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1.1 root 1: /* pathalias -- by steve bellovin, as told to peter honeyman */
2: #ifndef lint
3: static char *sccsid = "@(#)addlink.c 8.1 (down!honey) 86/01/19";
4: #endif lint
5:
6: #include "def.h"
7:
8: static link *Trace[NTRACE];
9: static int Tracecount;
10:
11: link *
12: addlink(from, to, cost, netchar, netdir)
13: node *from;
14: register node *to;
15: Cost cost;
16: char netchar;
17: char netdir;
18: {
19: register link *l, *prev = 0;
20:
21: if (Tflag)
22: ltrace(from, to, cost, netchar, netdir);
23: /* maintain uniqueness for dead links (only) */
24: for (l = from->n_link; l && l->l_flag & LDEAD; l = l->l_next) {
25: if (to == l->l_to) {
26: /* what the hell, use cheaper cost */
27: if (cost < l->l_cost) {
28: l->l_cost = cost;
29: netbits(l, netchar, netdir);
30: }
31: return(l);
32: }
33: prev = l;
34: }
35:
36: /* allocate and link in the new link struct */
37: l = newlink();
38: if (cost != INF) /* ignore back links */
39: Lcount++;
40: if (prev) {
41: l->l_next = prev->l_next;
42: prev->l_next = l;
43: } else {
44: l->l_next = from->n_link;
45: from->n_link = l;
46: }
47:
48: l->l_to = to;
49: l->l_cost = cost;
50: if (netchar == 0) {
51: netchar = DEFNET;
52: netdir = DEFDIR;
53: }
54: netbits(l, netchar, netdir);
55:
56: return(l);
57: }
58:
59: link *
60: addgateway(from, to, cost, netchar, netdir)
61: node *from;
62: node *to;
63: Cost cost;
64: char netchar;
65: char netdir;
66: {
67: register link *l;
68:
69: l = addlink(from, to, cost, netchar, netdir);
70: l->l_flag |= LGATEWAY;
71: return(l);
72: }
73:
74: deadlink(s)
75: char *s;
76: {
77: char *t, c;
78: link *l;
79:
80: t = index(s, '!');
81: if (t) {
82: c = *t;
83: *t = 0;
84: l = addlink(addnode(s), addnode(t + 1), INF / 2, c, DEFDIR);
85: l->l_flag |= LDEAD;
86: } else
87: addnode(s)->n_flag |= NDEAD;
88: }
89:
90: netbits(l, netchar, netdir)
91: link *l;
92: char netchar, netdir;
93: {
94: char *nptr;
95:
96: if ((nptr = index(Netchars, netchar)) == 0) {
97: fprintf(stderr, "%s: unknown network operator: %c\n",
98: ProgName, netchar);
99: badmagic(1);
100: }
101: l->l_flag &= ~(LNETCHARS|LDIR);
102: l->l_flag |= (nptr - Netchars) | dirbits(netdir);
103: }
104:
105: tracelink(arg)
106: char *arg;
107: {
108: char *bang;
109: link *l;
110:
111: if (Tracecount >= NTRACE)
112: return(-1);
113: l = newlink();
114: bang = index(arg, '!');
115: if (bang) {
116: *bang = 0;
117: l->l_to = addnode(bang+1);
118: } else
119: l->l_to = 0;
120:
121: l->l_from = (link *) addnode(arg);
122: Trace[Tracecount++] = l;
123: return(0);
124: }
125:
126: STATIC
127: ltrace(from, to, cost, netchar, netdir)
128: node *from, *to;
129: Cost cost;
130: char netchar;
131: char netdir;
132: {
133: link *l;
134: int i;
135:
136: for (i = 0; i < Tracecount; i++) {
137: l = Trace[i];
138: /* overkill -- you asked for it! */
139: if ((l->l_to == 0
140: && (from == (node *) l->l_from || to == (node *) l->l_from))
141: || (from == (node *) l->l_from && to == l->l_to)
142: || (to == (node *) l->l_from && from == l->l_to)) {
143: ltrprint(from, to, cost, netchar, netdir);
144: return;
145: }
146: }
147: }
148:
149: /* print a trace item */
150: STATIC
151: ltrprint(from, to, cost, netchar, netdir)
152: node *from, *to;
153: Cost cost;
154: char netchar;
155: char netdir;
156: {
157: char buf[256], *bptr = buf;
158:
159: strcpy(bptr, from->n_name);
160: bptr += strlen(bptr);
161: *bptr++ = ' ';
162: if (netdir == LRIGHT) /* @% */
163: *bptr++ = netchar;
164: strcpy(bptr, to->n_name);
165: bptr += strlen(bptr);
166: if (netdir == LLEFT) /* !: */
167: *bptr++ = netchar;
168: sprintf(bptr, "(%ld)", cost);
169: yyerror(buf);
170: }
171:
172: atrace(n1, n2)
173: node *n1, *n2;
174: {
175: link *l;
176: int i;
177: char buf[256];
178:
179: for (i = 0; i < Tracecount; i++) {
180: l = Trace[i];
181: if (l->l_to == 0 && ((node *) l->l_from == n1 || (node *) l->l_from == n2)) {
182: sprintf(buf, "%s = %s", n1->n_name, n2->n_name);
183: yyerror(buf);
184: return;
185: }
186: }
187: }
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