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author | peter <peter@FreeBSD.org> | 1997-11-16 04:52:19 +0000 |
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committer | peter <peter@FreeBSD.org> | 1997-11-16 04:52:19 +0000 |
commit | 594e73c3109178aa1c5317785aaa284a0c135ff4 (patch) | |
tree | 1abde20e1d717a2bf3509de2189cbe7fa3c9f91e /contrib/ipfilter/ip_ftp_pxy.c | |
parent | c4dc16ff2222e864e5ab4d236e0de3a2cb5b54da (diff) | |
download | FreeBSD-src-594e73c3109178aa1c5317785aaa284a0c135ff4.zip FreeBSD-src-594e73c3109178aa1c5317785aaa284a0c135ff4.tar.gz |
Import ipfilter 3.2.1 (update from 3.1.8)
Diffstat (limited to 'contrib/ipfilter/ip_ftp_pxy.c')
-rw-r--r-- | contrib/ipfilter/ip_ftp_pxy.c | 161 |
1 files changed, 113 insertions, 48 deletions
diff --git a/contrib/ipfilter/ip_ftp_pxy.c b/contrib/ipfilter/ip_ftp_pxy.c index 48196e9..5d6ce1f 100644 --- a/contrib/ipfilter/ip_ftp_pxy.c +++ b/contrib/ipfilter/ip_ftp_pxy.c @@ -1,5 +1,6 @@ /* - * Simple FTP transparent proxy for in-kernel. + * Simple FTP transparent proxy for in-kernel use. For use with the NAT + * code. */ #define isdigit(x) ((x) >= '0' && (x) <= '9') @@ -10,6 +11,29 @@ #define IPF_MAXPORTLEN 30 +int ippr_ftp_init __P((fr_info_t *, ip_t *, tcphdr_t *, + ap_session_t *, nat_t *)); +int ippr_ftp_in __P((fr_info_t *, ip_t *, tcphdr_t *, + ap_session_t *, nat_t *)); +int ippr_ftp_out __P((fr_info_t *, ip_t *, tcphdr_t *, + ap_session_t *, nat_t *)); +u_short ipf_ftp_atoi __P((char **)); + + +int ippr_ftp_init __P((fr_info_t *, ip_t *, tcphdr_t *, ap_session_t *, + nat_t *)); +int ippr_ftp_in __P((fr_info_t *, ip_t *, tcphdr_t *, ap_session_t *, + nat_t *)); +int ippr_ftp_out __P((fr_info_t *, ip_t *, tcphdr_t *, ap_session_t *, + nat_t *)); + +u_short ipf_ftp_atoi __P((char **)); + + + +/* + * FTP application proxy initialization. + */ int ippr_ftp_init(fin, ip, tcp, aps, nat) fr_info_t *fin; ip_t *ip; @@ -30,13 +54,18 @@ tcphdr_t *tcp; ap_session_t *aps; nat_t *nat; { - int ch = 0; u_long sum1, sum2; + short sel; - if (tcp->th_dport != aps->aps_dport) { + if (tcp->th_sport == aps->aps_dport) { sum2 = (u_long)ntohl(tcp->th_ack); - if (aps->aps_seqoff && (sum2 > aps->aps_after)) { - sum1 = (u_long)aps->aps_seqoff; + sel = aps->aps_sel; + if ((aps->aps_after[!sel] > aps->aps_after[sel]) && + (sum2 > aps->aps_after[!sel])) { + sel = aps->aps_sel = !sel; /* switch to other set */ + } + if (aps->aps_seqoff[sel] && (sum2 > aps->aps_after[sel])) { + sum1 = (u_long)aps->aps_seqoff[sel]; tcp->th_ack = htonl(sum2 - sum1); return 2; } @@ -45,6 +74,12 @@ nat_t *nat; } +/* + * ipf_ftp_atoi - implement a version of atoi which processes numbers in + * pairs separated by commas (which are expected to be in the range 0 - 255), + * returning a 16 bit number combining either side of the , as the MSB and + * LSB. + */ u_short ipf_ftp_atoi(ptr) char **ptr; { @@ -75,42 +110,38 @@ tcphdr_t *tcp; ap_session_t *aps; nat_t *nat; { - register u_long sum1, sum2, sumd; + register u_long sum1, sum2; char newbuf[IPF_MAXPORTLEN+1]; - char portbuf[IPF_MAXPORTLEN+1], *s, c; - int ch = 0, off = (ip->ip_hl << 2) + (tcp->th_off << 2), len; + char portbuf[IPF_MAXPORTLEN+1], *s; + int ch = 0, off = (ip->ip_hl << 2) + (tcp->th_off << 2); u_int a1, a2, a3, a4; u_short a5, a6; - int olen, dlen, nlen, inc = 0, blen; + int olen, dlen, nlen = 0, inc = 0; tcphdr_t tcph, *tcp2 = &tcph; void *savep; nat_t *ipn; struct in_addr swip; + mb_t *m = *(mb_t **)fin->fin_mp; + #if SOLARIS - mblk_t *m1, *m = *(mblk_t **)fin->fin_mp; + mb_t *m1; - dlen = m->b_wptr - m->b_rptr - off; - blen = m->b_datap->db_lim - m->b_datap->db_base; + /* skip any leading M_PROTOs */ + while(m && (MTYPE(m) != M_DATA)) + m = m->b_cont; + PANIC((!m),("ippr_ftp_out: no M_DATA")); + + dlen = msgdsize(m) - off; bzero(portbuf, sizeof(portbuf)); - copyout_mblk(m, off, portbuf, MIN(sizeof(portbuf), dlen)); + copyout_mblk(m, off, MIN(sizeof(portbuf), dlen), portbuf); #else - struct mbuf *m1, *m = *(struct mbuf **)fin->fin_mp; - - dlen = m->m_len - off; -# if BSD >= 199306 - blen = (MLEN - m->m_len) - (m->m_data - m->m_dat); -# else - blen = (MLEN - m->m_len) - m->m_off; -# endif - if (blen < 0) - panic("blen < 0 - size of mblk/mbuf wrong"); + dlen = mbufchainlen(m) - off; bzero(portbuf, sizeof(portbuf)); m_copydata(m, off, MIN(sizeof(portbuf), dlen), portbuf); #endif portbuf[IPF_MAXPORTLEN] = '\0'; - len = MIN(32, dlen); - if ((len < IPF_MINPORTLEN) || strncmp(portbuf, "PORT ", 5)) + if ((dlen < IPF_MINPORTLEN) || strncmp(portbuf, "PORT ", 5)) goto adjust_seqack; /* @@ -149,30 +180,48 @@ nat_t *nat; a1, a2, a3, a4, a5, a6); nlen = strlen(newbuf); inc = nlen - olen; - if (tcp->th_seq > aps->aps_after) { - aps->aps_after = ntohl(tcp->th_seq) + dlen; - aps->aps_seqoff += inc; - } #if SOLARIS - if (inc && dlen) - if ((inc < 0) || (blen >= dlen)) { - bcopy(m->b_rptr + off, - m->b_rptr + off + aps->aps_seqoff, dlen); - } for (m1 = m; m1->b_cont; m1 = m1->b_cont) ; - m1->b_wptr += inc; - copyin_mblk(m, off, newbuf, strlen(newbuf)); + if (inc > 0) { + mblk_t *nm; + + /* alloc enough to keep same trailer space for lower driver */ + nm = allocb(nlen + m1->b_datap->db_lim - m1->b_wptr, BPRI_MED); + PANIC((!nm),("ippr_ftp_out: allocb failed")); + + nm->b_band = m1->b_band; + nm->b_wptr += nlen; + + m1->b_wptr -= olen; + PANIC((m1->b_wptr < m1->b_rptr),("ippr_ftp_out: cannot handle fragmented data block")); + + linkb(m1, nm); + } else { + m1->b_wptr += inc; + } + copyin_mblk(m, off, nlen, newbuf); #else - if (inc && dlen) - if ((inc < 0) || (blen >= dlen)) { - bcopy((char *)ip + off, - (char *)ip + off + aps->aps_seqoff, dlen); - } - m->m_len += inc; + if (inc < 0) + m_adj(m, inc); + /* the mbuf chain will be extended if necessary by m_copyback() */ m_copyback(m, off, nlen, newbuf); #endif - ip->ip_len += inc; + if (inc) { +#if SOLARIS || defined(__sgi) + sum1 = ip->ip_len; + sum2 = ip->ip_len + inc; + + /* Because ~1 == -2, We really need ~1 == -1 */ + if (sum1 > sum2) + sum2--; + sum2 -= sum1; + sum2 = (sum2 & 0xffff) + (sum2 >> 16); + + fix_outcksum(&ip->ip_sum, sum2); +#endif + ip->ip_len += inc; + } ch = 1; /* @@ -181,24 +230,40 @@ nat_t *nat; */ savep = fin->fin_dp; fin->fin_dp = (char *)tcp2; + bzero((char *)tcp2, sizeof(*tcp2)); tcp2->th_sport = htons(a5 << 8 | a6); tcp2->th_dport = htons(20); swip = ip->ip_src; ip->ip_src = nat->nat_inip; if ((ipn = nat_new(nat->nat_ptr, ip, fin, IPN_TCP, NAT_OUTBOUND))) ipn->nat_age = fr_defnatage; + (void) fr_addstate(ip, fin, FR_INQUE|FR_PASS|FR_QUICK|FR_KEEPSTATE); ip->ip_src = swip; fin->fin_dp = (char *)savep; adjust_seqack: if (tcp->th_dport == aps->aps_dport) { sum2 = (u_long)ntohl(tcp->th_seq); - if (aps->aps_seqoff && (sum2 > aps->aps_after)) { - sum1 = (u_long)aps->aps_seqoff; - tcp->th_seq = htonl(sum2 + sum1); - ch = 1; + off = aps->aps_sel; + if ((aps->aps_after[!off] > aps->aps_after[off]) && + (sum2 > aps->aps_after[!off])) { + off = aps->aps_sel = !off; /* switch to other set */ + } + if (aps->aps_seqoff[off]) { + sum1 = (u_long)aps->aps_after[off] - + aps->aps_seqoff[off]; + if (sum2 > sum1) { + sum1 = (u_long)aps->aps_seqoff[off]; + sum2 += sum1; + tcp->th_seq = htonl(sum2); + ch = 1; + } } - } + if (inc && (sum2 > aps->aps_after[!off])) { + aps->aps_after[!off] = sum2 + nlen - 1; + aps->aps_seqoff[!off] = aps->aps_seqoff[off] + inc; + } + } return ch ? 2 : 0; } |