Download Client Redirect Querry

Question

Hi, 
 
 I am using download_client to get a bigger file (100KB) to my memory via LTE-M. The Files are located in a bucket and I use a shortURL to get the signedDownload URL. If I use this short URL in Download Client I get the Error "http/1.1 301 moved permanently". This seems to be correct, the URL is initialy ofcourse a redirect. But how can I handle this in my code? I couldnt find a way to read the header files with download client nor do I see any option for redirect hops or something like this. Is there even a solution? Or is it the limits of the low level integration? 
 Thanks for helping and best regards

daniel

danielboe · Answer

I solved the Redirect now manually via socket. I read the complete http response and get my URL. If anybody else ever needs this here is my function: #include char *redirectHttp(const char *endpoint, const char *path) { int fd = 0; int err = 0; int bytes; char send_packet[200]; char recv_buf[1024] = {}; struct addrinfo *res; struct addrinfo hints = { .ai_family = AF_INET, .ai_socktype = SOCK_STREAM, }; err = getaddrinfo(endpoint, "80", &hints, &res); if (err) { LOG_ERR("[SOCKET] getaddrinfo err %d", errno); return 0; } ((struct sockaddr_in *)res->ai_addr)->sin_port = htons(80); fd = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP); // Set socket to tcp without tls if (fd == -1) { LOG_ERR("[SOCKET] failed to open"); return 0; } char ipv4_addr[NET_IPV4_ADDR_LEN]; inet_ntop(AF_INET, &((struct sockaddr_in *)res->ai_addr)->sin_port, ipv4_addr, sizeof(ipv4_addr)); LOG_INF("[SOCKET] Connect to Addr IP: %s", ipv4_addr); err = connect(fd, res->ai_addr, sizeof(struct sockaddr_in)); if (err) { LOG_ERR("[SOCKET] connect() err: %d", errno); return 0; } sprintf(send_packet, "GET %s HTTP/1.1 " "Host: %s " "Accept: txt/plain ", path, endpoint); bytes = send(fd, &send_packet, strlen(send_packet), 0); LOG_INF("[SOCKET] Sent %d bytes", bytes); bytes = blocking_recv(fd, recv_buf, sizeof(recv_buf), 0); LOG_INF("[SOCKET] Received %d bytes", bytes); const char *location_header = "Location: "; const char *start = strstr(recv_buf, location_header); if (start) { start += strlen(location_header); const char *end = strstr(start, " "); if (!end) { end = start + strlen(start); // End of string if no CRLF } size_t length = end - start; if (length < 1024) { char *url = (char *)malloc(length + 1); // Allocate memory for the URL strncpy(url, start, length); url[length] = '\0'; // Null-terminate the string return url; } else { LOG_ERR("[SOCKET] URL is too long to fit in the buffer"); return 0; } } else { LOG_ERR("[SOCKET] Location header not found in the response"); } return 0; } Example Usage: const char *endpoint = "ul1.epaperframe.de"; const char *path = "/tjoLta9.dl"; char *url = redirectHttp(endpoint, path); printf("Redirected URL: %s ", url); free(url); // Free the allocated memory This ticket is solved for me now.