--- /dev/null
+/*
+ * udp-preload.c - testing mock library for secnet udp
+ * This file is part of secnet.
+ *
+ * Copyright (C) 1998,2003-2004,2012,2017,2019 Ian Jackson
+ *
+ * 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 3, 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
+ * version 3 along with secnet; if not, see
+ * https://www.gnu.org/licenses/gpl.html.
+ */
+
+#define _GNU_SOURCE
+
+#include <dlfcn.h>
+#include <stdio.h>
+#include <sys/types.h>
+#include <unistd.h>
+#include <errno.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/socket.h>
+#include <netinet/in.h>
+#include <sys/un.h>
+#include <arpa/inet.h>
+
+#define STDERRSTR_CONST(m) write(2,m,sizeof(m)-1)
+#define STDERRSTR_STRING(m) write(2,m,strlen(m))
+
+typedef void anyfn_type(void);
+
+static anyfn_type *find_any(const char *name) {
+ static const char *dlerr;
+ anyfn_type *kv;
+
+ kv= dlsym(RTLD_NEXT,name); if (kv) return kv;
+ dlerr= dlerror(); if (!dlerr) dlerr= "dlsym() failed for no reason";
+ STDERRSTR_CONST("udp-preload: error finding original version of ");
+ STDERRSTR_STRING(name);
+ STDERRSTR_CONST(": ");
+ STDERRSTR_STRING(dlerr);
+ STDERRSTR_STRING("\n");
+ errno= ENOSYS;
+ return 0;
+}
+
+#define socket_args int domain, int type, int protocol
+#define close_args int fd
+#define bind_args int fd, const struct sockaddr *addr, socklen_t addrlen
+#define sendto_args int fd, const void *buf, size_t len, int flags, \
+ const struct sockaddr *addr, socklen_t addrlen
+#define recvfrom_args int fd, void *buf, size_t len, int flags, \
+ struct sockaddr *addr, socklen_t *addrlen
+#define setsockopt_args int fd, int level, int optname, \
+ const void *optval, socklen_t optlen
+#define getsockname_args int fd, struct sockaddr *addr, socklen_t *addrlen
+#define WRAPS(X) \
+ X(socket, int, (domain,type,protocol)) \
+ X(close, int, (fd)) \
+ X(bind, int, (fd,addr,addrlen)) \
+ X(sendto, ssize_t, (fd,buf,len,flags,addr,addrlen)) \
+ X(recvfrom, ssize_t, (fd,buf,len,flags,addr,addrlen)) \
+ X(setsockopt, int, (fd,level,optname,optval,optlen)) \
+ X(getsockname,int, (fd,addr,addrlen))
+
+#define DEF_OLD(fn,rt,args) \
+ typedef rt fn##_fn_type(fn##_args); \
+ static rt find_##fn(fn##_args); \
+ static fn##_fn_type find_##fn, *old_##fn=find_##fn; \
+ static rt find_##fn(fn##_args) { \
+ anyfn_type *anyfn; \
+ anyfn= find_any(#fn); if (!anyfn) return -1; \
+ old_##fn= (fn##_fn_type*)anyfn; \
+ return old_##fn args; \
+ }
+
+WRAPS(DEF_OLD)
+
+#define WRAP(fn) int fn(fn##_args)
+#define TWRAP(fn) fn(fn##_args)
+
+typedef struct{
+ int af;
+} fdinfo;
+static fdinfo **table;
+static int tablesz;
+
+static fdinfo *lookup(int fd) {
+ if (fd<0 || fd>=tablesz) return 0;
+ return table[fd];
+}
+
+#define ADDRPORTSTRLEN (INET6_ADDRSTRLEN+1+5) /* not including nul */
+
+static int addrport2str(char buf[ADDRPORTSTRLEN+1],
+ const struct sockaddr *addr, socklen_t addrlen) {
