WIP rewrite socks5 file (broken)

This commit is contained in:
Quentin Dufour 2019-03-22 17:14:35 +01:00
parent f5c4669b7c
commit a2bf7ddec1
6 changed files with 198 additions and 61 deletions

View file

@ -77,6 +77,9 @@ void evt_core_mv_fd(struct evt_core_ctx* ctx, struct evt_core_fdinfo* fdinfo, st
// 3. Update new category // 3. Update new category
g_array_append_val (fdinfo->cat->socklist, fdinfo); g_array_append_val (fdinfo->cat->socklist, fdinfo);
// 4. Update epoll flags
update_fd_epoll (ctx->epollfd, fdinfo->fd, fdinfo->cat->flags);
} }
void evt_core_mv_fd2(struct evt_core_ctx* ctx, struct evt_core_fdinfo* fdinfo, char* to_cat) { void evt_core_mv_fd2(struct evt_core_ctx* ctx, struct evt_core_fdinfo* fdinfo, char* to_cat) {
@ -88,7 +91,7 @@ void evt_core_mv_fd2(struct evt_core_ctx* ctx, struct evt_core_fdinfo* fdinfo, c
evt_core_mv_fd (ctx, fdinfo, cat); evt_core_mv_fd (ctx, fdinfo, cat);
} }
void evt_core_add_fd(struct evt_core_ctx* ctx, struct evt_core_fdinfo* user_data) { struct evt_core_fdinfo* evt_core_add_fd(struct evt_core_ctx* ctx, struct evt_core_fdinfo* user_data) {
// 1. Fetch fd category // 1. Fetch fd category
struct evt_core_cat* cat = g_hash_table_lookup(ctx->catlist, user_data->cat->name); struct evt_core_cat* cat = g_hash_table_lookup(ctx->catlist, user_data->cat->name);
if (cat == NULL) { if (cat == NULL) {
@ -123,6 +126,8 @@ void evt_core_add_fd(struct evt_core_ctx* ctx, struct evt_core_fdinfo* user_data
// 5. Add file descriptor to epoll // 5. Add file descriptor to epoll
add_fd_to_epoll(ctx->epollfd, user_data->fd, cat->flags); add_fd_to_epoll(ctx->epollfd, user_data->fd, cat->flags);
printf("Added fd=%d with url=%s in cat=%s\n", fdinfo->fd, fdinfo->url, fdinfo->cat->name); printf("Added fd=%d with url=%s in cat=%s\n", fdinfo->fd, fdinfo->url, fdinfo->cat->name);
return fdinfo;
} }
struct evt_core_cat* evt_core_rm_fd(struct evt_core_ctx* ctx, int fd) { struct evt_core_cat* evt_core_rm_fd(struct evt_core_ctx* ctx, int fd) {

View file

@ -47,7 +47,7 @@ void evt_core_init(struct evt_core_ctx* ctx);
void evt_core_add_cat(struct evt_core_ctx* ctx, struct evt_core_cat* cat); void evt_core_add_cat(struct evt_core_ctx* ctx, struct evt_core_cat* cat);
void evt_core_mv_fd(struct evt_core_ctx* ctx, struct evt_core_fdinfo* fdinfo, struct evt_core_cat* to_cat); void evt_core_mv_fd(struct evt_core_ctx* ctx, struct evt_core_fdinfo* fdinfo, struct evt_core_cat* to_cat);
void evt_core_mv_fd2(struct evt_core_ctx* ctx, struct evt_core_fdinfo* fdinfo, char* to_cat); void evt_core_mv_fd2(struct evt_core_ctx* ctx, struct evt_core_fdinfo* fdinfo, char* to_cat);
void evt_core_add_fd(struct evt_core_ctx* ctx, struct evt_core_fdinfo* user_data); struct evt_core_fdinfo* evt_core_add_fd(struct evt_core_ctx* ctx, struct evt_core_fdinfo* user_data);
struct evt_core_cat* evt_core_rm_fd(struct evt_core_ctx* ctx, int fd); struct evt_core_cat* evt_core_rm_fd(struct evt_core_ctx* ctx, int fd);
void evt_core_free(struct evt_core_ctx* ctx); void evt_core_free(struct evt_core_ctx* ctx);
void evt_core_loop(struct evt_core_ctx* ctx); void evt_core_loop(struct evt_core_ctx* ctx);

