Files
sesimos/src/rev_proxy.c
2021-01-07 22:35:49 +01:00

267 lines
10 KiB
C

/**
* Necronda Web Server
* Reverse proxy
* src/rev_proxy.c
* Lorenz Stechauner, 2021-01-07
*/
#include "rev_proxy.h"
sock rev_proxy;
char *rev_proxy_host = NULL;
struct timeval server_timeout = {.tv_sec = SERVER_TIMEOUT, .tv_usec = 0};
int rev_proxy_init(http_req *req, http_res *res, host_config *conf, sock *client, http_status *custom_status,
char * err_msg) {
char buffer[CHUNK_SIZE];
long ret;
int new = 0;
int retry = 0;
if (rev_proxy.socket != 0 && rev_proxy_host == conf->name) {
goto rev_proxy;
} else if (rev_proxy.socket != 0) {
sock_close(&rev_proxy);
}
retry:
retry = 0;
new = 1;
rev_proxy.socket = socket(AF_INET6, SOCK_STREAM, 0);
if (rev_proxy.socket < 0) {
print(ERR_STR "Unable to create socket: %s" CLR_STR, strerror(errno));
res->status = http_get_status(500);
return -1;
}
server_timeout.tv_sec = SERVER_TIMEOUT;
server_timeout.tv_usec = 0;
if (setsockopt(client->socket, SOL_SOCKET, SO_RCVTIMEO, &server_timeout, sizeof(server_timeout)) < 0)
goto rev_proxy_timeout_err;
if (setsockopt(client->socket, SOL_SOCKET, SO_SNDTIMEO, &server_timeout, sizeof(server_timeout)) < 0) {
rev_proxy_timeout_err:
res->status = http_get_status(502);
print(ERR_STR "Unable to set timeout for socket: %s" CLR_STR, strerror(errno));
sprintf(err_msg, "Unable to set timeout for socket: %s", strerror(errno));
goto proxy_err;
}
struct hostent *host_ent = gethostbyname(conf->rev_proxy.hostname);
if (host_ent == NULL) {
res->status = http_get_status(502);
print(ERR_STR "Unable to connect to server: Name or service not known" CLR_STR);
sprintf(err_msg, "Unable to connect to server: Name or service not known.");
goto proxy_err;
}
struct sockaddr_in6 address = {.sin6_family = AF_INET6, .sin6_port = htons(conf->rev_proxy.port)};
if (host_ent->h_addrtype == AF_INET6) {
memcpy(&address.sin6_addr, host_ent->h_addr_list[0], host_ent->h_length);
} else if (host_ent->h_addrtype == AF_INET) {
unsigned char addr[16] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0xFF, 0xFF, 0, 0, 0, 0};
memcpy(addr + 12, host_ent->h_addr_list[0], host_ent->h_length);
memcpy(&address.sin6_addr, addr, 16);
}
if (connect(rev_proxy.socket, (struct sockaddr *) &address, sizeof(address)) < 0) {
res->status = http_get_status(502);
print(ERR_STR "Unable to connect to server: %s" CLR_STR, strerror(errno));
sprintf(err_msg, "Unable to connect to server: %s.", strerror(errno));
goto proxy_err;
}
if (conf->rev_proxy.enc) {
rev_proxy.ssl = SSL_new(rev_proxy.ctx);
SSL_set_fd(rev_proxy.ssl, rev_proxy.socket);
SSL_set_connect_state(rev_proxy.ssl);
ret = SSL_do_handshake(rev_proxy.ssl);
rev_proxy._last_ret = ret;
rev_proxy._errno = errno;
rev_proxy._ssl_error = ERR_get_error();
rev_proxy.enc = 1;
if (ret < 0) {
res->status = http_get_status(502);
print(ERR_STR "Unable to perform handshake: %s" CLR_STR, sock_strerror(&rev_proxy));
sprintf(err_msg, "Unable to perform handshake: %s.", sock_strerror(&rev_proxy));
goto proxy_err;
}
}
rev_proxy_host = conf->name;
inet_ntop(address.sin6_family, (void *) &address.sin6_addr, buffer, sizeof(buffer));
print(BLUE_STR "Established new connection with " BLD_STR "[%s]:%i" CLR_STR, buffer, conf->rev_proxy.port);
rev_proxy:
http_remove_header_field(&req->hdr, "Connection", HTTP_REMOVE_ALL);
http_add_header_field(&req->hdr, "Connection", "keep-alive");
ret = http_send_request(&rev_proxy, req);
if (ret < 0) {
res->status = http_get_status(502);
print(ERR_STR "Unable to send request to server: %s" CLR_STR, sock_strerror(&rev_proxy));
sprintf(err_msg, "Unable to send request to server: %s.", sock_strerror(&rev_proxy));
retry = !new;
goto proxy_err;
}
char *content_length = http_get_header_field(&req->hdr, "Content-Length");
if (content_length != NULL) {
unsigned long content_len = strtoul(content_length, NULL, 10);
if (client->buf_len - client->buf_off > 0) {
unsigned long len = client->buf_len - client->buf_off;
if (len > content_len) {
len = content_len;
}
ret = sock_send(&rev_proxy, client->buf, len, 0);
if (ret <= 0) {
res->status = http_get_status(502);
print(ERR_STR "Unable to send request to server: %s" CLR_STR, sock_strerror(&rev_proxy));