+ const void *addrv=addr;
+ const void *iav;
+ const struct sockaddr_in *sin;
+ const struct sockaddr_in6 *sin6;
+ uint16_t port;
+ socklen_t el;
+ switch (addr->sa_family) {
+ case AF_INET: sin =addrv; el=sizeof(*sin ); iav=&sin ->sin_addr ; port=sin ->sin_port ; break;
+ case AF_INET6: sin6=addrv; el=sizeof(*sin6); iav=&sin6->sin6_addr; port=sin6->sin6_port; break;
+ default: errno=ESRCH; return -1;
+ }
+//fprintf(stderr,"af=%lu el=%lu addrlen=%lu\n",
+// (unsigned long)addr->sa_family,
+// (unsigned long)el,
+// (unsigned long)addrlen);
+ if (addrlen!=el) { errno=EINVAL; return -1; }
+ char *p=buf;
+ if (!inet_ntop(addr->sa_family,iav,p,INET6_ADDRSTRLEN)) return -1;
+ p+=strlen(p);
+ sprintf(p,",%u",(unsigned)ntohs(port));
+ return 0;
+}
+
+static int str2addrport(char *str,
+ struct sockaddr *addr, socklen_t *addrlen) {
+ union {
+ struct sockaddr_in sin;
+ struct sockaddr_in6 sin6;
+ } si;
+
+ memset(&si,0,sizeof(si));
+
+ int af;
+ void *iav;
+ uint16_t *portp;
+ socklen_t al;
+ switch (str[strcspn(str,".:")]) {
+ case '.': af=AF_INET ; iav=&si.sin .sin_addr ; al=sizeof(si.sin ); portp=&si.sin .sin_port ; break;
+ case ':': af=AF_INET6; iav=&si.sin6.sin6_addr; al=sizeof(si.sin6); portp=&si.sin6.sin6_port; break;
+ default: errno=ESRCH; return -1;
+ }
+ si.sin.sin_family=af;
+
+ char *comma=strchr(str,',');
+ if (!comma) { errno=ESRCH; return -1; }
+ *comma++=0;
+ int r=inet_pton(af,str,iav);
+//fprintf(stderr,"inet_pton(%d,\"%s\",)=%d\n",af,str,r);
+ if (r<0) return -1;
+ if (r==0) { errno=ENOTTY; return -1; }
+
+ char *ep;
+ errno=0;
+ unsigned long port=strtoul(comma,&ep,10);
+ if (ep==comma || *ep || errno || port>65536) { errno=ESRCH; return -1; }
+ *portp= htons(port);
+
+ if (addr) memcpy(addr,&si, *addrlen<al ? *addrlen : al);
+ *addrlen=al;
+ return 0;
+}
+
+static char *sun_prep(struct sockaddr_un *sun) {
+ const char *dir=getenv("UDP_PRELOAD_DIR");
+ if (!dir) { errno=ECHILD; return 0; }
+
+ memset(sun,0,sizeof(*sun));
+ sun->sun_family=AF_UNIX;
+ int dl = strlen(dir);
+ if (dl + 1 + ADDRPORTSTRLEN + 1 > sizeof(sun->sun_path)) {
+ errno=ENAMETOOLONG; return 0;
+ }
+ strcpy(sun->sun_path,dir);
+ char *p=sun->sun_path+dl;
+ *p++='/';
+ return p;
+}
+
+WRAP(socket) {
+ if (!((domain==AF_INET || domain==AF_INET6) &&
+ type==SOCK_DGRAM))
+ return old_socket(domain,type,protocol);
+ int fd=socket(AF_UNIX,SOCK_DGRAM,0);
+ if (fd<0) return fd;
+ if (fd>=tablesz) {
+ int newsz=(fd+1)*2;
+ table=realloc(table,newsz*sizeof(*table));
+ if (!table) goto fail;
+ while (tablesz<newsz) table[tablesz++]=0;
+ }
+ free(table[fd]);
+ table[fd]=malloc(sizeof(*table[fd]));
+ if (!table[fd]) goto fail;
+ table[fd]->af=domain;
+ return fd;
+
+ fail:
+ close(fd);
+ return -1;
+}
+
+WRAP(close) {
+ if (fd>=0 && fd<tablesz) {
+ free(table[fd]);
+ table[fd]=0;
+ }
+ return old_close(fd);
+}
+
+WRAP(bind) {
+ fdinfo *ent=lookup(fd);
