yasukata
commented
2 months ago Thank you for your message.
can I get the code of the Simple HTTP server mentioned in the paper?
This is the code that I used.
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <inttypes.h>
#include <sys/poll.h>
#include <sys/epoll.h>
#include <sys/ioctl.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <netinet/tcp.h>
#include <arpa/inet.h>
#include <errno.h>
#include <signal.h>
#define SESSION_MAX 1024
#define D(fmt, ...) \
printf("[%s]: "fmt"\n", __func__, ##__VA_ARGS__)
static int do_abort = 0;
static void
sigint_h(int sig)
{
(void)sig; /* UNUSED */
do_abort = 1;
D("Stop process");
signal(SIGINT, SIG_DFL);
}
static void
usage(void)
{
fprintf(stderr,
"usage: this_program -p [port] -l [msglen]\n");
exit(1);
}
ssize_t
generate_httphdr(ssize_t content_length, char *buf, char *content)
{
char *p = buf;
/* From nginx */
static char *lines[5] = {"HTTP/1.1 200 OK\r\n",
"Content-Length: ",
"Connection: keep-alive\r\n\r\n"};
ssize_t l;
memcpy(p, lines[0], strlen(lines[0]));
p += strlen(lines[0]);
memcpy(p, lines[1], strlen(lines[1]));
p += strlen(lines[1]);
l = sprintf(p, "%lu\r\n", content_length);
p += l;
memcpy(p, lines[2], strlen(lines[2]));
p += strlen(lines[2]);
if (content == NULL)
memset(p, 'A', content_length);
else
memcpy(p, content, content_length);
p += content_length;
return p - buf;
}
int accept_session(int fd, int epfd)
{
struct epoll_event ev;
struct sockaddr_in caddr_in;
socklen_t addrlen;
int newfd;
while ((newfd = accept(fd, (struct sockaddr *)&caddr_in, &addrlen)) != -1) {
memset(&ev, 0, sizeof(ev));
ev.events = POLLIN;
ev.data.fd = newfd;
epoll_ctl(epfd, EPOLL_CTL_ADD, newfd, &ev);
}
return 0;
}
int pkt_processing(int fd, ssize_t msglen)
{
ssize_t len;
static char buf[70000];
len = read(fd, buf, sizeof(buf));
if (len == 0) {
close(fd);
return 0;
} else if (len < 0) {
D("read fail, fd %d, ret %ld", fd, len);
return -1;
}
if (strncmp(buf, "GET ", strlen("GET ")) == 0) {
len = generate_httphdr(msglen, buf, NULL);
}
if (write(fd, buf, len) < 0) {
perror("write");
return -1;
}
return 0;
}
int
main(int argc, char **argv)
{
int ch;
int tcp_sockfd;
struct sockaddr_in saddr_in;
int yes;
int port = 0;
int val = 1;
int epfd;
struct epoll_event ev;
struct epoll_event evts[SESSION_MAX];
ssize_t msglen = 1;
fprintf(stderr, "%s built %s %s\n",
argv[0], __DATE__, __TIME__);
while ((ch = getopt(argc, argv, "p:l:")) != -1) {
switch (ch) {
default:
D("bad option %c %s", ch, optarg);
usage();
break;
case 'p': /* server port */
if (port == 0)
port = atoi(optarg);
else
D("%s ignored, already have 1 interface",
optarg);
break;
case 'l':
msglen = atoi(optarg);
break;
}
}
argc -= optind;
argv += optind;
if (port == 0) {
D("missing port number");
usage();
return -1;
}
epfd = epoll_create1(EPOLL_CLOEXEC);
if (epfd == -1) {
D("epoll create failed");
goto close;
}
D("Linux TCP stack, msglen (%lu)", msglen);
tcp_sockfd = socket(PF_INET, SOCK_STREAM, IPPROTO_TCP);
if (tcp_sockfd < 0) {
perror("socket");
goto close_fra;
}
yes = 1;
if (setsockopt(tcp_sockfd, SOL_SOCKET, SO_REUSEADDR, &yes, sizeof(yes)) < 0) {
perror("setsockopt");
goto close_sock;
}
yes = 1;
if (setsockopt(tcp_sockfd, SOL_TCP, TCP_NODELAY, &yes, sizeof(yes)) < 0) {
perror("setsockopt");
goto close_sock;
}
if (ioctl(tcp_sockfd, FIONBIO, &val) < 0) {
perror("ioctl");
goto close_sock;
}
memset(&saddr_in, 0, sizeof(struct sockaddr_in));
saddr_in.sin_family = AF_INET;
saddr_in.sin_addr.s_addr = htonl(INADDR_ANY);
saddr_in.sin_port = htons(port);
if (bind(tcp_sockfd, (struct sockaddr *)&saddr_in, sizeof(saddr_in)) < 0) {
perror("bind");
goto close_sock;
}
if (listen(tcp_sockfd, SOMAXCONN) != 0) {
perror("listen");
goto close_sock;
}
memset(&ev, 0, sizeof(ev));
ev.events = POLLIN;
ev.data.fd = tcp_sockfd;
epoll_ctl(epfd, EPOLL_CTL_ADD, tcp_sockfd, &ev);
signal(SIGINT, sigint_h);
while (!do_abort) {
int i, nfd;
nfd = epoll_wait(epfd, evts, SESSION_MAX, -1); // If we specify -1 here, epoll blocks
for (i = 0; i < nfd; i++) {
if (evts[i].data.fd == tcp_sockfd) {
if (accept_session(tcp_sockfd, epfd) < 0)
goto close_sock;
} else
pkt_processing(evts[i].data.fd, msglen);
}
}
close_sock:
close(tcp_sockfd);
close_fra:
close(epfd);
close:
return (0);
}I hope this works in your environment.
Thank you very much for your interest.
98hq
Hello, can I get the code of the Simple HTTP server mentioned in the paper? Because I encountered some problems in the process of reproducing the paper. SUD can encounter problems when hooking multi-threaded programs, possibly because signals are modified when creating threads. I see that you handle this in your code, but it triggers a crash when I use it, so I'd like to get the procedure you evaluated to fix the problem.