Re: [PATCH v2 17/20] doc: Add IP provider documentation

Kris Van Hees
2025-10-09T21:45:35Z

On Thu, Oct 09, 2025 at 05:00:06PM -0400, Eugene Loh wrote:
> Hmm, just to clarify... you mean pull this patch out of the patch series so
> that it can be applied independently of the other fixes?

Ah yes, I didn't realize it was part of the 20-patch series. I think it was
an independent patch in its v1 form? If so, I prpbably was thinking about
that.

OK - let's keep it as part of the series and it will go in with it.

> On 10/9/25 13:03, Kris Van Hees wrote:
> > This patch does not apply cleanly to dev-queue. Can you look into that and
> > post a v3 (keeping the R-b)?
> >
> > On Fri, Sep 26, 2025 at 03:05:54PM -0400, eugene.loh@oracle.com wrote:
> > > From: Eugene Loh <eugene.loh@oracle.com>
> > >
> > > Signed-off-by: Eugene Loh <eugene.loh@oracle.com>
> > > Reviewed-by: Alan Maguire <alan.maguire@oracle.com>
> > > ---
> > > doc/userguide/index.md | 10 +
> > > doc/userguide/reference/dtrace_providers.md | 2 +
> > > .../reference/dtrace_providers_ip.md | 174 ++++++++++++++++++
> > > 3 files changed, 186 insertions(+)
> > > create mode 100644 doc/userguide/reference/dtrace_providers_ip.md
> > >
> > > diff --git a/doc/userguide/index.md b/doc/userguide/index.md
> > > index f3d96a4d6..18b9bcd68 100644
> > > --- a/doc/userguide/index.md
> > > +++ b/doc/userguide/index.md
> > > @@ -208,6 +208,16 @@
> > > - [fileinfo\_t](reference/dtrace_providers_io.md#fileinfo_t)
> > > - [io Examples](reference/dtrace_providers_io.md#io-examples)
> > > - [io Stability](reference/dtrace_providers_io.md#io-stability)
> > > + - [IP Provider](reference/dtrace_providers_ip.md)
> > > + - [ip Probes](reference/dtrace_providers_ip.md#ip-probes)
> > > + - [ip Probe Arguments](reference/dtrace_providers_ip.md#ip-probe-arguments)
> > > + - [pktinfo\_t](reference/dtrace_providers_ip.md#pktinfo_t)
> > > + - [csinfo\_t](reference/dtrace_providers_ip.md#csinfo_t)
> > > + - [ipinfo\_t](reference/dtrace_providers_ip.md#ipinfo_t)
> > > + - [ifinfo\_t](reference/dtrace_providers_ip.md#ifinfo_t)
> > > + - [ipv4info\_t](reference/dtrace_providers_ip.md#ipv4info_t)
> > > + - [ipv6info\_t](reference/dtrace_providers_ip.md#ipv6info_t)
> > > + - [ip Stability](reference/dtrace_providers_ip.md#ip-stability)
> > > - [Lockstat Provider](reference/dtrace_providers_lockstat.md)
> > > - [lockstat Probes](reference/dtrace_providers_lockstat.md#lockstat-probes)
> > > - [lockstat Probe Arguments](reference/dtrace_providers_lockstat.md#lockstat-probe-arguments)
> > > diff --git a/doc/userguide/reference/dtrace_providers.md b/doc/userguide/reference/dtrace_providers.md
> > > index 9f64935c6..54a018d5c 100644
> > > --- a/doc/userguide/reference/dtrace_providers.md
> > > +++ b/doc/userguide/reference/dtrace_providers.md
> > > @@ -11,6 +11,8 @@ The `dtrace` provider includes several probes that are specific to DTrace itself
> > > The `fbt` \(Function Boundary Tracing\) provider includes probes that are associated with the entry to and return from most functions in the Linux kernel. Therefore, there could be tens of thousands of `fbt` probes.
> > > - **[IO Provider](../reference/dtrace_providers_io.md)**
> > > The `io` provider makes available probes that relate to data input and output.
> > > +- **[IP Provider](../reference/dtrace_providers_ip.md)**
> > > +The `ip` provider provides probes that can be used to study IP traffic.
> > > - **[Lockstat Provider](../reference/dtrace_providers_lockstat.md)**
