/* Socket wrapper library. Passes all socket communication over unix domain sockets if the environment variable SOCKET_WRAPPER_DIR is set. Copyright (C) Jelmer Vernooij 2005 This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */ #ifdef _SAMBA_BUILD_ #include "includes.h" #include "system/network.h" #else #include <sys/types.h> #include <sys/socket.h> #include <errno.h> #include <sys/un.h> #include <netinet/in.h> #include <netinet/tcp.h> #include <stdlib.h> #include <unistd.h> #include <string.h> #include <stdio.h> #include "dlinklist.h" #endif /* LD_PRELOAD doesn't work yet, so REWRITE_CALLS is all we support * for now */ #define REWRITE_CALLS #ifdef REWRITE_CALLS #define real_accept accept #define real_connect connect #define real_bind bind #define real_getpeername getpeername #define real_getsockname getsockname #define real_getsockopt getsockopt #define real_setsockopt setsockopt #define real_recvfrom recvfrom #define real_sendto sendto #define real_socket socket #define real_close close #endif static struct sockaddr *sockaddr_dup(const void *data, socklen_t len) { struct sockaddr *ret = (struct sockaddr *)malloc(len); memcpy(ret, data, len); return ret; } struct socket_info { int fd; int domain; int type; int protocol; int bound; char *path; char *tmp_path; struct sockaddr *myname; socklen_t myname_len; struct sockaddr *peername; socklen_t peername_len; struct socket_info *prev, *next; }; static struct socket_info *sockets = NULL; static int convert_un_in(const struct sockaddr_un *un, struct sockaddr_in *in, socklen_t *len) { unsigned int prt; const char *p; int type; if ((*len) < sizeof(struct sockaddr_in)) { return 0; } in->sin_family = AF_INET; in->sin_port = 1025; /* Default to 1025 */ p = strchr(un->sun_path, '/'); if (p) p++; else p = un->sun_path; if (sscanf(p, "sock_ip_%d_%u", &type, &prt) == 2) { in->sin_port = htons(prt); } in->sin_addr.s_addr = htonl(INADDR_LOOPBACK); *len = sizeof(struct sockaddr_in); return 0; } static int convert_in_un(int type, const struct sockaddr_in *in, struct sockaddr_un *un) { uint16_t prt = ntohs(in->sin_port); snprintf(un->sun_path, sizeof(un->sun_path), "%s/sock_ip_%d_%u", getenv("SOCKET_WRAPPER_DIR"), type, prt); return 0; } static struct socket_info *find_socket_info(int fd) { struct socket_info *i; for (i = sockets; i; i = i->next) { if (i->fd == fd) return i; } return NULL; } static int sockaddr_convert_to_un(const struct socket_info *si, const struct sockaddr *in_addr, socklen_t in_len, struct sockaddr_un *out_addr) { if (!out_addr) return 0; out_addr->sun_family = AF_UNIX; switch (in_addr->sa_family) { case AF_INET: return convert_in_un(si->type, (const struct sockaddr_in *)in_addr, out_addr); case AF_UNIX: memcpy(out_addr, in_addr, sizeof(*out_addr)); return 0; default: break; } errno = EAFNOSUPPORT; return -1; } static int sockaddr_convert_from_un(const struct socket_info *si, const struct sockaddr_un *in_addr, socklen_t un_addrlen, int family, struct sockaddr *out_addr, socklen_t *out_len) { if (out_addr == NULL || out_len == NULL) return 0; if (un_addrlen == 0) { *out_len = 0; return 0; } switch (family) { case AF_INET: return convert_un_in(in_addr, (struct sockaddr_in *)out_addr, out_len); case AF_UNIX: memcpy(out_addr, in_addr, sizeof(*in_addr)); *out_len = sizeof(*in_addr); return 0; default: break; } errno = EAFNOSUPPORT; return -1; } int swrap_socket(int domain, int type, int protocol) { struct socket_info *si; int fd; if (!getenv("SOCKET_WRAPPER_DIR")) { return real_socket(domain, type, protocol); } fd = real_socket(AF_UNIX, type, 0); if (fd == -1) return -1; si = calloc(1, sizeof(struct socket_info)); si->domain = domain; si->type = type; si->protocol = protocol; si->fd = fd; DLIST_ADD(sockets, si); return si->fd; } int swrap_accept(int s, struct sockaddr *addr, socklen_t *addrlen) { struct socket_info *parent_si, *child_si; int fd; socklen_t un_addrlen = sizeof(struct sockaddr_un); struct sockaddr_un un_addr; int ret; parent_si = find_socket_info(s); if (!parent_si) { return real_accept(s, addr, addrlen); } ret = real_accept(s, (struct sockaddr *)&un_addr, &un_addrlen); if (ret == -1) return ret; fd = ret; ret = sockaddr_convert_from_un(parent_si, &un_addr, un_addrlen, parent_si->domain, addr, addrlen); if (ret == -1) return ret; child_si = malloc(sizeof(struct socket_info)); memset(child_si, 0, sizeof(*child_si)); child_si->fd = fd; if (addr && addrlen) { child_si->myname_len = *addrlen; child_si->myname = sockaddr_dup(addr, *addrlen); } return fd; } int swrap_connect(int s, const struct sockaddr *serv_addr, socklen_t