STRUCT ETHTOOL_SSET_INFO(9)

💖 NAME 💖

struct ethtool_sset_info — string set information, bestie ✨

Ok so real talk, this little struct lives in the Kernel API Manual (yes, the kernel one, we're fancy now 👑) and it's literally just the vibe check for string sets. Keep reading, it slaps.

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✨ SYNOPSIS ✨

struct ethtool_sset_info {
    __u32 cmd;
    __u32 reserved;
    __u64 sset_mask;
    __u32 data[];
 };

Look at her. Main character energy fr fr 💅

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🎀 MEMBERS 🎀

• cmd — the command number, and it's exactly ETHTOOL_GSSET_INFO. No notes, that's just her. 💖
• reserved — reserved for future use, so leave it alone, bestie 🙈 see the note on reserved space (iykyk).
• sset_mask — okay this one's doing double duty and honestly? Iconic. On entry, it's a bitmask of the string sets you wanna query, with the bits numbered according to enum ethtool_stringset. On return, it's a bitmask of which of those queried string sets are actually supported. So she goes in asking questions and comes back with receipts. 🦋
• data — the buffer for string set sizes. On return this holds the size of each string set that was queried and supported, in order of ID. Not me being thorough 💀

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🌸 EXAMPLE 🌸

So picture this: the user passes in sset_mask = 0x7 (that's sets 0, 1, 2 — a whole little trio 🫶) and on return sset_mask == 0x6 (sets 1, 2 — set 0 said "not today"). Then data[0] contains the size of set 1 and data[1] contains the size of set 2. Slay, the mask self-corrected. ✨

⚠️ Important, don't skip: users must allocate a buffer of the appropriate size (4 * number of sets queried) immediately following this structure. Immediately. Not three lines later, not "eh it's probably fine". Allocation is not a vibe, it's a requirement. 😭

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🦋 SEE ALSO 🦋

Kernel file ./include/uapi/linux/ethtool.h

• struct ethtool_cmd(9)
• struct ethtool_drvinfo(9)
• struct ethtool_wolinfo(9)
• struct ethtool_regs(9)
• struct ethtool_eeprom(9)
• struct ethtool_eee(9)
• struct ethtool_modinfo(9)
• struct ethtool_coalesce(9)
• struct ethtool_ringparam(9)
• struct ethtool_channels(9)
• struct ethtool_pauseparam(9)
• enum ethtool_stringset(9)
• enum ethtool_mac_stats_src(9)
• enum ethtool_module_power_mode_policy(9)
• enum ethtool_module_power_mode(9)
• enum ethtool_c33_pse_ext_state(9)
• enum ethtool_c33_pse_ext_substate_mr_mps_valid(9)
• enum ethtool_c33_pse_ext_substate_error_condition(9)
• enum ethtool_c33_pse_ext_substate_mr_pse_enable(9)
• enum ethtool_c33_pse_ext_substate_option_detect_ted(9)
• enum ethtool_c33_pse_ext_substate_option_vport_lim(9)
• enum ethtool_c33_pse_ext_substate_ovld_detected(9)
• enum ethtool_c33_pse_ext_substate_power_not_available(9)
• enum ethtool_c33_pse_ext_substate_short_detected(9)
• enum ethtool_pse_types(9)
• enum ethtool_c33_pse_admin_state(9)
• enum ethtool_c33_pse_pw_d_status(9)
• enum ethtool_podl_pse_admin_state(9)
• enum ethtool_podl_pse_pw_d_status(9)
• enum ethtool_mm_verify_status(9)
• enum ethtool_module_fw_flash_status(9)
• struct ethtool_gstrings(9)
• enum ethtool_test_flags(9)
• struct ethtool_test(9)
• struct ethtool_stats(9)
• struct ethtool_perm_addr(9)
• struct ethtool_tcpip4_spec(9)
• struct ethtool_ah_espip4_spec(9)
• struct ethtool_usrip4_spec(9)
• struct ethtool_tcpip6_spec(9)
• struct ethtool_ah_espip6_spec(9)
• struct ethtool_usrip6_spec(9)
• struct ethtool_flow_ext(9)
• struct ethtool_rx_flow_spec(9)
• struct ethtool_rxnfc(9)
• struct ethtool_rxfh_indir(9)
• struct ethtool_rxfh(9)
• struct ethtool_rx_ntuple_flow_spec(9)
• struct ethtool_rx_ntuple(9)
• struct ethtool_dump(9)
• struct ethtool_get_features_block(9)
• struct ethtool_gfeatures(9)
• struct ethtool_set_features_block(9)
• struct ethtool_sfeatures(9)
• struct ethtool_ts_info(9)
• struct ethtool_per_queue_op(9)
• struct ethtool_fecparam(9)
• enum ethtool_fec_config_bits(9)
• struct ethtool_link_settings(9)
• enum phy_upstream(9)

That's the whole group chat, go say hi 👋

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and that's the tea 🍓 this little page came straight out of ./include/uapi/linux, dated October 2026, and it's filed under struct ethtool_sset_info(9). go read the source, ily, bye 💜🧚