> > > The `lockstat` provider provides probes that can be used to study lock usage and contention.
> > > - **[Pid Provider](../reference/dtrace_providers_pid.md)**
> > > diff --git a/doc/userguide/reference/dtrace_providers_ip.md b/doc/userguide/reference/dtrace_providers_ip.md
> > > new file mode 100644
> > > index 000000000..4e6c47fb2
> > > --- /dev/null
> > > +++ b/doc/userguide/reference/dtrace_providers_ip.md
> > > @@ -0,0 +1,174 @@
> > > +
> > > +# IP Provider
> > > +
> > > +The `ip` provider makes available a probe at IP send operations in the system and a probe at receive.
> > > +
> > > +**Parent topic:**[DTrace Provider Reference](../reference/dtrace_providers.md)
> > > +
> > > +## ip Probes
> > > +
> > > +The `ip` provider provides one probe for IP sends and another for IP receives.
> > > +The module name is always `vmlinux` and the function name is empty.
> > > +
> > > +## ip Probe Arguments
> > > +
> > > +The following table lists the argument types for both the `send` and `receive` probes.
> > > +
> > > +| arg | type |
> > > +| :--- | :--- |
> > > +| `args[0]` | `pktinfo_t *` |
> > > +| `args[1]` | `csinfo_t *` |
> > > +| `args[2]` | `ipinfo_t *` |
> > > +| `args[3]` | `ifinfo_t *` |
> > > +| `args[4]` | `ipv4info_t *` |
> > > +| `args[5]` | `ipv6sinfo_t *` |
> > > +
> > > +### pktinfo\_t
> > > +
> > > +The `pktinfo_t` structure is an abstraction that describes a packet.
> > > +Detailed information about this data structure can be found in
> > > +`/usr/lib64/dtrace/*version*/ip.d` or
> > > +`/usr/lib64/dtrace/*version*/net.d`, depending on `dtrace` version.
> > > +The definition of `pktinfo_t` is as follows:
> > > +
> > > +```nocopybutton
> > > +typedef struct pktinfo {
> > > + uintptr_t pkt_addr;
> > > +} pktinfo_t;
> > > +```
> > > +
> > > +**Note:**
> > > +
> > > +DTrace translates the members of `pktinfo_t` from the `struct sk_buff *`.
> > > +
> > > +### csinfo\_t
> > > +
> > > +The `csinfo_t` structure is an abstraction that describes connection state.
> > > +Detailed information about this data structure can be found in
> > > +`/usr/lib64/dtrace/*version*/ip.d` or
> > > +`/usr/lib64/dtrace/*version*/net.d`, depending on `dtrace` version.
> > > +The definition of `csinfo_t` is as follows:
> > > +
> > > +```nocopybutton
> > > +typedef struct csinfo {
> > > + uintptr_t cs_addr;
> > > + uint64_t cs_cid;
> > > +} csinfo_t;
> > > +```
> > > +
> > > +**Note:**
> > > +
> > > +DTrace translates the members of `csinfo_t` from the `struct sock *`.
> > > +
> > > +### ipinfo\_t
> > > +
> > > +The `ipinfo_t` structure contains common IP info for both IPv4 and IPv6.
> > > +Detailed information about this data structure can be found in `/usr/lib64/dtrace/*version*/ip.d`.
> > > +The definition of `ipinfo_t` is as follows:
> > > +
> > > +```nocopybutton
> > > +typedef struct ipinfo {
> > > + uint8_t ip_ver; /* IP version (4, 6) */
> > > + uint32_t ip_plength; /* payload length */
> > > + string ip_saddr; /* source address */
> > > + string ip_daddr; /* destination address */
> > > +} ipinfo_t;
> > > +```
> > > +
> > > +**Note:**
> > > +
> > > +DTrace translates the members of `ipinfo_t` from, variously,
> > > +`struct iphdr *`, `struct ipv6hdr *`, or `void_ip_t *`.
> > > +
> > > +### ifinfo\_t
> > > +
> > > +The `ifinfo_t` structure contains network interface info.
> > > +Detailed information about this data structure can be found in `/usr/lib64/dtrace/*version*/ip.d`.
> > > +The definition of `ifinfo_t` is as follows:
> > > +
> > > +```nocopybutton
> > > +typedef struct ifinfo {
> > > + string if_name; /* interface name */