addrlen) { int ret; struct sockaddr_un un_addr; struct socket_info *si = find_socket_info(s); if (!si) { return real_connect(s, serv_addr, addrlen); } /* only allow pseudo loopback connections */ if (serv_addr->sa_family == AF_INET && ((const struct sockaddr_in *)serv_addr)->sin_addr.s_addr != htonl(INADDR_LOOPBACK)) { errno = ENETUNREACH; return -1; } ret = sockaddr_convert_to_un(si, (const struct sockaddr *)serv_addr, addrlen, &un_addr); if (ret == -1) return -1; ret = real_connect(s, (struct sockaddr *)&un_addr, sizeof(struct sockaddr_un)); if (ret == 0) { si->peername_len = addrlen; si->peername = sockaddr_dup(serv_addr, addrlen); } return ret; } int swrap_bind(int s, const struct sockaddr *myaddr, socklen_t addrlen) { int ret; struct sockaddr_un un_addr; struct socket_info *si = find_socket_info(s); if (!si) { return real_bind(s, myaddr, addrlen); } ret = sockaddr_convert_to_un(si, (const struct sockaddr *)myaddr, addrlen, &un_addr); if (ret == -1) return -1; unlink(un_addr.sun_path); ret = real_bind(s, (struct sockaddr *)&un_addr, sizeof(struct sockaddr_un)); if (ret == 0) { si->myname_len = addrlen; si->myname = sockaddr_dup(myaddr, addrlen); si->bound = 1; } return ret; } int swrap_getpeername(int s, struct sockaddr *name, socklen_t *addrlen) { struct socket_info *si = find_socket_info(s); if (!si) { return real_getpeername(s, name, addrlen); } if (!si->peername) { errno = ENOTCONN; return -1; } memcpy(name, si->peername, si->peername_len); *addrlen = si->peername_len; return 0; } int swrap_getsockname(int s, struct sockaddr *name, socklen_t *addrlen) { struct socket_info *si = find_socket_info(s); if (!si) { return real_getsockname(s, name, addrlen); } memcpy(name, si->myname, si->myname_len); *addrlen = si->myname_len; return 0; } int swrap_getsockopt(int s, int level, int optname, void *optval, socklen_t *optlen) { struct socket_info *si = find_socket_info(s); if (!si) { return real_getsockopt(s, level, optname, optval, optlen); } if (level == SOL_SOCKET) { return real_getsockopt(s, level, optname, optval, optlen); } switch (si->domain) { case AF_UNIX: return real_getsockopt(s, level, optname, optval, optlen); default: errno = ENOPROTOOPT; return -1; } } int swrap_setsockopt(int s, int level, int optname, const void *optval, socklen_t optlen) { struct socket_info *si = find_socket_info(s); if (!si) { return real_setsockopt(s, level, optname, optval, optlen); } if (level == SOL_SOCKET) { return real_setsockopt(s, level, optname, optval, optlen); } switch (si->domain) { case AF_UNIX: return real_setsockopt(s, level, optname, optval, optlen); case AF_INET: /* Silence some warnings */ #ifdef TCP_NODELAY if (optname == TCP_NODELAY) return 0; #endif default: errno = ENOPROTOOPT; return -1; } } ssize_t swrap_recvfrom(int s, void *buf, size_t len, int flags, struct sockaddr *from, socklen_t *fromlen) { struct sockaddr_un un_addr; socklen_t un_addrlen = sizeof(un_addr); int ret; struct socket_info *si = find_socket_info(s); if (!si) { return real_recvfrom(s, buf, len, flags, from, fromlen); } ret = real_recvfrom(s, buf, len, flags, (struct sockaddr *)&un_addr, &un_addrlen); if (ret == -1) return ret; if (sockaddr_convert_from_un(si, &un_addr, un_addrlen, si->domain, from, fromlen) == -1) { return -1; } return ret; } ssize_t swrap_sendto(int s, const void *buf, size_t len, int flags, const struct sockaddr *to, socklen_t tolen) { struct sockaddr_un un_addr; int ret; struct socket_info *si = find_socket_info(s); if (!si) { return real_sendto(s, buf, len, flags, to, tolen); } /* using sendto() on an unbound DGRAM socket would give the recipient no way to reply, as unlike UDP, a unix domain socket can't auto-assign emphemeral port numbers, so we need to assign it here */ if (si->bound == 0 && si->type == SOCK_DGRAM) { int i; un_addr.sun_family = AF_UNIX; for (i=0;i<1000;i++) { snprintf(un_addr.sun_path, sizeof(un_addr.sun_path), "%s/sock_ip_%u_%u", getenv("SOCKET_WRAPPER_DIR"), SOCK_DGRAM, i + 10000); if (bind(si->fd, (struct sockaddr *)&un_addr, sizeof(un_addr)) == 0) { si->tmp_path = strdup(un_addr.sun_path); si->bound = 1; break; } } if (i == 1000) { return -1; } } ret = sockaddr_convert_to_un(si, to, tolen, &un_addr); if (ret == -1) return -1; ret = real_sendto(s, buf, len, flags, (struct sockaddr *)&un_addr, sizeof(un_addr)); return ret; } int swrap_close(int fd) { struct socket_info *si = find_socket_info(fd); if (si) { DLIST_REMOVE(sockets, si); free(si->path); free(si->myname); free(si->peername); if (si->tmp_path) { unlink(si->tmp_path); free(si->tmp_path); } free(si); } return real_close(fd); }