View file

@ -165,3 +165,13 @@ void add_fd_to_epoll(int epollfd, int fd, uint32_t flags) {
exit(EXIT_FAILURE); exit(EXIT_FAILURE);
} }
} }
void update_fd_epoll(int epollfd, int fd, uint32_t flags) {
struct epoll_event current_event = {0};
current_event.events = flags;
current_event.data.fd = fd;
if (epoll_ctl (epollfd, EPOLL_CTL_MOD, fd, &current_event) == -1) {
perror("Failed to update a file descriptor to epoll with epoll_ctl");
exit(EXIT_FAILURE);
}
}

View file

@ -14,5 +14,6 @@ int create_tcp_server(char* host, char* service);
int create_udp_server(char* host, char* service); int create_udp_server(char* host, char* service);
int make_socket_non_blocking(int fd); int make_socket_non_blocking(int fd);
void add_fd_to_epoll(int epollfd, int fd, uint32_t flags); void add_fd_to_epoll(int epollfd, int fd, uint32_t flags);
void update_fd_epoll(int epollfd, int fd, uint32_t flags);
int read_entity(int fd, void* entity, int size); int read_entity(int fd, void* entity, int size);
void fill_buffer(size_t* written, char* dest, void *src, size_t n); void fill_buffer(size_t* written, char* dest, void *src, size_t n);

