Hello, about one or two months ago, I had the problem that /proc/sys/net/ipv4/ip_dynaddr did not work. I analyzed the problem and somehow came to a solution which I have forgotten. But a patch which solved the problem against 2.4.1 which also works for 2.4.2-pre4 remained. Here it is. Xuân.
--- linux/net/ipv4/tcp_ipv4.c.orig Tue Jan 30 11:37:56 2001 +++ linux/net/ipv4/tcp_ipv4.c Tue Jan 30 13:31:14 2001 @@ -1774,6 +1774,11 @@ u32 daddr; int err; + if (sysctl_ip_dynaddr > 2) { + printk(KERN_INFO "tcp_v4_rebuild_header(): sysctl_ip_dynaddr=%d, sk->userlocks=0x%x, rt==0x%x, src=%d.%d.%d.%d, sk->state=%d,sk->userlocks=0x%x.\n", + sysctl_ip_dynaddr, sk->userlocks,rt,NIPQUAD(sk->saddr),sk->state,sk->userlocks); + } + /* Route is OK, nothing to do. */ if (rt != NULL) return 0; @@ -1783,9 +1788,26 @@ if(sk->protinfo.af_inet.opt && sk->protinfo.af_inet.opt->srr) daddr = sk->protinfo.af_inet.opt->faddr; + if ((sysctl_ip_dynaddr) && (sk->state == TCP_SYN_SENT) && (!(sk->userlocks & SOCK_BINDADDR_LOCK)) ) { + err = tcp_v4_reselect_saddr(sk); + + if (sysctl_ip_dynaddr > 2) { + printk(KERN_INFO "tcp_v4_rebuild_header(): tcp_v4_reselect_saddr(sk)=%d.\n",err); + } + + if (err!=0) { + sk->err_soft=-err; + /* sk->error_report(sk); */ + } + } + err = ip_route_output(&rt, daddr, sk->saddr, RT_TOS(sk->protinfo.af_inet.tos) | RTO_CONN | sk->localroute, sk->bound_dev_if); + if (sysctl_ip_dynaddr > 2) { + printk(KERN_INFO "tcp_v4_rebuild_header(): err=%d.\n", + err); + } if (!err) { __sk_dst_set(sk, &rt->u.dst); /* sk->route_caps = rt->u.dst.dev->features; */