sprintf(err_msg, "Unable to send request to server: %s.", sock_strerror(&rev_proxy));
retry = !new;
goto proxy_err;
}
content_len -= len;
}
if (content_len > 0) {
ret = sock_splice(&rev_proxy, client, buffer, sizeof(buffer), content_len);
if (ret <= 0) {
res->status = http_get_status(502);
print(ERR_STR "Unable to send request to server: %s" CLR_STR, sock_strerror(&rev_proxy));
sprintf(err_msg, "Unable to send request to server: %s.", sock_strerror(&rev_proxy));
retry = !new;
goto proxy_err;
}
}
}
ret = sock_recv(&rev_proxy, buffer, sizeof(buffer), MSG_PEEK);
if (ret <= 0) {
res->status = http_get_status(502);
print(ERR_STR "Unable to receive response from server: %s" CLR_STR, sock_strerror(&rev_proxy));
sprintf(err_msg, "Unable to receive response from server: %s.", sock_strerror(&rev_proxy));
retry = !new;
goto proxy_err;
}
char *buf = buffer;
unsigned short header_len = (unsigned short) (strstr(buffer, "\r\n\r\n") - buffer + 4);
if (header_len <= 0) {
res->status = http_get_status(502);
print(ERR_STR "Unable to parse header: End of header not found" CLR_STR);
sprintf(err_msg, "Unable to parser header: End of header not found.");
goto proxy_err;
}
for (int i = 0; i < header_len; i++) {
if ((buf[i] >= 0x00 && buf[i] <= 0x1F && buf[i] != '\r' && buf[i] != '\n') || buf[i] == 0x7F) {
res->status = http_get_status(502);
print(ERR_STR "Unable to parse header: Header contains illegal characters" CLR_STR);
sprintf(err_msg, "Unable to parse header: Header contains illegal characters.");
goto proxy_err;
}
}
char *ptr = buf;
while (header_len != (ptr - buf)) {
char *pos0 = strstr(ptr, "\r\n");
if (pos0 == NULL) {
res->status = http_get_status(502);
print(ERR_STR "Unable to parse header: Invalid header format" CLR_STR);
sprintf(err_msg, "Unable to parse header: Invalid header format.");
goto proxy_err;
}
if (ptr == buf) {
if (strncmp(ptr, "HTTP/", 5) != 0) {
res->status = http_get_status(502);
print(ERR_STR "Unable to parse header: Invalid header format" CLR_STR);
sprintf(err_msg, "Unable to parse header: Invalid header format.");
goto proxy_err;
}
int status_code = (int) strtol(ptr + 9, NULL, 10);
res->status = http_get_status(status_code);
if (res->status == NULL && status_code >= 100 && status_code <= 999) {
custom_status->code = status_code;
strcpy(custom_status->type, "");
strncpy(custom_status->msg, ptr + 13, strchr(ptr, '\r') - ptr - 13);
res->status = custom_status;
} else if (res->status == NULL) {
res->status = http_get_status(502);
print(ERR_STR "Unable to parse header: Invalid or unknown status code" CLR_STR);
sprintf(err_msg, "Unable to parse header: Invalid or unknown status code.");
goto proxy_err;
}
} else {
ret = http_parse_header_field(&res->hdr, ptr, pos0);
if (ret != 0) {
res->status = http_get_status(502);
print(ERR_STR "Unable to parse header" CLR_STR);
sprintf(err_msg, "Unable to parse header.");
goto proxy_err;
}
}
if (pos0[2] == '\r' && pos0[3] == '\n') {
break;
}
ptr = pos0 + 2;
}
sock_recv(&rev_proxy, buffer, header_len, 0);
return 0;
proxy_err:
print(BLUE_STR "Closing proxy connection" CLR_STR);
sock_close(&rev_proxy);
if (retry) {
goto retry;
}
return -1;
}
int rev_proxy_send(sock *client, int chunked, unsigned long len_to_send) {
long ret;
char buffer[CHUNK_SIZE];
long len, snd_len;
do {
if (chunked) {
ret = sock_recv(&rev_proxy, buffer, 16, MSG_PEEK);
if (ret <= 0) {
print("Unable to receive: %s", sock_strerror(&rev_proxy));
break;
}
len_to_send = strtol(buffer, NULL, 16);
char *pos = strstr(buffer, "\r\n");
len = pos - buffer + 2;
ret = sock_send(client, buffer, len, 0);
sock_recv(&rev_proxy, buffer, len, 0);
if (ret <= 0) break;
}
snd_len = 0;
while (snd_len < len_to_send) {
len = sock_recv(&rev_proxy, buffer, CHUNK_SIZE < (len_to_send - snd_len) ? CHUNK_SIZE : len_to_send - snd_len, 0);
ret = sock_send(client, buffer, len, 0);
if (ret <= 0) {
print(ERR_STR "Unable to send: %s" CLR_STR, sock_strerror(client));
break;
}
snd_len += ret;
}
if (ret <= 0) break;
if (chunked) {
sock_recv(&rev_proxy, buffer, 2, 0);
ret = sock_send(client, "\r\n", 2, 0);
if (ret <= 0) {
print(ERR_STR "Unable to send: %s" CLR_STR, sock_strerror(client));
break;
}
}
} while (chunked && len_to_send > 0);
return 0;
}