View file

@ -9,11 +9,14 @@ struct socks5_ctx {
uint64_t sh_cursor; uint64_t sh_cursor;
uint64_t cr_cursor; uint64_t cr_cursor;
uint64_t sr_cursor; uint64_t sr_cursor;
uint8_t sr_atyp_read;
char cr_buffer[262]; char cr_buffer[262];
size_t ch_size; size_t ch_size;
size_t cr_size; size_t cr_size;
}; };
int on_socks5_send_handshake(struct evt_core_ctx* ctx, struct evt_core_fdinfo* fdinfo);
void socks5_free_ctx(void* elem) { void socks5_free_ctx(void* elem) {
struct socks5_ctx* ctx = elem; struct socks5_ctx* ctx = elem;
free(ctx); free(ctx);
@ -23,6 +26,7 @@ void create_socks5_dns_client(struct evt_core_ctx* ctx, char* proxy_host, char*
struct evt_core_fdinfo fdinfo; struct evt_core_fdinfo fdinfo;
struct evt_core_cat cat; struct evt_core_cat cat;
struct socks5_ctx* s5ctx; struct socks5_ctx* s5ctx;
struct evt_core_fdinfo* reg_fdinfo;
char url[1024]; char url[1024];
// 0. Compute domain length and enforce an upper bound on its size // 0. Compute domain length and enforce an upper bound on its size
@ -77,7 +81,8 @@ void create_socks5_dns_client(struct evt_core_ctx* ctx, char* proxy_host, char*
fill_buffer(&s5ctx->cr_size, s5ctx->cr_buffer, s5ctx->cr.dst_addr, s5ctx->cr.dst_addr_len*sizeof(char)); fill_buffer(&s5ctx->cr_size, s5ctx->cr_buffer, s5ctx->cr.dst_addr, s5ctx->cr.dst_addr_len*sizeof(char));
fill_buffer(&s5ctx->cr_size, s5ctx->cr_buffer, &s5ctx->cr.port, sizeof(uint16_t)); fill_buffer(&s5ctx->cr_size, s5ctx->cr_buffer, &s5ctx->cr.port, sizeof(uint16_t));
evt_core_add_fd (ctx, &fdinfo); reg_fdinfo = evt_core_add_fd (ctx, &fdinfo);
reg_fdinfo->cat->cb(ctx, reg_fdinfo);
} }
int on_socks5_send_handshake(struct evt_core_ctx* ctx, struct evt_core_fdinfo* fdinfo) { int on_socks5_send_handshake(struct evt_core_ctx* ctx, struct evt_core_fdinfo* fdinfo) {
@ -88,54 +93,190 @@ int on_socks5_send_handshake(struct evt_core_ctx* ctx, struct evt_core_fdinfo* f
if (written < 0) { if (written < 0) {
perror("write failed on tcp socket in socks5"); perror("write failed on tcp socket in socks5");
evt_core_mv_fd2(ctx, fdinfo, "socks5-failed"); evt_core_mv_fd2(ctx, fdinfo, "socks5-failed");
return 0; fdinfo->cat->cb(ctx, fdinfo);
return 1;
} }
s5ctx->ch_cursor += written; s5ctx->ch_cursor += written;
if (s5ctx->ch_cursor < s5ctx->ch_size) return 0; if (s5ctx->ch_cursor < s5ctx->ch_size) return 0;
evt_core_mv_fd2(ctx, fdinfo, "socks5-recv-handshake"); evt_core_mv_fd2(ctx, fdinfo, "socks5-recv-handshake");
return 0; return 1;
} }
int on_socks5_recv_handshake(struct evt_core_ctx* ctx, struct evt_core_fdinfo* fdinfo) { int on_socks5_recv_handshake(struct evt_core_ctx* ctx, struct evt_core_fdinfo* fdinfo) {
struct socks5_ctx* s5ctx = fdinfo->other;
int readn = 0;
if (err == -1) { readn = read(fdinfo->fd, &s5ctx->sh + s5ctx->sh_cursor, sizeof(s5ctx->sh) - s5ctx->sh_cursor);
perror("sock5 handshake failed read"); if (readn == -1 && errno == EAGAIN) return 1;
return -1; if (readn < 0) {
} perror("sock5 handshake failed read");
if (ch.ver != sh.ver || sh.method != ch.methods[0]) { evt_core_mv_fd2(ctx, fdinfo, "socks5-failed");
fprintf(stderr, "Protocol error: client asks for ver=%d, method=%d and server answers with ver=%d, method=%d\n", fdinfo->cat->cb(ctx, fdinfo);
ch.ver, ch.methods[0], sh.ver, sh.method); return 1;
return -1; }
}
printf("[server_handshake] ver=%d, method=%d\n", sh.ver, sh.method); s5ctx->sh_cursor += readn;
return 0; if (s5ctx->sh_cursor < sizeof(s5ctx->sh)) return 0;
if (s5ctx->ch.ver != s5ctx->sh.ver || s5ctx->sh.method != s5ctx->ch.methods[0]) {
fprintf(stderr, "Protocol error: client asks for ver=%d, method=%d and server answers with ver=%d, method=%d\n",
