ref: faa625a1d5ab47ac0438b2cea5b2bde1ea747b8b
dir: /sys/src/boot/pc/pxe.c/
#include <u.h> #include "fns.h" enum { Tftp_READ = 1, Tftp_WRITE = 2, Tftp_DATA = 3, Tftp_ACK = 4, Tftp_ERROR = 5, Tftp_OACK = 6, TftpPort = 69, Segsize = 512, Maxpath = 64, }; typedef uchar IP4[4]; typedef struct Tftp Tftp; typedef struct Dhcp Dhcp; struct Tftp { IP4 sip; IP4 dip; IP4 gip; int sport; int dport; char *rp; char *ep; int seq; int eof; char pkt[2+2+Segsize]; char nul; }; struct Dhcp { uchar opcode; uchar hardware; uchar hardlen; uchar gatehops; uchar ident[4]; uchar seconds[2]; uchar flags[2]; uchar cip[4]; uchar yip[4]; uchar sip[4]; uchar gip[4]; uchar mac[16]; char sname[64]; char bootfile[128]; }; int pxeinit(void); int pxecall(int op, void *buf); static void* unfar(ulong seg, ulong off) { return (void*)((off & 0xFFFF) + (seg & 0xFFFF)*16); } static void puts(void *x, ushort v) { uchar *p = x; p[1] = (v>>8) & 0xFF; p[0] = v & 0xFF; } static ushort gets(void *x) { uchar *p = x; return p[1]<<8 | p[0]; } static void hnputs(void *x, ushort v) { uchar *p = x; p[0] = (v>>8) & 0xFF; p[1] = v & 0xFF; } static ushort nhgets(void *x) { uchar *p = x; return p[0]<<8 | p[1]; } static void moveip(IP4 d, IP4 s) { memmove(d, s, sizeof(d)); } void unload(void) { struct { uchar status[2]; uchar junk[10]; } buf; static uchar shutdown[] = { 0x05, 0x070, 0x02, 0 }; uchar *o; for(o = shutdown; *o; o++){ memset(&buf, 0, sizeof(buf)); if(pxecall(*o, &buf)) break; } } static int getip(IP4 yip, IP4 sip, IP4 gip, char mac[16]) { struct { uchar status[2]; uchar pkttype[2]; uchar bufsize[2]; uchar off[2]; uchar seg[2]; uchar lim[2]; } buf; int i, r; Dhcp *p; memset(&buf, 0, sizeof(buf)); puts(buf.pkttype, 3); if(r = pxecall(0x71, &buf)) return -r; if((p = unfar(gets(buf.seg), gets(buf.off))) == 0) return -1; moveip(yip, p->yip); moveip(sip, p->sip); moveip(gip, p->gip); mac[12] = 0; for(i=0; i<6; i++){ mac[i*2] = hex[p->mac[i]>>4]; mac[i*2+1] = hex[p->mac[i]&15]; } return 0; } static int udpopen(IP4 sip) { struct { uchar status[2]; uchar sip[4]; } buf; puts(buf.status, 0); moveip(buf.sip, sip); return pxecall(0x30, &buf); } static int udpclose(void) { uchar status[2]; puts(status, 0); return pxecall(0x31, status); } static int udpread(IP4 sip, IP4 dip, int *sport, int dport, int *len, void *data) { struct { uchar status[2]; uchar sip[4]; uchar dip[4]; uchar sport[2]; uchar dport[2]; uchar len[2]; uchar off[2]; uchar seg[2]; } buf; int r; puts(buf.status, 0); moveip(buf.sip, sip); moveip(buf.dip, dip); hnputs(buf.sport, *sport); hnputs(buf.dport, dport); puts(buf.len, *len); puts(buf.off, (long)data); puts(buf.seg, 0); if(r = pxecall(0x32, &buf)) return r; moveip(sip, buf.sip); *sport = nhgets(buf.sport); *len = gets(buf.len); return 0; } static int udpwrite(IP4 ip, IP4 gw, int sport, int dport, int len, void *data) { struct { uchar status[2]; uchar ip[4]; uchar gw[4]; uchar sport[2]; uchar dport[2]; uchar len[2]; uchar off[2]; uchar seg[2]; } buf; puts(buf.status, 0); moveip(buf.ip, ip); moveip(buf.gw, gw); hnputs(buf.sport, sport); hnputs(buf.dport, dport); puts(buf.len, len); puts(buf.off, (long)data); puts(buf.seg, 0); return pxecall(0x33, &buf); } int read(void *f, void *data, int len) { Tftp *t = f; int seq, n; while(!t->eof && t->rp >= t->ep){ for(;;){ n = sizeof(t->pkt); if(udpread(t->dip, t->sip, &t->dport, t->sport, &n, t->pkt)) continue; if(n >= 4) break; } switch(nhgets(t->pkt)){ case Tftp_DATA: seq = nhgets(t->pkt+2); if(seq > t->seq){ putc('?'); continue; } hnputs(t->pkt, Tftp_ACK); while(udpwrite(t->dip, t->gip, t->sport, t->dport, 4, t->pkt)) putc('!'); if(seq < t->seq){ putc('@'); continue; } t->seq = seq+1; n -= 4; t->rp = t->pkt + 4; t->ep = t->rp + n; t->eof = n < Segsize; break; case Tftp_ERROR: print(t->pkt+4); print("\n"); default: t->eof = 1; return -1; } break; } n = t->ep - t->rp; if(len > n) len = n; memmove(data, t->rp, len); t->rp += len; return len; } void close(void *f) { Tftp *t = f; t->eof = 1; udpclose(); } static int tftpopen(Tftp *t, char *path, IP4 sip, IP4 dip, IP4 gip) { static ushort xport = 6666; int r, n; char *p; moveip(t->sip, sip); moveip(t->gip, gip); memset(t->dip, 0, sizeof(t->dip)); t->sport = xport++; t->dport = 0; t->rp = t->ep = 0; t->seq = 1; t->eof = 0; t->nul = 0; if(r = udpopen(t->sip)) return r; p = t->pkt; hnputs(p, Tftp_READ); p += 2; n = strlen(path)+1; memmove(p, path, n); p += n; memmove(p, "octet", 6); p += 6; n = p - t->pkt; for(;;){ if(r = udpwrite(dip, t->gip, t->sport, TftpPort, n, t->pkt)) break; if(r = read(t, 0, 0)) break; return 0; } close(t); return r; } void start(void *) { char mac[16], path[Maxpath], *kern; IP4 yip, sip, gip; void *f; Tftp t; if(pxeinit()){ print("pxe init\n"); halt(); } if(getip(yip, sip, gip, mac)){ print("bad dhcp\n"); halt(); } memmove(path, "/cfg/pxe/", 9); memmove(path+9, mac, 13); if(tftpopen(f = &t, path, yip, sip, gip)) if(tftpopen(f, "/cfg/pxe/default", yip, sip, gip)){ print("no config\n"); f = 0; } for(;;){ kern = configure(f, path); f = 0; if(tftpopen(&t, kern, yip, sip, gip)){ print("not found\n"); continue; } print(bootkern(&t)); print("\n"); } }