<!-- Kamailio Pull Request Template -->
<!--
IMPORTANT:
- for detailed contributing guidelines, read:
https://github.com/kamailio/kamailio/blob/master/.github/CONTRIBUTING.md
- pull requests must be done to master branch, unless they are backports
of fixes from master branch to a stable branch
- backports to stable branches must be done with 'git cherry-pick -x
...'
- code is contributed under BSD for core and main components (tm, sl, auth,
tls)
- code is contributed GPLv2 or a compatible license for the other components
- GPL code is contributed with OpenSSL licensing exception
-->
#### Pre-Submission Checklist
<!-- Go over all points below, and after creating the PR, tick all the
checkboxes that apply -->
<!-- All points should be verified, otherwise, read the CONTRIBUTING
guidelines from above-->
<!-- If you're unsure about any of these, don't hesitate to ask on
sr-dev mailing list -->
- [X] Commit message has the format required by CONTRIBUTING guide
- [X] Commits are split per component (core, individual modules, libs, utils,
...)
- [X] Each component has a single commit (if not, squash them into one commit)
- [ ] No commits to README files for modules (changes must be done to docbook
files
in `doc/` subfolder, the README file is autogenerated)
#### Type Of Change
- [ ] Small bug fix (non-breaking change which fixes an issue)
- [X] New feature (non-breaking change which adds new functionality)
- [ ] Breaking change (fix or feature that would change existing functionality)
#### Checklist:
<!-- Go over all points below, and after creating the PR, tick the
checkboxes that apply -->
- [ ] PR should be backported to stable branches
- [X] Tested changes locally
- [ ] Related to issue #XXXX (replace XXXX with an open issue number)
#### Description
<!-- Describe your changes in detail -->
This change should allow a small optimization/convenience improvement when
building a combined string for XAVP value.
Consider the `xavp_example-1.c`. It builds a semicolon-separated string of
parameters out of some data and makes XAVP from this combined string. It has to
build the string entirely before passing it to `xavp_add_value()`. It either
needs to use some fixed-length pad buffer or has to allocate/deallocate a
temporary PKG buffer to build the string.
This change allows `SR_XTYPE_STR` values with `NULL` data (but with non-zero
length) into `xavp_add_value()`. In that case `xavp_add_value()` will create a
shared memory buffer for the string, but wouldn't try to copy string data
into the buffer, leaving it uninitialized. The string content should be filled
in-place later through the returned `sr_xavp_t *`. This allows simpler
`xavp_example-2.c`.
<details>
<summary>xavp_example-1.c</summary>
```c
struct some_third_party_item
{
const char *key;
const char *value;
size_t key_sz, value_sz;
};
int add_items_xavp1()
{
struct some_third_party_item **list = some_third_party_func();
str key = STR_STATIC_INIT("items");
sr_xval_t value = {.type = SR_XTYPE_STR, .v = {.s = STR_NULL}};
/* Compute total size of the combined string */
for(int i = 0; list[i]; ++i) {
value.v.s.len += (i != 0); /* ; */
value.v.s.len += (int)list[i]->key_sz;
value.v.s.len += 1; /* = */
value.v.s.len += (int)list[i]->value_sz;
}
/* Allocate temporary buffer */
if((value.v.s.s = pkg_malloc(value.v.s.len)) == NULL) {
LM_ERR("couldn't allocate string value");
return -1;
}
/* Build the string in the temporary buffer */
char *dest = value.v.s.s;
for(int i = 0; list[i]; ++i) {
if(i != 0) {
*dest++ = ';';
}
memcpy(dest, list[i]->key, list[i]->key_sz);
dest += list[i]->key_sz;
*dest++ = '=';
memcpy(dest, list[i]->value, list[i]->value_sz);
dest += list[i]->value_sz;
}
/* Allocate XAVP and its SHM for string, copy into SHM */
if(!xavp_add_value(&key, &value, NULL)) {
LM_ERR("couldn't allocate XAVP\n");
pkg_free(value.v.s.s);
return -1;
}
/* Deallocate the temporary buffer */
pkg_free(value.v.s.s);
return 0;
}
```
</details>
<details>
<summary>xavp_example-2.c</summary>
```c
struct some_third_party_item
{
const char *key;
const char *value;
size_t key_sz, value_sz;
};
int add_items_xavp2()
{
struct some_third_party_item **list = some_third_party_func();
str key = STR_STATIC_INIT("items");
sr_xval_t value = {.type = SR_XTYPE_STR, .v = {.s = STR_NULL}};
/* Compute total size of the combined string */
for(int i = 0; list[i]; ++i) {
value.v.s.len += (i != 0); /* ; */
value.v.s.len += (int)list[i]->key_sz;
value.v.s.len += 1; /* = */
value.v.s.len += (int)list[i]->value_sz;
}
sr_xavp_t *xavp;
/* Allocate XAVP and its SHM for string, leave its content
uninitialized */
if(!(xavp = xavp_add_value(&key, &value, NULL))) {
LM_ERR("couldn't allocate XAVP\n");
return -1;
}
/* Build the string in the XAVP shared memory directly */
char *dest = xavp->val.v.s.s;
for(int i = 0; list[i]; ++i) {
if(i != 0) {
*dest++ = ';';
}
memcpy(dest, list[i]->key, list[i]->key_sz);
dest += list[i]->key_sz;
*dest++ = '=';
memcpy(dest, list[i]->value, list[i]->value_sz);
dest += list[i]->value_sz;
}
return 0;
}
```
</details>
You can view, comment on, or merge this pull request online at:
https://github.com/kamailio/kamailio/pull/4395
-- Commit Summary --
* core: don't copy SR_XTYPE_STR data in xav{i,p}_new_value() if it's
NULL
-- File Changes --
M src/core/xavp.c (12)
-- Patch Links --
https://github.com/kamailio/kamailio/pull/4395.patch
https://github.com/kamailio/kamailio/pull/4395.diff
--
Reply to this email directly or view it on GitHub:
https://github.com/kamailio/kamailio/pull/4395
You are receiving this because you are subscribed to this thread.
Message ID: <kamailio/kamailio/pull/[email protected]>
_______________________________________________
Kamailio - Development Mailing List -- [email protected]
To unsubscribe send an email to [email protected]
Important: keep the mailing list in the recipients, do not reply only to the
sender!
