diff options
Diffstat (limited to 'ucgi/ucgicommon.c')
| -rw-r--r-- | ucgi/ucgicommon.c | 221 |
1 files changed, 221 insertions, 0 deletions
diff --git a/ucgi/ucgicommon.c b/ucgi/ucgicommon.c new file mode 100644 index 0000000..c3eb4b3 --- /dev/null +++ b/ucgi/ucgicommon.c @@ -0,0 +1,221 @@ +/* + * Copyright 1996-2013,2016 Ian Jackson <ijackson@chiark.greenend.org.uk> + * Copyright 1998 David Damerell <damerell@chiark.greenend.org.uk> + * Copyright 1999,2003 + * Chancellor Masters and Scholars of the University of Cambridge + * Copyright 2010 Tony Finch <fanf@dotat.at> + * Copyright 2013,2016 Mark Wooding <mdw@distorted.org.uk> + * + * This is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 3 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with userv-utils; if not, see http://www.gnu.org/licenses/. + */ + +#include <assert.h> +#include <ctype.h> +#include <stdarg.h> +#include <stdio.h> +#include <string.h> +#include <errno.h> + +#include <unistd.h> + +#include "ucgi.h" + +int debugmode= 0; + +static void outerror(void) { + perror("stdout"); + exit(debugmode ? 0 : -1); +} + +void syserror(const char *m) { + if (printf("Content-Type: text/plain\n" + "Status: 500\n\n" + "ucgi: system call error:\n" + "%s: %s\n", + m,strerror(errno))==EOF || fflush(stdout)) outerror(); + exit(0); +} + +void error(const char *m, int st) { + if (printf("Content-Type: text/plain\n" + "Status: %d\n\n" + "ucgi: error:\n" + "%s\n", + st, m)==EOF || fflush(stdout)) outerror(); + exit(0); +} + +void *xmalloc(size_t sz) { + void *r; + + r= malloc(sz); + if (!r) syserror("malloc failed"); + return r; +} + +void *xrealloc(void *ptr, size_t sz) { + void *r; + + r= realloc(ptr,sz); + if (!r) syserror("realloc failed"); + return r; +} + +void xsetenv(const char *en, const char *ev, int overwrite) { + if (setenv(en,ev,overwrite)) syserror("setenv"); +} + +const char **load_filters(unsigned flags, const char *first, ...) { + va_list ap; + const char *name, *p, *q, **v; + char *pp; + size_t l, n, sz; + FILE *fp; + char buf[MAX_ENVVAR_NAME]; + + D( if (debugmode) printf(";; load_filters...\n"); ) + va_start(ap, first); + for (name= first; name; name= va_arg(ap, const char *)) { + fp= fopen(name, "r"); if (fp) goto opened; + D( if (debugmode) + printf(";; file `%s': %s\n", name, strerror(errno)); ) + if (errno != ENOENT) syserror("failed to open environment filters"); + } + va_end(ap); + if (flags & LOADF_MUST) syserror("failed to open environment filters"); + D( if (debugmode) printf(";; using default filters\n"); ) + return 0; + +opened: + va_end(ap); + D( if (debugmode) printf(";; file `%s': OK\n", name); ) + + n= 0; sz= 128; v= xmalloc(sz * sizeof(*v)); + for (;;) { + if (!fgets(buf, sizeof(buf), fp)) break; + l= strlen(buf); + if (buf[l - 1] == '\n') buf[--l]= 0; + if (l + 1 == sizeof(buf)) + error("line too long in environment filter file", 500); + p= buf; q= p + l; + while (isspace((unsigned char)*p)) p++; + while (q > p && isspace((unsigned char)q[-1])) q--; + if (*p == '#' || p == q) continue; + l= q - p; + pp= xmalloc(l + 1); + memcpy(pp, p, l); + pp[l]= 0; + v[n++]= pp; + D( if (debugmode) printf(";; filter: `%s'\n", pp); ) + if (n >= sz) { + sz *= 2; + v= xrealloc(v, sz * sizeof(*v)); + } + } + if (ferror(fp)) syserror("failed to read environment filters"); + fclose(fp); + return v; +} + +static int envvar_match(unsigned flags, const char *en, + const char *const *patv, + const char *const *defaults, + const char **ev) { + const char *const *patp; + const char *q, *pat; + int acceptp; + int rc; + + if (!patv) { patv= defaults; defaults= 0; } + for (patp= patv; (pat= *patp); patp++) { + q= en; + acceptp= 1; + if (*pat == '!' && (flags & FILTF_WILDCARD)) { acceptp= 0; pat++; } + else if (*pat == '?') { + if (strcmp(pat + 1, "DEFAULTS") == 0) { + assert(defaults); + rc= envvar_match(flags, en, defaults, 0, ev); + if (rc) return rc; + } else + error("unknown pattern directive", 500); + continue; + } + + for (;;) { + if (!*pat) { + if (*q != '=') { + D( if (debugmode) + printf(";; mismatch `%s' (prefix)\n", *patp); ) + break; + } + D( if (debugmode) printf(";; matched pattern `%s'\n", *patp); ) + goto match; + } else if (*pat == '*' && (flags & FILTF_WILDCARD)) { + q = strchr(q, '='); + if (!q) { + D( if (debugmode) + printf(";; mismatch `%s' (discard: no `=')\n", *patp); ) + return -1; + } + D( if (debugmode) + printf(";; wildcard match for `%s'\n", *patp); ) + goto match; + } else { + if (*pat++ != *q++) { + D( if (debugmode) printf(";; mismatch `%s'\n", *patp); ) + break; + } + } + } + } + return 0; + +match: + if (!acceptp) return -1; + *ev= q + 1; + return +1; +} + +void filter_environment(unsigned flags, const char *prefix_in, + const char *const *patv, + const char *const *defaults, + void (*foundone)(const char *fulln, + const char *en, const char *ev, + void *p), + void *p) { + char *const *ep; + const char *en, *ev; + char enbuf[MAX_ENVVAR_NAME]; + size_t n, pn = strlen(prefix_in); + + D( if (debugmode) printf(";; filter_environment...\n"); ) + for (ep= environ; (en= *ep); ep++) { + D( if (debugmode) printf(";; consider env-var `%s'\n", en); ) + if (strncmp(en, prefix_in, pn) != 0 || !en[pn]) { + D( if (debugmode) printf(";; doesn't match prefix\n"); ) + continue; + } + if (envvar_match(flags, en + pn, patv, defaults, &ev) > 0) { + n= strcspn(en, "="); + if (n >= sizeof(enbuf)) + error("environment variable name too long", 500); + memcpy(enbuf, en, n); + enbuf[n]= 0; + D( if (debugmode) + printf(";; full = `%s'; tail = `%s'; value = `%s'\n", + enbuf, enbuf + pn, ev); ) + foundone(enbuf, enbuf + pn, ev, p); + } + } +} |