s5ctx->ch.ver, s5ctx->ch.methods[0], s5ctx->sh.ver, s5ctx->sh.method);
evt_core_mv_fd2(ctx, fdinfo, "socks5-failed");
fdinfo->cat->cb(ctx, fdinfo);
return 1;
}
printf("[server_handshake] ver=%d, method=%d\n", s5ctx->sh.ver, s5ctx->sh.method);
evt_core_mv_fd2(ctx, fdinfo, "socks5-send-client-req");
fdinfo->cat->cb(ctx, fdinfo);
return 1;
} }
int socks5_reply(int sock) { int on_socks5_send_client_req(struct evt_core_ctx* ctx, struct evt_core_fdinfo* fdinfo) {
int res; struct socks5_ctx* s5ctx = fdinfo->other;
struct server_reply sr = {0}; int written = 0;
res = read_entity(sock, &sr, sizeof(uint8_t) * 4);
if (res == -1) goto read_error;
switch(sr.atyp) { written = write(fdinfo->fd, s5ctx->cr_buffer + s5ctx->cr_cursor, s5ctx->cr_size - s5ctx->cr_cursor);
case ATYP_IPV4: if (written == -1 && errno == EAGAIN) return 1;
if (read_entity(sock, sr.bind_addr.ipv4, sizeof(uint8_t) * 4) == -1) if (written < 0) {
goto read_error; fprintf(stderr, "socks5 send client request failed\n");
break; evt_core_mv_fd2 (ctx, fdinfo, "socks5-failed");
case ATYP_DOMAINNAME: fdinfo->cat->cb(ctx, fdinfo);
if (read_entity(sock, &sr.bind_addr.dns.len, sizeof(uint8_t) * 4) == -1) return 1;
goto read_error; }
if (read_entity(sock, sr.bind_addr.dns.str, sizeof(char) * sr.bind_addr.dns.len) == -1) s5ctx->cr_cursor += written;
goto read_error; if (s5ctx->cr_cursor < s5ctx->cr_size) return 0;
break;
case ATYP_IPV6: evt_core_mv_fd2 (ctx, fdinfo, "socks5-recv-server-reply");
if (read_entity(sock, sr.bind_addr.ipv6, sizeof(uint8_t) * 16) == -1) return 1;
goto read_error; }
break;
default: int socks5_server_reply_atyp_ipv4(struct evt_core_ctx* ctx, struct evt_core_fdinfo* fdinfo) {
fprintf(stderr, "Unsupported ATYP in server reply\n"); struct socks5_ctx* s5ctx = fdinfo->other;
return -128; size_t fixed_headers_size = (void*)&s5ctx->sr.bind_addr.ipv4 - (void*)&s5ctx->sr;
size_t host_size = sizeof(s5ctx->sr.bind_addr.ipv4);
uint64_t relative_cursor = (s5ctx->sr_cursor - fixed_headers_size);
int nread = 0;
nread = read(fdinfo->fd,
s5ctx->sr.bind_addr.ipv4 + relative_cursor,
host_size - relative_cursor);
if (nread == -1 && errno == EAGAIN) return 1;
if (nread < 0) {
perror("write failed on tcp socket in socks5");
evt_core_mv_fd2(ctx, fdinfo, "socks5-failed");
fdinfo->cat->cb(ctx, fdinfo);
return 1;
}
s5ctx->sr_cursor += nread;
if (s5ctx->sr_cursor < fixed_headers_size + host_size) return 0;
s5ctx->sr_atyp_read = 1;
return 0;
}
int socks5_server_reply_atyp_ipv6(struct evt_core_ctx* ctx, struct evt_core_fdinfo* fdinfo) {
struct socks5_ctx* s5ctx = fdinfo->other;
size_t fixed_headers_size = (void*)&s5ctx->sr.bind_addr.ipv6 - (void*)&s5ctx->sr;
size_t host_size = sizeof(s5ctx->sr.bind_addr.ipv6);
uint64_t relative_cursor = (s5ctx->sr_cursor - fixed_headers_size);
int nread = 0;
nread = read(fdinfo->fd,
s5ctx->sr.bind_addr.ipv6 + relative_cursor,
host_size - relative_cursor);
if (nread == -1 && errno == EAGAIN) return 1;
if (nread < 0) {
perror("write failed on tcp socket in socks5");
evt_core_mv_fd2(ctx, fdinfo, "socks5-failed");
fdinfo->cat->cb(ctx, fdinfo);
return 1;
}
s5ctx->sr_cursor += nread;
if (s5ctx->sr_cursor < fixed_headers_size + host_size) return 0;
s5ctx->sr_atyp_read = 1;
return 0;
}
int socks5_server_reply_atyp_dn(struct evt_core_ctx* ctx, struct evt_core_fdinfo* fdinfo) {
struct socks5_ctx* s5ctx = fdinfo->other;
size_t fixed_headers_size = (void*)&s5ctx->sr.bind_addr.ipv6 - (void*)&s5ctx->sr;
size_t dn_size_size = sizeof(s5ctx->sr.bind_addr.dns.len);
uint64_t relative_cursor = 0;
int nread = 0;
if (s5ctx->sr_cursor < fixed_headers_size + dn_size_size) {
relative_cursor = (s5ctx->sr_cursor - fixed_headers_size);