+ if (!ent) return old_bind(fd,addr,addrlen);
+ struct sockaddr_un sun;
+ char *p=sun_prep(&sun);
+ if (addrport2str(p,addr,addrlen)) return -1;
+//fprintf(stderr,"binding %s\n",sun.sun_path);
+ if (unlink(sun.sun_path) && errno!=ENOENT) return -1;
+ return old_bind(fd,(const void*)&sun,sizeof(sun));
+}
+
+WRAP(setsockopt) {
+ fdinfo *ent=lookup(fd);
+ if (!ent) return old_setsockopt(fd,level,optname,optval,optlen);
+ if (ent->af==AF_INET6 && level==IPPROTO_IPV6 && optname==IPV6_V6ONLY
+ && optlen==sizeof(int) && *(int*)optval==1) {
+ return 0;
+ }
+ errno=ENOTTY;
+ return -1;
+}
+
+WRAP(getsockname) {
+ fdinfo *ent=lookup(fd);
+ if (!ent) return old_getsockname(fd,addr,addrlen);
+ struct sockaddr_un sun;
+ socklen_t sunlen=sizeof(sun);
+ if (old_getsockname(fd,(void*)&sun,&sunlen)) return -1;
+ if (sun.sun_family!=AF_UNIX || sunlen>sizeof(sun)) {
+//fprintf(stderr,"old_getsockname af=%lu sunlen=%lu\n",
+// (unsigned long)sun.sun_family,
+// (unsigned long)sunlen);
+ errno=EDOM; return -1;
+ }
+ char *slash=strrchr(sun.sun_path,'/');
+ if (str2addrport(slash ? slash+1 : sun.sun_path,
+ addr,addrlen)) return -1;
+ return 0;
+}
+
+ssize_t TWRAP(sendto) {
+ fdinfo *ent=lookup(fd);
+ if (!ent) return old_sendto(fd,buf,len,flags,addr,addrlen);
+
+ if (flags) { errno=ENOEXEC; return -1; }
+
+ const char *leaf=getenv("UDP_PRELOAD_SERVER");
+ if (!leaf) leaf="udp";
+ if (strlen(leaf) > ADDRPORTSTRLEN) { errno=ENAMETOOLONG; return -1; }
+ struct sockaddr_un sun;
+ char *p=sun_prep(&sun);
+ strcpy(p,leaf);
+
+ char tbuf[ADDRPORTSTRLEN+1];
+ memset(tbuf,0,sizeof(tbuf));
+ if (addrport2str(tbuf,addr,addrlen)) return -1;
+
+ struct iovec iov[2];
+ iov[0].iov_base=tbuf;
+ iov[0].iov_len=sizeof(tbuf);
+ iov[1].iov_base=(void*)buf;
+ iov[1].iov_len=len;
+
+ struct msghdr m;
+ memset(&m,0,sizeof(m));
+ m.msg_name=&sun;
+ m.msg_namelen=sizeof(sun);
+ m.msg_iov=iov;
+ m.msg_iovlen=2;
+
+ return sendmsg(fd,&m,0);
+}
+
+ssize_t TWRAP(recvfrom) {
+ fdinfo *ent=lookup(fd);
+ if (!ent) return old_recvfrom(fd,buf,len,flags,addr,addrlen);
+
+//fprintf(stderr,"recvfrom %d len=%lu flags=%d al=%lu\n",
+// fd, (unsigned long)len, flags, (unsigned long)*addrlen);
+
+ if (flags) { errno=ENOEXEC; return -1; }
+
+ char tbuf[ADDRPORTSTRLEN+1];
+
+ struct iovec iov[2];
+ iov[0].iov_base=tbuf;
+ iov[0].iov_len=sizeof(tbuf);
+ iov[1].iov_base=buf;
+ iov[1].iov_len=len;
+
+ struct msghdr m;
+ memset(&m,0,sizeof(m));
+ m.msg_iov=iov;
+ m.msg_iovlen=2;
+
+ ssize_t rr=recvmsg(fd,&m,0);
+ if (rr==-1) return rr;
+ if (rr<sizeof(tbuf)) { errno=ENXIO; return -1; }
+ if (tbuf[ADDRPORTSTRLEN]) { errno=E2BIG; return -1; }
+ if (str2addrport(tbuf,addr,addrlen)) {
+ fprintf(stderr, "recvfrom str2addrport `%s' %s\n",tbuf,
+ strerror(errno));
+ return -1;
+ }
+
+ rr -= sizeof(tbuf);
+//fprintf(stderr,"recvfrom %s %lu ok\n",tbuf,(unsigned long)rr);
+ return rr;
+}
~ianmdlvl / secnet.git / blobdiff