/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/ /*** This file is part of systemd. Copyright 2013 Lennart Poettering systemd is free software; you can redistribute it and/or modify it under the terms of the GNU Lesser General Public License as published by the Free Software Foundation; either version 2.1 of the License, or (at your option) any later version. systemd 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 Lesser General Public License for more details. You should have received a copy of the GNU Lesser General Public License along with systemd; If not, see <http://www.gnu.org/licenses/>. ***/ #include <string.h> #include "util.h" #include "xml.h" enum { STATE_TEXT, STATE_TAG, STATE_ATTRIBUTE, }; /* We don't actually do real XML here. We only read a simplistic * subset, that is a bit less strict that XML and lacks all the more * complex features, like entities, or namespaces. However, we do * support some HTML5-like simplifications */ int xml_tokenize(const char **p, char **name, void **state) { const char *c, *e, *b; char *ret; int t; assert(p); assert(*p); assert(name); assert(state); t = PTR_TO_INT(*state); c = *p; for (;;) { if (*c == 0) return XML_END; switch (t) { case STATE_TEXT: { int x; e = strchrnul(c, '<'); if (e > c) { /* More text... */ ret = strndup(c, e - c); if (!ret) return -ENOMEM; *name = ret; *p = e; *state = INT_TO_PTR(STATE_TEXT); return XML_TEXT; } assert(*e == '<'); b = c + 1; if (startswith(b, "!--")) { /* A comment */ e = strstr(b + 3, "-->"); if (!e) return -EINVAL; c = e + 3; continue; } if (*b == '?') { /* Processing instruction */ e = strstr(b + 1, "?>"); if (!e) return -EINVAL; c = e + 2; continue; } if (*b == '!') { /* DTD */ e = strchr(b + 1, '>'); if (!e) return -EINVAL; c = e + 1; continue; } if (*b == '/') { /* A closing tag */ x = XML_TAG_CLOSE; b++; } else x = XML_TAG_OPEN; e = strpbrk(b, WHITESPACE "/>"); if (!e) return -EINVAL; ret = strndup(b, e - b); if (!ret) return -ENOMEM; *name = ret; *p = e; *state = INT_TO_PTR(STATE_TAG); return x; } case STATE_TAG: b = c + strspn(c, WHITESPACE); if (*b == 0) return -EINVAL; e = b + strcspn(b, WHITESPACE "=/>"); if (e > b) { /* An attribute */ ret = strndup(b, e - b); if (!ret) return -ENOMEM; *name = ret; *p = e; *state = INT_TO_PTR(STATE_ATTRIBUTE); return XML_ATTRIBUTE_NAME; } if (startswith(b, "/>")) { /* An empty tag */ *name = NULL; /* For empty tags we return a NULL name, the caller must be prepared for that */ *p = b + 2; *state = INT_TO_PTR(STATE_TEXT); return XML_TAG_CLOSE_EMPTY; } if (*b != '>') return -EINVAL; c = b + 1; t = STATE_TEXT; continue; case STATE_ATTRIBUTE: if (*c == '=') { c++; if (*c == '\'' || *c == '\"') { /* Tag with a quoted value */ e = strchr(c+1, *c); if (!e) return -EINVAL; ret = strndup(c+1, e - c - 1); if (!ret) return -ENOMEM; *name = ret; *p = e + 1; *state = INT_TO_PTR(STATE_TAG); return XML_ATTRIBUTE_VALUE; } /* Tag with a value without quotes */ b = strpbrk(c, WHITESPACE ">"); if (!b) b = c; ret = strndup(c, b - c); if (!ret) return -ENOMEM; *name = ret; *p = b; *state = INT_TO_PTR(STATE_TAG); return XML_ATTRIBUTE_VALUE; } t = STATE_TAG; continue; } } assert_not_reached("Bad state"); }