nread = read(fdinfo->fd, &s5ctx->sr.bind_addr.dns.len + relative_cursor, dn_size_size - relative_cursor);
if (nread == -1 && errno == EAGAIN) return 1;
if (nread < 0) {
perror("write failed on tcp socket in socks5");
evt_core_mv_fd2(ctx, fdinfo, "socks5-failed");
fdinfo->cat->cb(ctx, fdinfo);
return 1;
}
s5ctx->sr_cursor += nread;
return 0;
}
relative_cursor = s5ctx->sr_cursor - fixed_headers_size - sizeof(s5ctx->sr.bind_addr.dns.len);
nread = read(fdinfo->fd, &s5ctx->sr.bind_addr.dns.str + relative_cursor, s5ctx->sr.bind_addr.dns.len - relative_cursor);
return 0;
}
int on_socks5_recv_server_reply(struct evt_core_ctx* ctx, struct evt_core_fdinfo* fdinfo) {
struct socks5_ctx* s5ctx = fdinfo->other;
int readn = 0;
size_t fixed_headers_size = (void*)&s5ctx->sr.bind_addr - (void*)&s5ctx->sr;
size_t fixed_tail_size = (void*)(&s5ctx->sr + 1) - (void*)&s5ctx->sr.port ;
if (s5ctx->sr_cursor < fixed_headers_size) {
readn = read(fdinfo->fd, &s5ctx->sr + s5ctx->sr_cursor, fixed_headers_size - s5ctx->sr_cursor);
if (readn == -1 && errno == EAGAIN) return 1;
if (readn < 0) goto move_to_failed;
s5ctx->sr_cursor += readn;
return 0; // Needed as we might have not read enough bytes and free us from writing a loop
}
if (!s5ctx->sr_atyp_read) {
if (s5ctx->sr.atyp == ATYP_IPV4) return socks5_server_reply_atyp_ipv4(ctx, fdinfo);
else if (s5ctx->sr.atyp == ATYP_IPV6) return socks5_server_reply_atyp_ipv6(ctx, fdinfo);
else if (s5ctx->sr.atyp == ATYP_DOMAINNAME) return socks5_server_reply_atyp_dn(ctx, fdinfo);
else goto move_to_failed;
}
move_to_failed:
evt_core_mv_fd2 (ctx, fdinfo, "socks5-failed");
fdinfo->cat->cb(ctx, fdinfo);
return 1;
/*int res;
struct server_reply sr = {0};
res = read_entity(sock, &sr, sizeof(uint8_t) * 4);
if (res == -1) goto read_error;
switch(sr.atyp) {
case ATYP_IPV4:
if (read_entity(sock, sr.bind_addr.ipv4, sizeof(uint8_t) * 4) == -1)
goto read_error;
break;
case ATYP_DOMAINNAME:
if (read_entity(sock, &sr.bind_addr.dns.len, sizeof(uint8_t) * 4) == -1)
goto read_error;
if (read_entity(sock, sr.bind_addr.dns.str, sizeof(char) * sr.bind_addr.dns.len) == -1)
goto read_error;
break;
case ATYP_IPV6:
if (read_entity(sock, sr.bind_addr.ipv6, sizeof(uint8_t) * 16) == -1)
goto read_error;
break;
default:
fprintf(stderr, "Unsupported ATYP in server reply\n");
return -128;
} }
res = read_entity(sock, &sr.port, sizeof(uint16_t)); res = read_entity(sock, &sr.port, sizeof(uint16_t));
if (res == -1) { if (res == -1) {
@ -153,27 +294,7 @@ int socks5_reply(int sock) {
read_error: read_error:
fprintf(stderr, "Unable to read ATYP\n"); fprintf(stderr, "Unable to read ATYP\n");
return -128; return -128;*/
}
int socks5_connect_dns(int sock, char* addr, uint16_t port) {
char buffer[262];
size_t domainLength = strlen(addr);
if (domainLength > 255) {
fprintf(stderr, "domain is too long\n");
exit(EXIT_FAILURE);
}
struct client_request cr = { 0x05, CMD_CONNECT, 0x00, ATYP_DOMAINNAME, (uint8_t)domainLength, addr, htons(port) };
size_t written = 0;
fill_buffer(&written, buffer, &cr, 5*sizeof(uint8_t));
fill_buffer(&written, buffer, cr.dst_addr, cr.dst_addr_len*sizeof(char));
fill_buffer(&written, buffer, &cr.port, sizeof(uint16_t));
if (written != write(sock, buffer, written)) {
fprintf(stderr, "partial/failed write\n");
return -1;
}
return 0;
} }
char* socks5_rep (enum socks5_rep rep) { char* socks5_rep (enum socks5_rep rep) {

View file

@ -42,7 +42,7 @@ enum methods {
union socks5_addr { union socks5_addr {
struct { struct {
uint8_t len; uint8_t len;
char* str; char str[256];
} dns; } dns;
uint8_t ipv4[4]; uint8_t ipv4[4];
uint8_t ipv6[16]; uint8_t ipv6[16];