE_CODE, &response_code);
char *content_type_ptr = NULL;
curl_easy_getinfo(curl, CURLINFO_CONTENT_TYPE, &content_type_ptr);
char content_type[64] = {0};
if (content_type_ptr) {
strncpy(content_type, content_type_ptr, sizeof(content_type) - 1);
}
curl_easy_cleanup(curl);
if (res != CURLE_OK || response_code != 200) {
free(buf.data);
send_response("Failed to fetch image");
return 0;
}
const char *mime_type = strlen(content_type) > 0 ? content_type : "image/jpeg";
serve_data(buf.data, buf.size, mime_type);
free(buf.data);
return 0;
}
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