/** Render a stanza object to text. * This function renders a given stanza object, along with its * children, to text. The text is returned in an allocated, * null-terminated buffer. It starts by allocating a 1024 byte buffer * and reallocates more memory if that is not large enough. * * @param stanza a Strophe stanza object * @param buf a reference to a string pointer * @param buflen a reference to a size_t * * @return 0 on success (XMPP_EOK), and a number less than 0 on failure * (XMPP_EMEM, XMPP_EINVOP) * * @ingroup Stanza */ int xmpp_stanza_to_text(xmpp_stanza_t *stanza, char ** const buf, size_t * const buflen) { char *buffer, *tmp; size_t length; int ret; /* allocate a default sized buffer and attempt to render */ length = 1024; buffer = xmpp_alloc(stanza->ctx, length); if (!buffer) { *buf = NULL; *buflen = 0; return XMPP_EMEM; } ret = _render_stanza_recursive(stanza, buffer, length); if (ret < 0) return ret; if ((size_t)ret > length - 1) { tmp = xmpp_realloc(stanza->ctx, buffer, ret + 1); if (!tmp) { xmpp_free(stanza->ctx, buffer); *buf = NULL; *buflen = 0; return XMPP_EMEM; } length = ret + 1; buffer = tmp; ret = _render_stanza_recursive(stanza, buffer, length); if ((size_t)ret > length - 1) return XMPP_EMEM; } buffer[length - 1] = 0; *buf = buffer; *buflen = ret; return XMPP_EOK; }
/* always returns number of bytes written or that would have been * written if the buffer was large enough * return values < 0 indicate some error occurred, * and return values > buflen indicate buffer was not large enough */ static int _render_stanza_recursive(xmpp_stanza_t *stanza, char * const buf, size_t const buflen) { char *ptr = buf; size_t left = buflen; int ret, written; xmpp_stanza_t *child; hash_iterator_t *iter; const char *key; char *tmp; written = 0; if (stanza->type == XMPP_STANZA_UNKNOWN) return XMPP_EINVOP; if (stanza->type == XMPP_STANZA_TEXT) { if (!stanza->data) return XMPP_EINVOP; tmp = _escape_xml(stanza->ctx, stanza->data); if (tmp == NULL) return XMPP_EMEM; ret = xmpp_snprintf(ptr, left, "%s", tmp); xmpp_free(stanza->ctx, tmp); if (ret < 0) return XMPP_EMEM; _render_update(&written, buflen, ret, &left, &ptr); } else { /* stanza->type == XMPP_STANZA_TAG */ if (!stanza->data) return XMPP_EINVOP; /* write beginning of tag and attributes */ ret = xmpp_snprintf(ptr, left, "<%s", stanza->data); if (ret < 0) return XMPP_EMEM; _render_update(&written, buflen, ret, &left, &ptr); if (stanza->attributes && hash_num_keys(stanza->attributes) > 0) { iter = hash_iter_new(stanza->attributes); while ((key = hash_iter_next(iter))) { if (!strcmp(key, "xmlns")) { /* don't output namespace if parent stanza is the same */ if (stanza->parent && stanza->parent->attributes && hash_get(stanza->parent->attributes, key) && !strcmp((char*)hash_get(stanza->attributes, key), (char*)hash_get(stanza->parent->attributes, key))) continue; /* or if this is the stream namespace */ if (!stanza->parent && !strcmp((char*)hash_get(stanza->attributes, key), XMPP_NS_CLIENT)) continue; } tmp = _escape_xml(stanza->ctx, (char *)hash_get(stanza->attributes, key)); if (tmp == NULL) return XMPP_EMEM; ret = xmpp_snprintf(ptr, left, " %s=\"%s\"", key, tmp); xmpp_free(stanza->ctx, tmp); if (ret < 0) return XMPP_EMEM; _render_update(&written, buflen, ret, &left, &ptr); } hash_iter_release(iter); } if (!stanza->children) { /* write end if singleton tag */ ret = xmpp_snprintf(ptr, left, "/>"); if (ret < 0) return XMPP_EMEM; _render_update(&written, buflen, ret, &left, &ptr); } else { /* this stanza has child stanzas */ /* write end of start tag */ ret = xmpp_snprintf(ptr, left, ">"); if (ret < 0) return XMPP_EMEM; _render_update(&written, buflen, ret, &left, &ptr); /* iterate and recurse over child stanzas */ child = stanza->children; while (child) { ret = _render_stanza_recursive(child, ptr, left); if (ret < 0) return ret; _render_update(&written, buflen, ret, &left, &ptr); child = child->next; } /* write end tag */ ret = xmpp_snprintf(ptr, left, "</%s>", stanza->data); if (ret < 0) return XMPP_EMEM; _render_update(&written, buflen, ret, &left, &ptr); } } return written; }
/* always returns number of bytes written or that would have been * written if the buffer was large enough * return values < 0 indicate some error occured, * and return values > buflen indicate buffer was not large enough */ static int _render_stanza_recursive(xmpp_stanza_t *stanza, char * const buf, size_t const buflen) { char *ptr = buf; size_t left = buflen; int ret, written; xmpp_stanza_t *child; hash_iterator_t *iter; const char *key; assert(stanza); written = 0; if (stanza->type == XMPP_STANZA_UNKNOWN) return XMPP_EINVOP; if (stanza->type == XMPP_STANZA_TEXT) { if (!stanza->data) return XMPP_EINVOP; assert(stanza->data); ret = xmpp_snprintf(ptr, left, "%s", stanza->data); if (ret < 0) return XMPP_EMEM; _render_update(&written, buflen, ret, &left, &ptr); } else { /* stanza->type == XMPP_STANZA_TAG */ if (!stanza->data) return XMPP_EINVOP; /* write begining of tag and attributes */ assert(stanza->data); ret = xmpp_snprintf(ptr, left, "<%s", stanza->data); if (ret < 0) return XMPP_EMEM; _render_update(&written, buflen, ret, &left, &ptr); if (stanza->attributes && hash_num_keys(stanza->attributes) > 0) { iter = hash_iter_new(stanza->attributes); while ((key = hash_iter_next(iter))) { assert(hash_get(stanza->attributes, key)); ret = xmpp_snprintf(ptr, left, " %s=\"%s\"", key, (char *)hash_get(stanza->attributes, key)); if (ret < 0) return XMPP_EMEM; _render_update(&written, buflen, ret, &left, &ptr); } hash_iter_release(iter); } if (!stanza->children) { /* write end if singleton tag */ ret = xmpp_snprintf(ptr, left, "/>"); if (ret < 0) return XMPP_EMEM; _render_update(&written, buflen, ret, &left, &ptr); } else { /* this stanza has child stanzas */ /* write end of start tag */ ret = xmpp_snprintf(ptr, left, ">"); if (ret < 0) return XMPP_EMEM; _render_update(&written, buflen, ret, &left, &ptr); /* iterate and recurse over child stanzas */ child = stanza->children; while (child) { ret = _render_stanza_recursive(child, ptr, left); if (ret < 0) return ret; _render_update(&written, buflen, ret, &left, &ptr); child = child->next; } /* write end tag */ assert(stanza->data); ret = xmpp_snprintf(ptr, left, "</%s>", stanza->data); if (ret < 0) return XMPP_EMEM; _render_update(&written, buflen, ret, &left, &ptr); } } return written; }