> > > + int8_t if_local; /* is delivered locally */
> > > + netstackid_t if_ipstack; /* netns pointer on Linux */
> > > + uintptr_t if_addr; /* pointer to raw struct net_device */
> > > +} ifinfo_t;
> > > +```
> > > +
> > > +**Note:**
> > > +
> > > +DTrace translates the members of `ifinfo_t` from a `struct net_device *`.
> > > +
> > > +### ipv4info\_t
> > > +
> > > +The `ipv4info_t` structure is translated version of the IPv4 header
> > > +(with raw pointer).
> > > +These values are NULL if the packet is not IPv4.
> > > +Detailed information about this data structure can be found in `/usr/lib64/dtrace/*version*/ip.d`.
> > > +The definition of `ipv4info_t` is as follows:
> > > +
> > > +```nocopybutton
> > > +typedef struct ipv4info {
> > > + uint8_t ipv4_ver; /* IP version (4) */
> > > + uint8_t ipv4_ihl; /* header length, bytes */
> > > + uint8_t ipv4_tos; /* type of service field */
> > > + uint16_t ipv4_length; /* length (header + payload) */
> > > + uint16_t ipv4_ident; /* identification */
> > > + uint8_t ipv4_flags; /* IP flags */
> > > + uint16_t ipv4_offset; /* fragment offset */
> > > + uint8_t ipv4_ttl; /* time to live */
> > > + uint8_t ipv4_protocol; /* next level protocol */
> > > + string ipv4_protostr; /* next level protocol, as string */
> > > + uint16_t ipv4_checksum; /* header checksum */
> > > + ipaddr_t ipv4_src; /* source address */
> > > + ipaddr_t ipv4_dst; /* destination address */
> > > + string ipv4_saddr; /* source address, string */
> > > + string ipv4_daddr; /* destination address, string */
> > > + struct iphdr *ipv4_hdr; /* pointer to raw header */
> > > +} ipv4info_t;
> > > +```
> > > +
> > > +**Note:**
> > > +
> > > +DTrace translates the members of `ipv4info_t` from a `struct iphdr *`.
> > > +
> > > +### ipv6info\_t
> > > +
> > > +The `ipv6info_t` structure is translated version of the IPv6 header
> > > +(with raw pointer).
> > > +These values are NULL if the packet is not IPv6.
> > > +Detailed information about this data structure can be found in `/usr/lib64/dtrace/*version*/ip.d`.
> > > +The definition of `ipv6info_t` is as follows:
> > > +
> > > +```nocopybutton
> > > +typedef struct ipv6info {
> > > + uint8_t ipv6_ver; /* IP version (6) */
> > > + uint8_t ipv6_tclass; /* traffic class */
> > > + uint32_t ipv6_flow; /* flow label */
> > > + uint16_t ipv6_plen; /* payload length */
> > > + uint8_t ipv6_nexthdr; /* next header protocol */
> > > + string ipv6_nextstr; /* next header protocol, as string */
> > > + uint8_t ipv6_hlim; /* hop limit */
> > > + in6_addr_t *ipv6_src; /* source address */
> > > + in6_addr_t *ipv6_dst; /* destination address */
> > > + string ipv6_saddr; /* source address, string */
> > > + string ipv6_daddr; /* destination address, string */
> > > + struct ipv6hdr *ipv6_hdr; /* pointer to raw header */
> > > +} ipv6info_t;
> > > +```
> > > +
> > > +**Note:**
> > > +
> > > +DTrace translates the members of `ipv6info_t` from a `struct ipv6hdr *`.
> > > +
> > > +## ip Stability
> > > +
> > > +The `ip` provider uses DTrace's stability mechanism to describe its stabilities. These stability values are listed in the following table.
> > > +
> > > +| Element | Name Stability | Data Stability | Dependency Class |
> > > +| :--- | :--- | :--- | :--- |
> > > +| Provider | Evolving | Evolving | ISA |
> > > +| Module | Private | Private | Unknown |
> > > +| Function | Private | Private | Unknown |
> > > +| Name | Evolving | Evolving | ISA |
> > > +| Arguments | Evolving | Evolving | ISA |
> > > --
> > > 2.47.3
> > >