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Date:      Mon, 14 Feb 2000 14:33:06 -0800
From:      Nathan <nboeger@getrelevant.com>
To:        darcy@ok-connect.com, "freebsd-net@FreeBSD.ORG" <freebsd-net@FreeBSD.ORG>
Subject:   Re: HELP ! programing routes ??
Message-ID:  <38A882A2.30A31434@getrelevant.com>
References:  R01YxYj

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darcy@ok-connect.com wrote:

> ----- ORIGINAL INTERNET MAIL FOLLOWS 02/14/2000 02:21 PM PST -----
> From:    darcy@ok-connect.com
> To:      nboeger
>
> Well why not just exec("route add default xxx.xxx.xxx.xxx");
>
> At 02:07 PM 2/14/00 -0800, you wrote:
> >Sorry if this is a repeat !
> >
> >
> >I have a question, I need to write a small program that sets the default
> >
> >gw. It is written in C and I have looked at several way to do it. One
> >way is using ioctl but that way seems a little "old" and not very well
> >documented. Here is a simple snippet of my code, now when I run it I get
> >
> >an error "error 22" invalid arg. Does anyone have experience with this
> >and can point out what I am doing wrong ? I did have it to where it
> >would work but the kernel never added my netmask to the routing table.
> >So the route would kinda "hang" their and not do anything. I did tell it
> >
> >that it was being sent but..... also the flags never where set proper on
> >
> >the route (when doing route -dvn flush )
> >
> >
> >Any help would be great !  (oh if this looks familiar, I learned this
> >from reading both ruote.c and netstat.c.  )
> >
> >struct rt_data_msg{
> >        struct rt_msghdr add_rtm;
> >        union{
> >                struct sockaddr sa;
> >                struct sockaddr_in sin;
> >                struct sockaddr_dl sdl;
> >        }rt_dst, rt_gate, rt_mask;
> >};
> >
> >int set_droute(char *gw){
> >
> >        int sockfd, i, err = 0;
> >        int flags = 0, r_addrs = 0;
> >        u_long inits;
> >        char t_gw[32];
> >        register int l;
> >        struct rt_data_msg add_rt;
> >        pid_t pid;
> >
> >        /* check to see if we have a gateway address or quit */
> >        if(!gw){
> >                ERR("set_droute: FREEBSD no route sent ! %d");
> >                return(BAD);
> >        }
> >        else{
> >                /* convet this address if not valid quit */
> >                if((inet_aton(gw, &so_gate.sin.sin_addr)) < 0){
> >                        ERR("set_droute: FREEBSD route not valid ! %d");
> >
> >                        return(BAD);
> >                }
> >        }
> >
> >        memset(&add_rt, 0, sizeof(struct rt_data_msg));
> >
> >        /* check to see if thier is an existing route or not make an
> >entry from scratch */
> >        if( (i = get_droute(t_gw)) == BAD){
> >
> >                /* make the address and netmasks */
> >
> >                if((inet_aton("0.0.0.0", &add_rt.rt_mask.sin.sin_addr))
> >< 0){ err++;  }
> >                if((inet_aton("0.0.0.0", &add_rt.rt_dst.sin.sin_addr)) <
> >
> >0) { err++;  }
> >                if((inet_aton(gw, &add_rt.rt_gate.sin.sin_addr)) < 0){
> >err++; }
> >                if(err > 0){
> >                        ERR("get_droute: FREEBSD cannot set mask or dst
> >or gw invalid addresses %d");
> >                        return(BAD);
> >                }
> >
> >                inits = RTV_EXPIRE;
> >                inits |=  RTV_RPIPE;
> >                inits |= RTV_SPIPE;
> >                inits |= RTV_SSTHRESH;
> >
> >                r_addrs = RTAX_DST;
> >                r_addrs |= RTAX_GATEWAY;
> >                r_addrs |= RTAX_NETMASK;
> >
> >                flags = RTF_UP;
> >                flags |= RTF_GATEWAY;
> >                flags |= RTF_STATIC;
> >                flags |= RTF_PRCLONING;
> >
> >                /* add thier size */
> >#define ADD_SIZE(w) l = ROUNDUP(w.sa.sa_len)
> >#define ROUNDUP(a)    ((a) > 0 ? (1 + (((a) - 1) | (sizeof(long) - 1)))
> >: sizeof(long));
> >
> >                ADD_SIZE(add_rt.rt_dst);
> >                ADD_SIZE(add_rt.rt_gate);
> >                ADD_SIZE(add_rt.rt_mask);
> >
> >                /* add their address family */
> >#define ADD_FAM(x)      x.sin.sin_family = AF_INET;
> >                ADD_FAM(add_rt.rt_dst);
> >                ADD_FAM(add_rt.rt_gate);
> >                ADD_FAM(add_rt.rt_mask);
> >                ADD_FAM(add_rt.rt_genmask);
> >
> >                /* set up all of the flags and tables */
> >#define RD add_rt.add_rtm
> >                RD.rtm_msglen = l;
> >                RD.rtm_version = RTM_VERSION;
> >                RD.rtm_type = RTM_ADD;
> >                RD.rtm_flags = flags;
> >                RD.rtm_addrs = rtm_addrs;
> >                RD.rtm_inits = RTF_GATEWAY;
> >                RD.rtm_pid = pid = getpid();
> >                RD.rtm_seq = ++SEQ;
> >
> >                if( (sockfd = socket(PF_ROUTE, SOCK_RAW, 0)) < 0){
> >                        ERR("set_droute: FREEBSD cannot open socket
> >%d");
> >                }
> >                /* send it to the kernel */
> >                i = write(sockfd, (char *)&add_rt, l);
> >                syslog(LOG_ERR, "errno = %d ", errno);
> >        }
> >        else{
> >                /* get a buffer for the data */
> >                ERR("get_droute returned ok %d ");
> >        }
> >
> >        return(GOOD);
> >}
> >
> >
> >Thank you
> >
> >nathan
> >
> >
> >
> >To Unsubscribe: send mail to majordomo@FreeBSD.org
> >with "unsubscribe freebsd-net" in the body of the message
> >
> >

Beacuse that would be a security leak and other reasons of the like. What I
need to do is be able to set this from within my program with out calling
popen or exec .....

Can you see any problems in the code ?

thank you

nathan



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